Ask HN: A coding test or working for free?

It's the future. Crowdsourcing through job candidates.

I had a similar experience with a company in Berlin, Germany. They didn't care about the code or my skills. Only if the submitted solution worked against their existing tests.

I think it's just a sleazy way of getting things built for free. Basically, write only a test for the functionality you want. And give the actual task to job candidates. If someone succeeds, you have both the algorithm and its test for pennies. It's based on P = NP. Testing the result is easy. Designing a solution is the hard part.

I now refuse both technical interviews and take at home tests. Limits my choices a lot. But the ones that remain are usually top shelf.

Wait, you refuse technical interviews and you say the rest are top shelf? I'm curious to know what your ideal interview looks like. Or do you mean you just get hired through networking?

I've had a very similar experience to this commenter. I wouldn't say that I reject all technical interviews and take home tests, but I certainly reject a lot of them and find that I have little trouble finding really high quality companies that will speak with me. As you say, a lot of it comes through broad and deep networking. I know people, I have a proven track record in business and technology, and people are comfortable working with me.

An ideal interview is one where I get to learn as much about who I will be working with and what I will be doing as they will be learning about me. Generally these turn into more discussion based interviews where we talk about the issues the company is having and how I might be able to best solve them. They still get a good idea about how I think and work by discussing the problem back and forth. I also get to see how they think and work.

Frankly, I white board problems very well. But when companies ask me to do so in an interview I want to see them do it as well. I want to see their ability to code as much as they want to see mine. Same goes for a take home test. If we are going to work together and you have to see code of mine, I very much want to see yours to make sure it is up to my standards.

Is it possible the German company was trying to see how you react to failing tests?

I just ask because it seems like trying to get work done for free through code exercises is much more trouble than it's worth.

You would stand a good chance of waiting a lot longer to get that work done, but as mrcold said, testing a solution doesn't cost much. If you're willing to wait for the solution to a problem, getting work done through code exercises can be worth it.

Yea, I guess I was thinking more that it would take a lot of time to unnaturally break down a problem into portions small enough to pass as code exercises.

After having been asked this several times, I've begun to make it clear that I will only engage in these tests if I'm compensated for the time. It's a delicate thing to do, really, telling someone that, no, you're not going to work for free, just on the hope that you might get a job.

But it doesn't only happen in this industry: my niece is a graphic designer & has been asked to provide samples of her work on projects ... to the interviewer's specification. She's done it, because she really needed the work, but felt terribly taken advantage of, and I'd agree: it's predatory.

I have the luxury of telling people that, no, I won't take their 1) IQ test, 2) Personality Test, or 3) their Coding Challenges. Not everybody does, certainly.

The appropriate thing to do is to either state up front that you'd need to be compensated for your time, or acknowledge that you're giving away work as a way to possibly get in the door & just write the best solution you can write - not leaving it incomplete, necessarily, either, as that is a sort-of halfway position that makes you look bad.

>>> I have the luxury of telling people that, no, I won't take their 1) IQ test, 2) Personality Test, or 3) their Coding Challenges. Not everybody does, certainly.

I agree with this 100% and do the same thing.

If you need something that measures my ability, then go to my github page and go over the copious amounts of projects I have there and determine if my skill level is what you need for your company.

I had one interview where I had sent over a link to my github page. As soon as I sat down, I was given a large packet (it was about 20 pages) and asked to look at the code and figure out the bugs. Most of these were in Java and .Net. I reiterated I didn't work with either language and they told me to "just look at the examples and give it a try." I asked them if they had looked at my github page and reminded them I'm a front end developer. After they said, "Uhhh no, we didn't look at your examples." I stood up and told them, "Thank you gentlemen, but this interview is over. Thanks for wasting my time." and walked out.

I've also turned down "code challenges" that would eat up a week or so of my time. I've got a myriad of recruiters calling me for gigs, why would I waste a week working for free on your "code challenge"? I guess I'm at a point in my career where my work can speak for itself. I don't need to jump through a bunch of hoops to prove my abilities anymore.

Hm.. how about some kind of three-way cooperation, where you get non-profits and charities to give specifications for work they need done, which can then be used for interview samples for actual industry jobs.

The candidate can demonstrate their work and be assured that neither does the company extort free labour from them nor is the work they do for the bin, whereas the companies can see how they behave in real-world environments.

That sounds amazing. I would love to contribute to such a project (or be interviewed using one).

(Actually, would you mind if I stole this idea?)

Feel free! (let me know if you ever build something, maybe) :)

Did anybody start on this or plan to soon? If not, I'll start it and make it open source. It's a killer idea. :D

Not yet; I'm travelling at the moment but should have time this weekend. My email is jonathan AT jeskew DOT net if you'd be interested in collaborating.

