NOBODY HAS "FIGURED OUT" HIRING !
Not Google, not Apple, no one. Sure, some places (and individual interviewers) are better at it than others. But at the end of the day, hiring is a deeply subjective process with lots of error and uncertainty built into it's nature. The subjectivity is intrinsic.
Places like Google can afford to be nonsensically picky and not suffer drastic consequences from it. They have a thick, never-ending stream of highly qualified candidates. At their volume of hiring, it doesn't matter to them if they screen out some folks that would have been brilliant hires, nor does it matter if they hire some promising but ultimately disappointing duds. All of that is OK.
Sadly, however, it seems that small shops are trying to cargo-cult Google's hiring practices. That IS harmful to the company and the candidates, IMHO. I think folks in these non-FAANG companies should get trained on how to conduct interviews, especially if they're interviewing non-senior candidates. Interviewing is a skill in itself. It's not something that comes automatically with expertise nor is it something that can be left entirely to HR drones.
The good news is, it's a very open network. We have a highly active Meetup scene, pretty regular public hackathons, annual small software conferences and un-conferences, and coworking spaces are (well were) packed.
For the most part this has worked, people new to the community are able to find jobs and the people hiring them know what hey are getting. But also like you say, this doesn't really scale to larger operations.
I'll accept the statement. But I will say that hiring from a network is at least a very different thing from hiring through a grueling set of often artificial interview hoops. It requires a potential candidate to have genuinely interacted at a higher than superficial level with a lot of people in a professional capacity. Which may not be harder than "leet code" but is certainly very different.
And yes, all the big companies have referral programs but that's mostly just a very rough first pass as a lot of referrals are basically I'm connected with this candidate on linked in. Referral bonus please.
Let's say Google would like candidates with PQ>130 with 95% confidence. Google has an error with std. div. of 15 points in measurement of PQ in jobs interviews. Google then needs to set the hiring bar at 160 PQ in order to get those candidates. This:
- screens most qualified candidates out; but
- most candidates who do screen in are qualified
Statistics would suggest this leaves you with 95% qualified candidates. A more precise Bayesian analysis will show you don't end up with 95% qualified employees, but the basic idea works -- it's still a majority. You set an impossibly high bar, so that candidates hired need to be qualified AND lucky. You discount unlucky candidates, but you don't hire (many) unqualified ones.
The problem, of course, is that all Googlers are convinced they all have a PQ>160, and are superior to everyone else. That's where you get the obnoxious Google incompetent arrogance.
And likewise, other employers looking to hire ex-Googlers are convinced of the same.
Someone just released a product that offloads Chrome to the cloud. Gmail has a very long loading screen. Hangouts was replaced by something like 4 incompatible apps. Android phones are significantly less power efficient than iPhones. YouTube copyright notices are trivial to game. Etc
Most of what makes big companies succeed or fail is in the overall culture, organizational design, incentive structure, and corporate structure -- properties of a network of individuals rather than of those individuals themselves. I think most of Google's success and failings can be explained that way, much more so than the success or fault of employee quality.
Organizational design is really hard to get right. A senior manager described it like a herd of cats. If you get them all mostly moving in a beneficial direction, you're doing okay.
That's why they pay executives the big bucks. Executives fake understanding how to manage this stuff. Most don't, but they do a good job of convincing boards that they do.
I wouldn't care about some company's code quality but in these cases Google's clout (due partly from their maladaptive hiring practices) causes these bad libraries to get grandfathered into many projects that I have to deal with.
I've worked in companies where great programmers produced horrible code, due to cultures of optimizing to productivity metrics / features shipped, rushed timelines, and interrupted work schedules with meetings, requirements changes, and people multitasking projects.
I'm not arguing one of those is better than the other. Running a business is about tradeoffs. I am not particularly impressed with anything Google has engineered in the past decade or more. The original search, gmail, Google Docs, Android, Maps, and a few others were brilliant, but those are a long time passing.
On the other hand, I'm not ready to condemn anyone working on those over that. Competence is situational and context-dependent. I also don't have insight into Google business decisions. Google revenues are growing exponentially, so they're clearly doing something right.
Makes me curious about if you have thoughts about how to find people who are good at that stuff for real (not just faking)
Place the bar high enough and you will get more and more people far into the tail, and less and less people that actually fit your bar.
