What I learned from doing over 60 technical interviews in 30 days

I'm going to have to disagree with the cover letter advice.

I'm sure there are people out there who appreciate well written cover letters. They are a tiny minority. How do I know this? Some years ago I started applying and would always type up a custom cover letter whenever a position allowed me to upload one.

Every time I got a call, I asked them if my cover letter played a role in their choosing to call me. The response was always "Oh you wrote a cover letter? Let me check it out."

Not one person had read it.

Not. One.

Those things take a while to write, and that time is better spent applying to more jobs. I quickly stopped writing them. Sorry, but unless you are getting a job via networking, it really is a numbers game.

If I were sending my resume to someone who I know is not a recruiter/HR, then I do take the time to write one. Otherwise, I don't.

Hotter tip: toss the advice from people who interview a lot and aggressively and seek advice from the people who wander into opportunities seemingly without effort. Ask them how they approach their job search.

Most of this advice is bad or fixes problems that come from scattershooting an interview process by bulk for nonsense you don’t even care about.

This blog post outlines the most miserable way to do a job search. And the way to get rejected a lot.

I have been a freelance coder for more than 20 years, I have worked on a lot of different subjects, I wrote compilers, small embedded kernels, shipped dozen of products, did thousands of OSS contributions…

But I would be terrified by one of those interview.

For example: How can you write a sort algorithm with 0 error in such a short time, without reference? I would never be able to do that. I "know" how they work, but with qsort() since C89 there is very little reason to write one, except if you have special needs, and those special needs are "the problem" not the sorting algorithm.

Or I would be unable to write the TCP handshake procedure on a piece of paper with just a pen, even knowing I wrote a mini TCP stack a few years back for an embedded chip.

I can think of a million technical questions for which I have no answer, how do you cope with that in an interview (with the added pressure…)?

I am genuinely wondering if I am bad, or if it is those "coding challenge" that are inappropriate.

This guy obviously loves interviews. I hate them. I am not going to practice interviews with my friends and have a real interview once a month like he advised.

Also, you can find jobs without these stupid coding challenges and time consuming processes. I never worked in a company that asked me to write code before being hired.

I've been doing some mock interviews for friends and I've had a couple realizations. Almost everybody gets nervous at interviews. I get nervous, you get nervous, we all get nervous. However some are able to tamp down the nervousness and not let it show. There's nothing wrong with being nervous, but it is useful to project confidence. Stuff like smiling, speaking up, even providing a light joke can help you seem more personable and get you ready to perform.

When I have an interview, I tap into techniques that I used when I competed. I used to do a very individual based sport. Tournaments would be stressful since your performance solely depended on you. Therefore I learned a bunch of techniques on how to keep your mental game going. Techniques such as listening to music to hype you up, having certain ritual foods or drink, self talk, meditating, etc. One accomplished athlete I knew talked about how he'd tell himself that he'd put in the training to be the best. Therefore he knew that he could do it.

It's a little weird viewing an interview as a competition but it's really about getting through a stressful, high risk/reward situation with the right mental game.

What I’ve learned from giving and receiving technical challenges over the years.

Don’t.

The only thing these challenges do is determine whether someone can do your coding challenge. No indicator at all about their ability to actually solve your business problems.

Instead, give the applicants an offline evaluation solving something within your actual dev/testing environment. Pay them for their time. 2-4 hours.

The best interview process I ever had culminated in me logging in to a testing system and working on what I believe was an actual problem at some point in the companies history. The IDE and DB was there and ready to go with some docs and a ReadME. They told me ahead of time what rate they would pay me and that they would pay up to 4 hours. If I decided to spend more it was on me. And I had 4 business days to do it.

"Like a skilled surfer, I wanted to learn to ride the high pressure waves that came with interviews."

Yeah, bro, that's not surfing. Good surfers respect the big waves. No coder is going to respect a bad interviewer. But I trudged on through the article and ran into this gem:

"There will be times when you’re stuck. And this could be caused by a number of reasons: you don’t have the requisite knowledge, incorrect assumptions, missing details, and so on.