I had a similar idea a while back... I would also be thrilled if you stole it :)

Tell numbers 1-3 to Google and you'll find the door.

Principles and self respect have real costs. The milieu right now is a race to the bottom, and refusing to be a part of it might get you left behind.

This is further evidence of the need for unions to make a comeback.

But wait...you're saying...if I don't race to the bottom, I might not end up there along with everyone else? :)

Pretty much, but you get to maintain your self-respect.

Self respect can't feed you, but it's not so bad.

Curious. What is your objection to the personality tests? I took one for a new job once, and I felt uneasy about it, but can't really articulate why.

I don't know what one you took, but the one I was told to take (and vociferously declined) was somebody's unscientific hack of the MMBI. You know, the test that tests for mental illness. No one's business. Sorry, you don't get to know how many friends I have (a question), if I have nagging doubts (a question), and so on. It doesn't matter if those are problem spots for me or not, it is the principle.

Also, that HR person is not a trained doctor. They have no business administering any kind of test of this type, and certainly have no business trying to interpret the results. It is just woo nonsense. Might as well try to do handwriting analysis, or read my tea leaves.

You are not allowed (in the states) to ask interview questions about health. Yet, somehow, the courts have found these 'personality' tests legal. I don't understand, but I will not participate. I don't take drugs, but I won't take a pee test either.*

* these results might vary depending on how close I am to foreclosure and how low my saving are. Principles are costly.

Completeness is subjective here, but I understand where you're coming from.

That smells a bit fishy. I think you've dodged a bullet.

I have to be a bit cautious here, because our company does something similar.

We have a little programming challenge that we ask candidates to submit. We don't use those submissions in production. We find it gives people with non-traditional backgrounds a chance to show their chops, and gives us some meat to discuss during an interview.

The challenge probably takes 4-8 hours, though. Part of me does think it's a little asymmetric for us as employers to be demanding this of candidates. We've also done week-long work tests, where we pay the person market rate to work with us on real-life code.

Anecdotally, people view the paid week-long trial as demeaning, but the (unpaid) challenge as exciting and fun. We live in a bizarre world.

> Anecdotally, people view the paid week-long trial as demeaning, but the (unpaid) challenge as exciting and fun. We live in a bizarre world.

That's because it is demeaning. It represents a large chunk of someone's life invested in proving that they're good enough for you. It's also inherently asymmetric in that the company you work for could not possibly be economically harmed by a week-long trial period, but a single person could be financially devastated by it. Additionally, if the person discovers an illness during that period, do you provide health insurance? What about employees coming from other employers? Do they have to quit their prior jobs or use up vacation time to complete your "interview" process?

A four or eight hour programming exercise skirts some really stupid aspects of interviews and the hiring process. Of course that's welcome. A week-long commitment to work is a sizable tenure as a second-class citizen undergoing prolonged scrutiny.

Your company should be deeply ashamed of this practice.

Perhaps I wasn't clear, the trial is an alternative path to employment if, for whatever reason, the challenge + interview isn't suitable.

If you're on the fence about us, give it a shot. If we're on the fence about you, your option is no offer or a week-long trial. As I identified elsewhere, a drawback of the trial is it's mostly only useful for people who are unemployed.

> Additionally, if the person discovers an illness during that period, do you provide health insurance?

We live in a country with reasonable health care coverage, so this isn't really a thing.

> A week-long commitment to work is a sizable tenure as a second-class citizen undergoing prolonged scrutiny.

This is my knee-jerk opinion, too. However, what is the alternative? We could hire you full-time right out of the gate...but we could still fire you after a week.

> Your company should be deeply ashamed of this practice.

Deeply ashamed might be overstating it. Contemplative and reflective, perhaps.

Perhaps you missed the part about paying normal rates for the person during that week?

If I'm looking for a job so desperately that I'd be financially devastated by a lost week, then I'd surely jump at a paid week of work, no?

You're not considering the situation where the candidate has a job already but is looking for a new one. Quitting your current job is a large commitment, and doing so for only a week trial period (where the odds are higher you'll be unemployed afterwords) is a pretty large risk.

That being said, for someone who is currently unemployed, putting job interviews on hold for a week is less of a risk

Ah, indeed, I did not think of that. There'd be vacation days to avoid having to quit your current job for that week. Still, there's other problems, like maybe the contract forbidding you to have other jobs unless cleared by your employer, and taxes because you suddenly have two jobs – not worth the hassle for a single week, I guess.

Spending half your annual vacation allotment on one job interview. Who would do that?

"The challenge probably takes 4-8 hours, though."

The problem with that is you aren't the only one doing this and when I am job searching I am applying to many companies. So now I have 10 different companies asking for an 8 hour code test to be completed within a couple business days. Meanwhile I still have a job to hold down. It's a massive time commitment to make to just one company without knowing if the work put in will result in an offer.