A lot of really good people are discouraged by repeated rejection. However, high levels of rejection of very qualified people are built into this (and many similar) systems. You have to be qualified AND get a lucky die roll to get in the front door. Once people stop taking rejection personally, they can start acting more rationally, and there's less emotional harm. People feel really bad about themselves otherwise.
There are back doors with less luck involved.
Corporate arrogance isn't a property of individual personalities. Most Googlers are perfectly nice people. The Google corporate culture is a whole is rooted in a deep superiority complex and dripping with arrogance. Google believes it knows better than its users, and that translates to all aspects of product design. If you moved those same engineers to a different company, you wouldn't have the same behavior.
I'll also mention that each organizational design has upsides and downsides.
This culture seems to work well in Google's early markets (e.g. search) where users are statistics, and where most problems are hard algorithmic problems, and users are secondary. It has upsides in B2C markets like Google Docs or Android. It crashes-and-burns in a lot of B2B markets, like Workspace or GCP, where customers have a high degree of expertise which ought to be respected.
I'll mention a lot of fintech companies, as well as elite universities, have a similar culture. Those are domains where it leads to success as well.
Instead, you should try to find lots of correlates of PQ and measure them regularly.
Because of this, I often hire people I've already worked with. I'm also often hired by people who've already worked with me. I hate that this leads to a very homogeneous experience... or even what might seem like gatekeeping. I've just found that the best indicator of how a person will perform, is already being familiar with their work.
In my, admittedly not super extensive experience, I tend to believe that about 1 in 10 companies actually knows how to run a hiring process. I'm not sure precisely what kind of error bounds I'd put on that, but I doubt I'm off by more than a factor of 2 either way.
This might actually be part of the retention strategy. If everyone who works at FAANG knows that they're somewhat lucky to get in, regardless of ability, it means they are less likely to jump ship. What's the point in applying for another job when you're already paid well and it's unlikely to end in anything but lost time? You're unlikely to win a 10% lottery twice, given the amount of time you'd bother investing.
The 'FA.N.' part of it maybe: https://en.wikipedia.org/wiki/High-Tech_Employee_Antitrust_L...
If I change jobs, and find myself in a good situation, and need more head-count, I'm going to reach out to people I like that I've worked with before, see if they might be interested in a job change. I know I can work with them, know we'll build good stuff.
There's a constant drive in FAANG to hire more people, most teams have open headcounts. To the degree that it's extremely hard to build up that funnel of candidates. If my team has a head-count of 5, that realistically means I've got to find a bare minimum of 30-40 candidates to enter in to the pipeline from somewhere, to maybe get close to that target. That's a slightly optimistic conversion rate. Now scale that up across a company with thousands of teams that are hiring. Getting that pipeline filled on that scale is crazy. It's just one of many reasons why FAANG go all in on college hiring events.
I can almost 100% guarantee to get someone I've worked with in a FAANG co-worker through the interview pipeline and in to a job. They know their shit, they know what they're doing, and they know what the process is like.
[1] https://en.wikipedia.org/wiki/High-Tech_Employee_Antitrust_L...
I am not looking externally until I'm sure I'm done at AWS. I've done 80+ interviews here, and I'm consistently amazed by what drives people to say "The candidate wasn't up to the coding bar". As far as I can tell, you are almost never up to the coding bar. I think we interview so many people just to remind ourselves that if we leave, we aren't getting back in.
Just to head off the "So why don't I argue for change?" questions, I'd rather work on self improvement than fight tooth and nail to make the hiring process a little bit better. I'll let somebody else add that to their promo doc.
I never interviewed for the AWS side of the house since I knew I wanted free time, and a life.
It's the bar raiser's job to make sure that the hiring manager doesn't just hire people to fill seats. More than once, I've seen bar raisers override hiring managers when there was compelling evidence from the technical interviewers.
At least in my org, you don't get the job if you don't raise the bar. Period.
I had plenty of times where an entire hiring pod would incline on a candidate because they had the soft skills we were looking for in that role and we knew we could sharpen their technical skillset in house. You don't have to be a rocket scientist to work at a FAANG... you just have to be interviewed by a team that is hungry and likes you.
You're evaluated against people in the same role, not the entire team. But, yeah, the idea is that the hiring standard (the 'bar' in Amazon terms) is always getting higher.
Same as there is no amount of money you could give me to end my life, a position which I assume is shared by a vast majority of humans.