"I used to think that at such times I was being judged by how fast I could come up with a solution. So I would be quiet, thinking, not communicating with the interviewer, just thinking.

"And this is where a lot of us get it wrong. I get it, you need some alone time to think. But sorry to burst your bubble, that alone time is not when you’re being interviewed by a person.

"Yes, your interviewer wants to see that you can come up with a solution, but one thing you must not forget is that they also want to see that you can collaborate with other team-mates to come up with a solution. While companies want rock-stars, they also want team-players.

"Since your interviewer is a friend, a buddy, a team member who’s on your side and means well for you (Refer to 4), talk to them while you're figuring it out."

Yeah, the interviewer is definitely your friend, and you have to work with them as a team in the interview. This advice is gold. If you do not feel that they are a friend, you can politely ask to end the interview for personal reasons. No use interviewing further, for the same reason you can end a date if you are no longer comfortable.

>109+ applications later, I landed myself more than 60 interviews. These comprised more than 60 introductory phone interviews, 50+ technical phone screen interviews, 18 take-home coding projects, 11 coding challenges and 8 on-site interviews including 3 virtual ones.

Rearranging slightly, into filter pass rates:

  application: 55%  
  recruiter screens: 85%  
  technical phone screens: 72%  
  second tech screen: 21%  
  onsites: ?%

Obviously not every company follows the same process, but it seems like the author found it hard to make it through tech screens into onsites. So I'm not sure how much I'd weigh on their advice in that stage of the hiring process. But maybe someone with better access to the data can do a more nuanced analysis, like how often completing a code challenge led to advancing in the hiring process; I found those to be quite easy on average, but surprised to see how hard they were for the roles I was applying to -- it's not often an SRE would be assigned a programming task involving clique analysis.

What I learnt from dozens of C++ interviews over a few months in London, is that interviewers are obsessed with the tiny, niche corners of C++ that they're familiar with, and normal developers would consult the docs for, and have zero interest in whether you can write clear and concise code that solves a problem. When would I ever write my own std::enable_if.... on a whiteboard?

Years ago, C++ interviews used to be 'what's the difference between pointers and references, stack and the heap', and a bit about v-tables and memory management to prove you know something about C++.

Welcome to 2020, and language that needs to be quietly put out of its misery.

What I learned from the fact of carrying out 60 interviews in 30 days is that there are awful lot of organizations that are unable estimating technical competence and have no clue how to do that but introducing time wasting unreliable excuse activities masking gut feeling decisions. Those rushed but still overly simplistic tests only measure how good someone is in those tests, not how good someone will be in a position.

I suspect that the main problem with hiring in our industry is that coders have the unfortunate tendency to treat other coders as if they were code. We treat job interviews like they're some kind of unit test. Add this assertion, run this same unit test every time, reject the assertion failures.

Humans are not code. We don't behave algorithmically. It's well known that job interviews are very poor predictors of performance. The best predictor of performance is past performance. It's not a perfect predictor by any means, but there are no perfect predictors. Hiring is a crapshoot. We need to get over the conceit that we can hire without making mistakes. To err is human.

This is a great article, but it raises my heart rate to even read about technical interviews.

When I was younger and more stupid I was once asked to interview 20 people all in a single day to select half a dozen initial developers for a startup. This was my first task at a startup where I was supposedly to become CTO or something like that. I did it but I also learned, as you can imagine, it is pretty much stupid idea. This led me to resign from the position on the same day because I decided founders were not reasonable about making business (treating people as replaceable cogs).

Advice number 6 is the most important one and I learned it the hard way. You may be a genius but the interviewer won't know until you express yourself. Don't sit idle thinking about stuff. At least talk what are you thinking.

I was an engineer for years and then a recruiter before starting interviewing.io.