I much rather prefer companies that aren't lazy interviewing and will look over some of my github repos and discuss those with me to gauge my experience. There is no one size fits all answer to interviewing, but 4-8 hour code tests(plus interviews) just isn't one I can get on board with.

Here's my problem with pre-interview coding tests:

1. The employer is just sending the coding test as a form letter to everyone who submits a resume. I can submit the test, ace it, THEN they read my resume and decide I'm a bad fit. So I wasted my time.

I've done several coding tests where I know I aced it, and still no interview. Why am I wasting my time on this?

2. I do the test, get an interview, and now they decide I'm a "bad cultural fit".

If you're going to reject me for a flaky reason like "bad cultural fit", then you should do it BEFORE you make me waste time on a pre-interview screening test.

But as you said, the test is a useful way to filter out bad employers. If they ask me for a coding test, I don't do it, knowing I'm not missing much.

Suppose there are 5 people willing to proceed directly to a phone interview and 20 people who want me to take a 1-8 hour coding test first. As a candidate, who am I going to spend my limited job search time on?

We don't have a time limit on our challenge - it's public, you can work on it whenever and submit it whenever.

But I do see how having a challenge means our funnel gets narrower at the top because we're competing for people's time. We think we're worth it. :)

At the same time, we're always wondering if our process is excluding too many people. If someone came to us and articulated: "I think your challenge is trying to assess me for X, Y and Z; here's a GitHub profile that shows I have those traits" we'd likely be open to being convinced.

Obviously anyone really good won't actually do the tests because they'll be offered a job by somewhere that doesn't do them before they get around to yours though, sooo...

Personally I find the single best question is "what's your github username?". People who are on it and active are... well, actually I've only ever had one candidate who's actually been on github and she seemed OK. The majority of people I've seen haven't been much good (and have barely heard of github).

I agree about dodging a bullet. I think the OP did exactly the right thing.

I have seen this first hand. Company A told me to complete a programming test, and only then they would talk to me further. Meanwhile, Company B gave me a solid job offer and I never got back to Company A.

I don't feel too bad about ditching Company A, because they have contacted me through recruiters a few times. It's always the same story. I complete their programming challenge (which is really easy, because it's always the same), submit it, then never hear anything back, not even an acknowledgement that they received my solution.

I'm curious, how does companies usually evaluate a github profile? and how important is that evaluation to the decision?

I ask this because I find many of the software engineers I follow on Twitter who work at major tech companies (github, twitter, google, etc) have a pretty sparse github profile.

I started asking it really so I could see examples of a candidate's code. Also seeing the projects they've contributed to would show that, for example, they genuinely were interested/engaged with whatever niche they were being interviewing for.

A problem with github could be that a lot of the code you write needs to be kept private for commercial reasons, and then I guess some kind of coding test would be better

We'll definitely consider a GitHub account as well, but we don't want to exclude the universe of programmers who are Just Busy Doing Their Dayjob And Having a Life and don't have time to maintain a ton of open source forks.

Yeah there are definitely degrees of "active", but even one or two forks, or even submitting an issue to an active project demonstrate engagement that says a lot about someone.

But is the opposite true? If someone hasn't contributed to an open source project, does that say a lot about them?

What we've found is that the best folks want a (paid) trial - not because they want us to trial them, but because they want to trial us. Works out for everyone.

That's a good insight. We should make sure we frame the trial the right way so both sides see the benefit of it.

One big downside of trials is they exclude people who are already employed...ah well, can't win 'em all.

Eh, the job market is already grossly skewed in favor of the employers. Asking for 4-8 hours of unpaid work is probably fine though, given that an interview would take about that long... assuming the interview itself will be very short, that is.

We have 9 interview loops spaced out over 2 months.

Just kidding, the interview itself is very short.

Honest question: is tricking coders into doing work for free a thing that actually happens? I'm not saying it doesn't, I've just never heard of it.

From their end, if that was a thing they regularly did, it would be such a hassle. After all, you'd have to find a new person to do that work every time, find a way to split up the work into very small chunks, and who knows if the result from a person off the street would be usable?

My guess would be that he was trying to evaluate how you respond to bug fixes and criticism. (Still sounds like a weird interview strategy though)

Most companies that do this (unintentionally, I believe) are not benefiting from the actual work product, but from the consulting regarding their business problems.

How much do you think a consultant would charge to come in for a few hours and discuss their needs, not to mention put some working code together for their problem?

This is a valid point. I agree it doesn't seem like an efficient way of conducting a business in the long-term, but for a one-off problem that they happen to be stuck on, it makes more sense.

The feeling I got was that they weren't developers by trade (the code quality I mentioned was a red flag), very small, early-stage startup with no money and they needed expert help, fast.

Most of the time I faced only absurd coding challenges that yielded stuff the companies couldn't use for anything.