Time is not money. It’s not even close as an exchange rate. I would never put myself through these types of interview processes (not to mention that I would assume that sort of thing to be indicative of the job itself and company as a whole) because I value my actual life and dignity far and above what I value as an upper middle class income.
That always works out well.
Pretty sure a lot of older parents would take a deal with lethal injection + $1M for their kids to inherit.
I am at least 90% sure that part of these interviews is to filter out people who these sorts of views. These employer would much rather have someone who wants to work 100 hour weeks and be the 'hero' over someone who works exactly 8-4 monday-friday and then goes home.
Part of the problem is the sheer scale of hiring, but I think most of the problem comes down to the lack of feedback or evaluation mechanisms on the interviewing side.
They train you up, half a days worth, training tells you not to be an arsehole, not to ask stupid questions, not to have unreasonable demands of candidates, not to be biased. They don't train you in valuable skills like active listening.
Next thing you know, you've done training, and you're interviewing candidates every week or two (or more often), and there is zero feedback mechanism. No one evaluates your interview questions, no one asks candidates to provide feedback on the interviewers. No one looks to see if you've got unreasonable expectations as an interviewer, or have your expectations set too low.
You do have to do a post-interview group discussion with the other interviewers to make a yay/nay decision, but it's super easy to present what you did/asked in a positive light.
The whole system is designed around the interviewer being right and infallible. Is it any wonder the process is so completely and utterly broken?
edit: > or have your expectations set too low
This is where I bias towards in worrying, imposter syndrome and all that jazz. I've made a conscious choice to not raise that bar higher. I think the questions I ask are good, I think they're set up well enough to encourage candidates to go as deep as they feel comfortable with. I try to design them with no one true answer but have a few in mind so I can go where the candidate goes.
Are you saying each interviewer just makes up their own questions?! That's ludicrous if so. Where I work, we have a standardized pool, with standardized evaluation criteria.
Obviously the drawback for FAANG is that standardised questions would rather rapidly leak. Very quickly you'll just end up with candidates that know how to answer your questions.
Where I work now, it's a mix of pool questions ("soft" skills) and interviewer-made questions (technical skills), but it's not a hard and fast rule to use the pool questions. I rarely use the precise wording for the pool questions, and instead adapt them to match the conversation with the candidate.
1. We trained 4-5 times on each type of question. The first few were shadows, and then we did reverse shadows where someone watched us give the interview and gave feedback later. In one category I asked for and was allowed to reverse shadow an extra 1-2 interviews.
2. There was auditing. In debriefs where you discussed the candidate and reviewed notes, the debrief lead was supposed to closely examine what questions you asked and how you conducted the interview, with the explicit goal of making sure that the interview was conducted within spec and your recommendation made sense given performance. Shortly after I was certified to do interviews, a debrief leader (correctly) identified a major issue in an interview that I had conducted. That candidate was given another interview in the same category. Although I didn't face any official sanctions, it was definitely an embarrassing experience and made me handle future interviews more thoughtfully.
Overall, I was fairly comfortable with the rigor of the process that I saw. I'm certainly not saying the process is perfect but my experience did not align with yours.
(the "lizard brain" is a myth by the way; I think you're confusing it with unconscious bias of heuristics, which is not what the triune brain theory was about)
Whatever metrics that google is using in their interviews have probably become worthless in the past decade as people game the system.
And the NDK clearly is anything but modern C or C++.
I’ve heard it referred to as “C+-“.
Apple mostly cares about LLVM based tooling in the context of Objective-C and Swift, Metal is C++14 dialect, and IO/Driver Kit require only a subset similar in goals to Embedded C++, so that leaves the remaing of the clang community to actually provide the efforts for ISO C++20 compliancy.
Which one is best for open source is debatable.
Permissive licenses make it easier for companies to make proprietary software, or even a closed source version of the original project.
Copyleft licenses (like GPL) are intended to promote free/open source software but they can be a legal headache, which can make users favor proprietary solutions.
On HN, I think that people tend to prefer permissive licenses (but complain when large companies "steal" their work, go figure...).
"Data-oriented programming" (to distinguish from object-oriented) is largely C-style C++ that is written for performance rather than reusablility/abstractness/whatever. In the embedded programming world where performance is paramount, a lot of people have low opinions of many C++ features. One could also never completely trust compilers to implement everything correctly.