After having hosted ~60K mock interviews, I agree with one of the big takeaways here. Practice practice practice. It's not the same as working problems on your own. But after 5 or so, many of our users reach an inflection point.

As for cover letters and getting in the door in the first place, no one at large companies reads them. However, best thing you can do is find an engineer at that company and send them an earnest, short email about why you admire their work and why you want to be a part of it. Don't talk to recruiting... unless you fit a very narrow, specific mold, they're not incentivized to take risks.

Really great to the point article without any fluff. Lots of actionable insights.

The part about treating interviews as technical chats resonated the most with me and has been my personal experience as well - both as an interviewer and interviewee. If I'm going to hire you we are going to have such discussions every other week so its important how good we can collaborate.

109 applications to 60 interviews is a phenomenal hit rate.

I’m mixed on cover letters. I rarely read them, and a poorly written one can do more harm than good. They can be used to explain why a non-obvious candidate may be a good fit, but that’s usually better done via 3 bullet points attached to a referral.

Re cover letter sales pitch: Of all types of diversity among engineering team members, racial diversity is very uninteresting to me. And I cannot legally let race influence my hiring anyway.

Surely the effort you put into 60 technical interviews are great. But instead, you should focus to 10 companies you would like to join, it may turn out better as you could focus your energy and thinking for cover letter and preparation.

I had the opposite experience a few years ago when applying for jobs for after I graduated. I stopped trying to learn about each company and stopped writing cover letters. Instead, I just wrote a 2 or 3 sentence, completely generic blurb about myself, then sent it with my resume to as many companies as I could find in the area I wanted and with the tech I wanted. Only when I heard back did I actually look in to the companies.

I think a key takeaway is that less is more. People don’t have time to read long cover letters and resumes. Keep it as short as possible but no shorter. Cut out everything that’s not your best selling points.

Probably the safest way to practice is to do interviewing at your current company. There's a lot of similar skills that you need to get good at to be good at interviewing others, and if you work at a good company, they'll want to train you and give you feedback on becoming good at interviewing others. You'll also get a much stronger understanding of what interviewers look for, how they evaluate, what a good interview looks like. So, once you're interviewing for a job yourself, you'll know how to recreate that same feeling.

Worth having a multi month break at some point in your career where you spend most your time practicing and taking technical interviews. It makes you a better programmer and problem solver.

> The interviewer isn’t there with you and so does not have the luxury of seeing other non-verbal cues like your hand gestures or nuances.

But they can still hear nuances in your voice, more than you might expect. Use a headset, don't hold your phone, and stand up when you are on the call. The movements you naturally make when not locked to a chair holding a phone against your head will come across as better emphasis in your voice.

I'm one of those people who apply like at two, three jobs and get offers from all of them. The phone screen is the most important IMO, that and a good recruiter.

People get all pissy about it and treat their recruiter poorly, which is highly unprofessional.

The biggest problem right now from the hiring viewpoint is that there are a lot of "senior engineers" with 2-3 years experience expecting a high salary, when you can easily find good remote programmers working in other countries who are not going to be asking that sort of money.

I think now that remote will become the rule, then it's an even bigger disadvantage for those who are looking only to code and that's it. What I think will happen more and more is that the only developer who will work inside the company is the lead developer, and the rest of the team will be all remote.

Soft skills are King.

Of course, you could go live abroad and work contracts. Not a bad life honestly. I think about it a lot these days. For those junior devs and mid level devs, highly recommend this, especially if your first language is English.

How should a deaf programmer conduct phone screens?

> I stopped seeing these in-mails as noise in my inbox and started making the effort to reply to all recruiter in-mails, even for positions I was not interested in. By doing this, I succeeded in building a network of recruiters that have become a rich resource if I have to switch roles in the future.

Recruiters are not your friends who'll help you out in time of need. My experience is that they don't even look at your profile unless you reply.