I come from an embedded background, and understand that.
Aren't they the company that pretty much requires an Ivy-League sheepskin to be a janitor?
My pet theory is that HR minions feel compelled to portray their role in the process as something that adds a lot of value and outputs candidates which meet a high hiring bar, even though in practice they just repeat meaningless rituals which only have a cursory relationship with aptitude and the engineering dept's needs.
This is the first time I've been involved in coming up with the process, but from what I've observed, it's a similar situation in other organizations.
That is simply not how things are. The hiring bar is designed and upheld by people on the same software engineering job ladder as a candidate. The role of recruiters is primarily coordination. The role of HR is compliance with local employment laws.
"The key point here is our programmers are Googlers, they’re not researchers. They’re typically, fairly young, fresh out of school, probably learned Java, maybe learned C or C++, probably learned Python. They’re not capable of understanding a brilliant language but we want to use them to build good software. So, the language that we give them has to be easy for them to understand and easy to adopt. – Rob Pike 1"
"It must be familiar, roughly C-like. Programmers working at Google are early in their careers and are most familiar with procedural languages, particularly from the C family. The need to get programmers productive quickly in a new language means that the language cannot be too radical. – Rob Pike 2"
Sources:
https://channel9.msdn.com/Events/Lang-NEXT/Lang-NEXT-2014/Pa...
The candidate hated the interview, claiming it was discouraging. Coding is erratic, talent is strange, it really is a craft and we still don’t know how to reliably raise someone to competency.
1. The candidate was a complete and utter fraud and their previous (and apparently well-regarded) employers were too stupid or negligent to notice this, wasting literally millions of dollars (48-21 * $100,000+).
2. Something about the interview failed to let this person demonstrate the skills that had kept them employed for two decades. Maybe their mind went blank under pressure, or at the end of a long day. Maybe they got hung up on something trivial (that a quick search—-or nudge from the interviewer—-would have resolved), or the question was unclear.
Fizz buzz was a great question in that it had pretty much a Boolean success criteria.
If the interviewer only says "Write String.contains that passes these test cases" goes back to playing with their phone, several things may happen. One person will take that absolutely literally ("It's a test; better do as I'm told"), and you'll dismiss that apparent garbage or move onto the "real" assessment where they're hoping to shine.
Another will get bogged down in something the interviewer regards as a distraction, and "waste" a bunch of time on something the interviewer regards as a distraction. "He handled unicode, but not substring matching (KMP or Booyer-Moore) or vice versa." Maybe someone will goldilocks it and hit the right (not-explicitly-specified) balance of (also unspecified) features and time, but...
If you structure it as "Please, do the dumbest possible thing and we'll iterate"--and don't hold that initial pass against them--I could see it working well.
That would tell you if their workflow would fit your company much more than knowing how to run a coding challenge would.
It is still a very useful test.
Personally I am a much bigger fan of using FizzBuzz as a gate than an algorithm question. I think algorithm questions optimize for the kind of developer who doesn't mind memorizing algorithms to get a job, which might be a useful skill, but you can test that same skill of memorization using FizzBuzz, and then you don't end up also filtering out people who can code but don't care about memorizing algorithms.
In any case, I always think it's worth using their solution as a jumping-off point to ask other, more language-specific questions. Things like: how would you change this if it was intended for use in a FizzBuzz library, how would you annotate this if you needed it to be injected as a Spring dependency, why did you use a for loop instead of a Java 8 stream (or vice versa), what are the implications of declaring this thing as final or static, can you write a unit test for this, and so on. That's when you can get past the point of memorization into figuring out if they actually understand what they typed, which is helpful to ascertain their level.
well, I mean, you get to ask what you like... but this is how you determine if someone understands what they've typed on a conceptual level?
For me there are basically two questions to answer when I am interviewing someone. The first is if they have any real programming ability at all, which hopefully FizzBuzz should answer. (Many people do not pass that threshold.) After that I'm looking to figure out where they could fit into the team, or the company. That means seeing if they are already familiar with the frameworks they will be working with in the position (usually, but not always the case for junior applicants who have held at least one job before), but then also if they can speak critically about some of concepts used in those frameworks, and perhaps compare different approaches that have been taken to solving similar problems over the years (if they are more senior).
It's not a wrong answer if they don't know the framework or the concepts behind it at all, since they might be switching specializations, but that's important to know at the interview stage because they might be better suited for a different role than someone who is deep in the framework and more likely to be able to hit the ground running.
My question is: what happens after people pass fizz buzz? Failing fizz buzz is how you filter people out, but it's unlikely that coding up fizz buzz passes the technical screen. What kind of questions do you use to establish this, once you're past fizz buzz?
I've failed far more tech screenings than I've passed. I could easily do fizz buzz, and when I've prepped for an interview, I could some tree and set permutation stuff. But the questions get so much more difficult than this. Since difficulty varies, an example of a difficult question for me is "find all matching subtrees in a binary tree" (at the whiteboard, in 45 minutes). When I got feedback about the no-hire, the explanation was that I had a good grasp of algorithms and made some progress, I didn't solve enough of the problem in code (tight pseudocode would have been ok) in time allotted (again, this was ~45 min at the whiteboard, one in a series of 5 one-hour technical exam style interviews during a day of interviewing).
I can't claim to be a great coder. I have understood how to code merge sort and quick sort and more complicated tree structures, and I could do them again if I studied and loaded it all back into short term working memory, but I'm content to know how the algorithms work generally and get back into the details when I need... but when anyone mentioned "Fizz buzz", I do insist on stating that my impression, based on quite a few interviews, is that fizz buzz isn't what is screening out software engineers. Lots and lots of people who can write fizz buzz (and build and print a binary tree pre order and post order, and do dfs and bfs, and solve problems with them) are still frequently screened out.
I'm at the point where I just won't do tech interviews anymore (or take home tests). I won't study for exams or do mini capstone projects for an interview that may or may not work out. I would do these things for a degree or licensing exam, but not for a job interviews. It's just too much of a time sink.
I accept that this may cost me good opportunities (in fact, it has), though of course I don't know if the interview would have gone anywhere, other than costing me another long prep session with "cracking the coding interview".
I'll finish the way I usually do, by 1) acknowledging that you are free to interview how you like, and that nobody owes me a job, and 2) mentioning that many companies complain incessantly about hiring difficulties without realizing that their own interview processes may be filtering out talented people and that nobody owes them an employee either.
We tune up a little bit the difficulty. The point is to start a conversation and see what the candidate knows about, ¿does he knows about time complexity?¿differences between passing by reference/value?. Afterwards we talk about the technology that they use, what they like, and what they will like to use in the future. Just to see if they read about their field and are able to talk without saying something egregious.
And if they do fine we bit the bullet and hire them.
> nobody owes them an employee either
Now that I am "in the other side", I can see a lot of things that will definitively would improve the problem at micro/team level, like posting salary or increasing the WFH days. But ¿would they improve at macro/company level? The things is, companies, including tech companies, from small startups to big corps, usually have much more problems than the quality or quantity of their software.
(signed, someone that has been rejected, and will be rejected, to more interviews that he has passed)
There are certainly a few. The job market, being a combination of people who want new jobs and those that can’t keep their old ones, is undoubtedly enriched for them.
Even so, it seems unlikely to me that there are anywhere near as many as most people say. You certainly don’t have to hire someone who flubs your interview, but you also don’t have to assume they are frauds.
I’ll estimate zero to 10% wildly incompetent. Many of the folks who aren’t able to program find other ways to be useful: Testing, requirements, prod support, sys admin, config. It’s not even clear they couldn’t program, but maybe came to prefer the other work at some point.
What’s your wildly incompetent estimate?
> The job market, …, is undoubtedly enriched for them.
30%, minimum. I was hired alongside a guy with a fantastic resume. He pushed zero lines of usable code in 4 months. When he left I purged about 20 files which were tests that were just completely commented out (but I guess those count for LOC according to github's crude measure). I would say that not only was he incompetent, he was worth negative (thankfully, nothing critical) - Maybe in order to cover his tracks? he had moved certain classes of tagged tests (e.g. skip, broken) to "ignore" status instead of 'yellow star'/red dot, I now, months after his departure, have a pr reverting those changes months after because I didn't notice he had done that. Thankfully it had not covered up any major defect in our codebase (someone could have left a corner case test as "broken" with the intent to fix it later and wound up forgetting to and sending it to prod).
But hey. Programming isn't that bad. In the physical sciences it was 60-70%.
How was this not uncovered during code reviews?