I'd wager a bet (and this is only my personal opinion) that if you lose your job for whatever reason, this will be a red flag to most of such "network" and when you need another job, they'll avoid you like the plague. An addendum to this wager would be that if you get hired by some high-prestige company (think Microsoft, Apple, Google, LinkedIn, ...), they'll swarm you trying to poach you for whatever you have open (so exactly when you don't need them).

> Arrive early on the day of your interview and smile a lot (it helps portray confidence, but more importantly helps you stay relaxed and be in control).

I almost liked the 'smiling' advice... But on the second thought, it's very much personality specific. In my opinion, some people appear less convincing when they smile a lot. Also, you need to realize that interview is a meeting of strangers, so the other side is somewhat nervous too, thus allowing yourself to be nervous is ok, no shame.

As always, the best advice is know yourself and be yourself. Managing a pretense requires extra effort, better direct that energy towards the challenges.

Interview requires some luck (there're always factors beyond your control). No matter what the outcome, I'd consider it a success, if I managed to stay true to self and learned something new about people on the other side...or myself.

Btw, 60 interviews in 30 days... Any offers extended/accepted?

>I'll add to the diversity on your team and _research_ has shown that diversity often makes for better, more successful teams.

For me it's a red flag.

Not only I don't think this is good when SE advertise himself with something like that, but also there are researches which show that diversity ain't that great as people seems to make it off.

> "Know your unique competencies and experience and present them in a way that matches the company’s needs without sacrificing your personality.

It is also important to understand the peculiarity of the company you are applying to and its specific needs. A startup or a smaller-sized company may have different needs from a bigger company, thus requiring a different skill-set."

This makes the case for targeted CV more than adding a cover letter to a one size fits all CV.

Fwiw, my first page / section is titled: Executive Summary. It's more bulleted but it could be sentences. The idea is to incorporate the concept of cover letter without having to worry it would be ignored.

That said, I'm going to try a cover letter. It might be enough to standout even if no one actually reads it.

> 3 virtual "site visit" interviews - 0% pass

I wonder if this can be chalked up to lack of sufficient practice for the virtual type of "site visit" interviews that lead to nerves, decrease in the all important self-confidence. Or perhaps it has to do with the always troubling you can't look at the people in the eye with a standard laptop embedded-top-of-the-screen webcam because it looks like you are not looking at them.

I would read another blog post from the OP just about their virtual "site visit" interview experiences.

I found his bit about recruiter in-mails peculiar, but I suppose everyone's mileage may vary. I almost never respond to in-mails, but I have these last two weeks for some reason. I ask for more information before accepting a call, sometimes they oblige, sometimes not. I haven't received a response though to any polite inquires I've sent them.

One thing I didn't see in this post was whether or not the author was aiming for a job or a roll at a specific company. While it makes total sense to get as much experience as possible, I expected to read more about strategically ordering the interviews such that you hit the ones you want later in the process.

The sheer volume is amazing. I think I’ve had less than one tenth that number of interviews in a fifteen year career!

It's pretty good written article, except that I feel a bit disappointed that he had to write in the cover letter "plase hire me Im black".

It sounds very unprofessional, but I could be wrong and that's a normal thing in the USA.

Another hint on timed coding challenges: most of them involve array or string manipulation, you can do these much faster if you learn how to do them via functional programming in your favourite language

For all the advice and sheer number of interviews he did in those 30 days, he never mentioned anywhere if he actually landed a job. Were those just for the luls?

For phone calls or video chats make sure your audio is decent.

Consider using something like nvidia rtx voice or rnnoise vst plugin.

Job hunting advice and I know this will get downvoted.

When called for an interview, ask as a first question why they think you are a good candidate for the job. It is clear by my resume and elaborated by my cover letter, but you would be surprised how many people are thrown off guard by this. Why? They got your resume from HR and never bothered to look at it. This saves time. For you and for the company.

Where's the data for the 60 interviews? I feel that this piece is nothing more than link bait without that data. That data could be anonymized, too.

>"With every unsuccessful application, I saw that something needed to change.