I think the reason why every developer tends to have a story about these sorts of incompetent colleagues is not necessarily because 50% of their colleages are incompetent, but because even if just 2% (one person in the department) or 5% (one person in your larger project team) is incompetent, that can be enough to cause a seriously negative impact.
I'm sure I'm on somone's list of incompetent bozos for an interview that went like this: "Please, describe Python programming language." That's it. I had no idea what I was supposed to be doing, and the two fellows interviewing me would not elaborate.
I talked about what I had done with Python. Stony stares. Do I talked about the nature of Python itself (interpreted, multi-paradigm, lexical/LEGB scope, the GIL). Stony stares. I wrote some trivial programs on the board. Stony stares. Had I brought an actual snake, I might have tried to charm it.
At the end, the CEO told me they weren't overwhelmingly sold on me, but would think about it. Never heard from them again.
There are so many "developers" just faking it, I can certainly understand using a test that would reject 90% of the good candidates if it could reject 99% of the bad ones.
This was the introductory question before launching 200 threads and asking him to solve the deadlocks/inefficiencies, which was the real question supposed to let him show off his skills in front of my employees, specifically crafted for him because I wanted to persuade my employees he was an excellent hire. So he had a taylored chance to show off his skills but failed at the introductory question.
But on the other hand, how can you be asked “Here’s a substring, return true or false if it contains the substring, this is the introduction of 5 questions so don’t sweat it” and not just write two nested loops and an if? I’d pass on UTF8 problems, but when you’ve been working with Java for CRUD apps, you still should have your UTF8 correct. This is how you end up with passwords that must be ASCII because the programmer is bad.
People's brains just occasionally lock up.
And if the candidate was able to do this in 6 minutes, what would you have thought? "Great, let's hire"?
In my humble opinion, the question is a waste of time either way. You'll get much further trying to probe what the candidate does know rather than randomly creating an exercise that you think they "should be able to do if woken up in the middle of the night". People forget how stressful interviews are and how easy it is to assume shared context.
The fact that your employee was able to do the test might be indicative of the fact that you share context with the employee that you did not share with the candidate, thus confirming your bias.
This! When giving interviews last I really worried if the questions I asked where just indicative of my own Dunning-Kruger effect.
i.e. Do I only ask questions I already know the answer to and not questions I don't know the answer to?
If I do then am I just filtering for people with the same background and knowledge and missing out on people with other skills I don't know, because they're in my blind spot, I need yet?
I've been advocating for a "coding interview" where both the interviewer _and_ interviewee draw some random question from leetcode or other problem bank, and try to work at it together.
This would show collaboration skills, and you can tell pretty easily how helpful the candidate is with his/her contributions, and whether you find there is an impedance mismatch somewhere.
It probably also maps more closely to the kinds of interactions you'd have after the person's been hired.
I think it would also help calibrate: if you can't figure it out, is it fair to expect the candidate to figure it out? Maybe it's just a hard problem!
Multi-lingual support seems really really hard, especially in six minutes. I would think most people would need to look at technical (i.e., unicode) and linguistic references to get it right.
Should does the ligature f l match itself, or the ASCII constituents 'f' and 'l'? How about combining vs. pre-composed characters? Some Chinese characters show up in other languages (Japanese, Korean) and are sometimes split between Hong Kong/Taiwan/Mainland language tags too. In fact, there's a mess of work devoted to this ("Unihan" https://www.unicode.org/versions/Unicode13.0.0/ch18.pdf). Having figured out what you can do, you then need to decide what you ought to do. Not being a Chinese-speaker, I have no idea which options would seem natural....
In fact, having written this all out, there's no way someone "solved" it from scratch in six minutes. It would be a great discussion question though....
for (int i = 0 to text.length() - substring.length()) {
boolean found = true;
for (int j = 0 to substring.length()) {
if (text.charAt(i) != substring.charAt(j)) {
found = false; break;
}
if (found) return true;
}
> What was the goal of the question?
This is the introductory question before solving concurrency problems, because it’s much easier to understand what a thread does when you’ve coded the body yourself.
> Why did you want the person to implement a contains method?
The job is CRUD + integrating with Confluence + parsing search queries from the user, so finding “<XML” in a page and answering “Yes! This is totally xml, I’m positive!” is a gross simplification of realistic tasks in the real job (and in fact in most webapps), with characters instead of XML or JSON.
I have the feeling that you think this question is entirely abstract, but I both tailored the exercise because he touted being good at improving app performance on his resume (including using JProfiler) and I took care of using a realistic on-the-job example.
> Did you really want to verify they understood String implementation in Java?
Well, what consumer product can you work on if you trip into all UTF-8 traps? Telling customers “Just write English because we can’t be bothered to learn the easy thing in Java that handles UTF-8 properly” is… is acceptable unless he also fails the fuzzbizz test. And once UTF8 is mastered, it’s good for life! I wouldn’t mind teaching him if he didn’t fail the rest, but as a senior you should really know the difference between .getBytes() and .codePointAt(i).
> If the candidate was able to do it in 6 minutes, what would you have thought? “Great, let’s hire”?
The 4 other questions were classic gross concurrency errors, tailored because he touted it in his resume and I wanted him to shine. A senior should be able to guess them blindfolded as soon as I tell them “There are concurrency problems”, without even looking at the code ;) Volatile, atomic, ArrayList non-synchronized, 200 threads for a connection pool of 10, a DB accepting 7 cnx (note the prime numbers make it easy to spot which multiple is causing the issue), and strings of 10MB each with Xmx=100m, if he finds any 3 of the 12 problems, and 2 more with help, I’d hire him. If he ditched the code and postes tasks into an ExecutorService (as they teach in the Java certification level 1), I’d hire immediately.
1) We want to test concurrency but start with implementing String#contains.
2) You have to know how to implement String#contains because you might use contains in our environment (not really, but theoretically, so you better know how to implement it).
3) You must absolutely avoid basic UTF-8 traps because users use UTF-8.
Neither of the above tells me what would you gain if the candidate nailed the question. It just tells me that:
- Your team might or might not use contains to verify something is XML (I truly hope not).
- Your team uses UTF-8 strings (which is one piece of the shared context that the candidate probably does not have).
- You tested candidate abilities of performing under pressure rather than testing their knowledge or skill.
- You are trying to hire the exactly same senior developer as if you promoted someone on your team with your codebase.
You come to the interview full with assumptions and biases about what a senior candidate absolutely must know instead of seeking what they bring to the table and why they call themselves senior. Let me tell you there are lvl 4 and 5 Java candidates that have never touched UTF-8.
Finally, and let me blow your mind here, there are senior developers that haven't really used String#contains in the last X years of their career either.
I don't know what was the quality of the candidate, but I feel, from my limited PoV and lacking all the info, that your interview process is deeply flawed.
I also completely fail to see what a CRUD app (i.e. java + db) + shooting REST requests to confluence has to do with your concurrency questions, as in interview != job fit, but that might have to do with some missing context.
My then-co-workers liked to ask harder algorithmic questions but I wanted to give the candidates a little bit of a break with something easier.
It didn't always work, but at least I tried.
What were you trying to tease out from the problem statement?
I am not a Java programmer but it took me 30 seconds to find the contains() method.
Makes a lot of sense, you could solve all these questions without knowing specific algorithms as long as you are good at problem solving - which is, I assume, the intent of the process.
Obviously it doesn't always work like that.
While it's probably not what an interviewer is looking for, having the most common solutions memorised gives you an advantage of time. A coding interview usually consists of two challenges. If you get stuck on the first one and take too much time to answer it, you won't have enough time to go through the second one.
To avoid the code printer perception you can always go through an explanation what alternative solutions could be applied to the given problem, what their complexities would be and why the one presented is the best.
And yet, they routinely do pass these interviews.
You could solve all these questions as long as you are good at problem solving, *given enough time*.
However, with tight time constraints and perfomance pressure, the only way you could solve all these questions is memorizing and practicing all these algorithms.
Apparently the correct answer is to use "Robert W. Floyd's tortoise and hare algorithm", which is trivial to explain and code.
The catch?
It took a decade of computer science research between the original statement of the problem and Floyd discovering the solution.
So... no worries, you have an hour, a marker, and a whiteboard. Your time starts: now.
The tortoise and hare algorithm is not the foundational skill required to make software work the way an understanding of motion is for building structures. That's why it's often omitted from educational material yet these people are able to produce usable software after even something like a bootcamp (which I guarantee basically no bootcamps ever touched this algorithm).
I'm not sure I approve of asking even more well known algorithms like Djikstra's algorithm or A* in a job interview, unless the role was something that specifically required that area of knowledge like building pathfinders for video games or robots or something.