That change came when I took a break from meeting my daily numbers and began to think of my applications differently. I began to see each application as a sales pitch to the hiring manager or whoever was going to be reading my application, but here the product being sold was me."

[...]

>"Backed with my resume, this cover letter had a 95% success rate. The one time this didn’t work, the hiring manager still replied to let me know that the position was no longer available but he would like to connect in the future."

[...]

>"It is also important to understand the peculiarity of the company you are applying to and its specific needs. A startup or a smaller-sized company may have different needs from a bigger company, thus requiring a different skill-set."

[...]

>"But hey, you are also an excellent professional, and that means you never get on a phone call without knowing at least these two things:

the first name of your interviewer, and

at least one tangible thing about the company — what they do, where they are located, any recent news, something, anything!

I noticed that for interviews where I put in the effort to make these findings, I always came across as being genuinely interested in the company. That’s something recruiters typically look for in these kinds of interviews."

[...]

>"Good candidates know how to solve a problem (e.g. a sorting problem), but the best candidates know multiple solutions to a problem and understand the trade-offs of one solution versus the other.

The interviews where I performed the best (Cruise comes to mind) are the ones where I didn’t just solve the algorithmic challenge – I was also able to provide alternative solutions and discuss the trade-offs.

Aim to provide multiple solutions to a problem, be willing to discuss the trade-offs, and be able to implement at least one of them."

[...]

>"One of the companies I interviewed with provided hourly pay, about $68/hr, for the number of hours you worked on their take-home project — it’s that serious, so you should be serious about it."

PDS: It's actually not "that serious" <g>. That's because from the company's perspective, they are spending ONLY $68 or so -- to screen out bad applicants for a position that might pay $120,000 a year or more. Which is quite the COST SAVINGS (again, from their perspective) if the wrong candidates can be weeded out at that stage of the game. There is no business on the face of the planet which would not pay $68 to save $120,000, and if there is, then they aren't going to be in business very long! So is it "serious"? To you the applicant, from your perspective, it appears so, but from a purely business perspective, it looks like a tax-deductible $68 expenditure to potentially save $120,000 or more in the future.

In other words -- don't let things like this phase you.

You'll do infinitely better if you're relaxed, yet conscientious.

>"I had three virtual on-site interviews and I didn’t pass any of them. Sorry I’m not your guy for this one, but I’ve shared some resources that I think you may find helpful below."

You nail these ones via an "appeal to everyone" / "offer something to everyone" social vibe mixed with the tech. It's what politicians do, or what people do who arrive at parties where they don't know anyone, yet by the end of the evening, everyone winds up liking them. Why? Because they showed they can handle multiple people with different understandings and possibly competing interests. You didn't nail this one because this "skill" -- is purely a social skill(!), it's not tech related -- the greatest computer scientist with 10 Ph.D.'s, hundreds of papers and patents, and a Turing Award -- if he didn't have this social skill -- would also have been rejected, so don't feel bad!

Now, on a different note, I wanted to add the following comment/suggestion to your great article:

Historically I have had a 2:1 ratio of of tech job interview : job offer.

In other words, historically, half of all of the companies that I have interviewed at, wanted to hire me after the interview.

One time, to understand this phenomena better, after being offered a job, I asked the interviewer,

"If you don't mind me asking, exactly why did you want to hire me?".

His answer was absolute pure common sense.

He said to me:

"All of the people that we interviewed told us everything that we would have to do for them.

You, on the other hand, told us everything that you would be willing to do for us."

You see?

180 degrees reversed...

And absolutely pure common sense...

Anyway, great article!

> "Since your interviewer is a friend, a buddy, a team member who’s on your side and means well for you (Refer to 4), talk to them while you're figuring it out."

I strongly disagree with this. It is true in theory but doesn't work in practice. Most FAANG interviewers are looking for a fast optimal solution. Unless you are interviewing for very junior role, if you take hints from interviewer, it'll likely go against you.