You’re expecting the mechanical engineer to recall something they learned about kinematics, not derive it on the spot. It’s a test of knowledge, rather than cleverness. The equations of motion are also more central to physics and engineering.
A decent programmer should know that linked lists exist, their general properties, pros and cons, etc. However, cycle detection is not a particularly common operation, so not knowing Floyd’s algorithm tells you very little—-and their failure to do years of research in 45 minutes even less.
Also, it took around 13.8 billion years for Newton to do what he did.
If they actually aren't looking for people who just cram CTCI or leetcode, coming to this answer from first principles is demonstrably far more difficult than you'd expect achieved in an interview.
These sort of questions have an incredible recency bias, and have zero relevance to engineering competence.
Of course; how else do you do back-door age discrimination?
"So we specifically asked for linear time."
"Uh, yeah, I did it in log(n). That's better."
"It doesn't match what's on this paper they gave me. Thanks for your time. We'll be in touch."
No such avail. In fact, unless these algorithms and problem solving methodologies are baked into your memory there's no way you are white boarding a Leetcode hard level problem in an interview.
What I was impressed at an Uber interview was their system design interview process - which basically boiled down to 'how do I abstract retrying a 429 - rate limit exceeded.
What I take is that - the interviewer is expecting a very specific solution even in an open ended system design question. It's like throwing a needle in a haystack at you and expect you to get to the needle in like an hour :).
They're probably looking for some sort of variable refilling leaky bucket implementation, which is funny because I believe this is exactly what they do internally. It was probably the task the interview had in front of them in their day-to-day and wanted you to do it for them!
This is a fair design question for a senior role (which this sounds like) that promotes disccussion, but expecting a specific solution is really only testing "does this person match my preconceived ideal for what a <dev> is?" which is really dangerous and has very little value.
I thought it was exactly those who Google wants to pass. Anecdote: ex-colleague of mine who is not specially bright studied 3 months how to "crack the coding interview" and got a job at Google. His knowledge about algorithms and data structures was like mine: I know what a tree is, I know there exists operations one can perform on them and some of them are more performant/efficient than others... but I would need to Google how to "reverse a binary tree" if I had to do it in less than 1h.
Plenty of times where I've used trees because they're the logical representation of the problem (ever had a field called "children" in your code? HN comments are a tree. Etc.)
Sounds bright to me.
I think your weights are way off.
The biggest difficulty for most seems to be that they don't know what "reverse a binary tree" actually means. It sounds kind of mathy and opaque, so I get it, but candidates should be able to have a dialog to figure out what the requirements mean. And on the flipside interviewers should be ready to have that dialog and not count not knowing the term by heart against the candidate.
This problem to me feels qualitatively different than the "rabbit and hare" algorithm for finding a loop in a linked list mentioned by another poster. That one needs a non-trivial algorithmic insight that just might not come to you during an interview. The solution to "reverse a binary tree" flows out of the structure of the problem statement as long as you have the fundamental skills for walking and manipulating data structures and the conversational skills to understand the problem, both of which seem fair to test for.
That's just absurd. If someone with no "algorithm" experience who was a good problem solver had to work out an answer from scratch for the interview its almost certain they're going to find the brute force answer and FAANGs pretty universally want the most efficient one so these people would routinely fail.
Its totally clear that what FAANG hiring optimizes for is recent CS graduates who passed tough Algorithm weed out courses at well known colleges in the past 18-24 months. They are young with no families or obligations and are happy to work 12 hour days at Google because they have hip open offices and ping pong tables.
No one knew who they were interviewing or what was on the resume until they glanced at it while walking to the interview room. I suspect all interviews and the process are just made up as folks go along, and half the time you get a gig or not mostly based on if one of the people you talk to is in a good mood or not.
This is in contrast to tailoring each interview to a candidate's background.
With that, I think looking at a candidate's resume 15 minutes before an interview is not that unreasonable.
What am I missing?
(edit: this is meant for IC roles rather than management)
I've updated the profile to include "No FAANG companies" because I'm pretty sure I would not be a good fit for them but that didn't stop their recruiters from pestering me.
For my LinkedIn I listed minimum requirements and it saves me 100+ inquiries per week but I still get a ton of irrelevant jobs.
I took a different offer in the end, but the recruiters reach out every few months for a chat.
(This is a massive oversimplification, of course, but you get the idea.)