I still paid it with my time.

Something similar happened to me, but I was never provided with the "programming test".

My interview for a freelance gig was wrapping up, and the COO asked if I would be willing to "fix a few bugs in the system" to see if I were a "good fit" for the project. I asked point blank if they were asking me to do work for free. He responded that no, he was not, and that the task would take no more than 30 minutes to an hour. I said that I would be happy to take a programming test, or provide some other proof of competency, but that it's pretty non-standard to ask me to fix bugs in a system for free, especially for a limited hour freelance gig.

Up until that point, we were discussing project time lines, handing over of logins, and my number of hours of availability. I got an email the next day saying that they were going to go another direction. Likely, trying to fund some other suckers to fix their bugs for free.

I haven't run into this on the interviewee end, but my company has applicants work on real projects, and here's how we deal with it:

Pay them.

This is a simple solution to the problem. Paying someone for an hour or two is absolutely nothing for a healthy company.

So if the company wants to have you write code to prove your mettle, have them pay you for the time.

Except you cannot do that in every country. You know, Labour right.

Well, in case labour laws prevent people being paid for some labour -- or if the applicant needs to be registered as an independent contractor in order to receive payment for the work -- can't the company just pay for the expenses (and a little extra) and thus compensate the applicant sufficiently? It should be possible to pay for travel, stay, lunch or other 'inconveniences' in case the labour/deliverables can't be paid for directly, right?

I'm not sure I understand. Care to elaborate? Pointers?

In my country the potential employee would have to be registered as an independent contractor before being able to charge for the provided service. And then if he wanted to become a full time employee he'd have to unregister as a contractor.

Yes. In some countries, laws are strongly in favor of employee protection (for a good reason).

That's the case here. One employer could severely abuse paying candidates for some quick job without any contract being even mentioned between the 2.

This rules out all manner of great employees. Basically all of them that have a job currently and have read their employment agreement.

In most places it is standard boilerplate that your employer gets approval rights on any outside work you do while employed by them. Current employees also have more restricted IP agreements typically which can put the contracting company in legal trouble as well.

For this reason, I've found paid real work projects problematic in that it biases against the currently employed.

Seems like the obvious solution. I know Automattic (makers of Wordpress, among other things) does that.

I was recently applying for work after graduation. One entry level position and a small company (with a vague job posting) wanted me to complete a pretty extensive problem which would involve access to their code base and take "5 to 10 hours." I also would need to use a Mac and Objective C, even though these were not on my resume or the job posting. (I work in a .NET shop and had mentioned using Xamarin for Android development, and they were mainly doing iOS and OS X work, but extending into being cross platform).

I asked if they had a problem I could do that would be on more familiar tooling, noting that even if I could borrow an OS X machine, it would take me a while to get familiar enough to complete the task they sent me. I also expressed concern at the length. I ended up declining to participate and they moved on.

(Note: I have never used OS X besides briefly using someone else's computer. Everything I have used has been Windows and Linux, with a couple of weekends of trying some BSD-based distros thrown in.

Did he even ask you to describe how you would likely tackle the problem while you were in their office? Things like design ideas, architectures, technologies, pros and cons, etc?

If all he did was ask you to "do this" at their office without picking your brains as to your thought process, then regardless of the legitimacy of the offer, I would think twice about working there.

The fact that he's asking for a solution that works on all of the data rather than a sample of it is also highly suspect. Either he is not being frank with you, or he doesn't have a firm grasp of scope (most likely the latter). Either way, he's probably not the sort of person you'd want to work for.

I went through a couple of cases with him where a regular expression wouldn't work, how I might test my solutions, pros and cons of my proposed solutions, how it could scale in the future, etc.

That conversation was there. After we spoke he left me to work.

Why don't you post your sample code on github? Maybe the CTO just wanted free work from you, but maybe he just wanted a candidate that was able to complete the assignment. He could have thought that you cherry-picked the easy cases and were unable to solve the tougher ones.

Coding tests unfortunately aren't just about demonstrating skill. Then people like me could just link to their github QED. It's also about completing assignments and doing stuff because you are being instructed to.

Maybe the CTO should post his database on Github. If he wants the test code to function under certain conditions, he needs to publish those exact conditions. Not specifications, but the actual data that the test will be run against.

If he's not comfortable doing that because it's restricted intellectual property, I might wonder what the real purpose of the test was.

Any programming test that takes over an hour to complete is highly suspect. If it took less than that to complete the code (you did not specify), then IMHO I can understand why they were expecting a more complete answer.

Regardless, my hunch is that your instincts are right about this one.

I don't agree about the hour. I've done a programming test that took way more time (partially because it involved learning an entirely new framework). It was at a company where everybody gets the same test (and everybody solves it in a different way), and then presents their code to the assembled programmers of the company.

I still think that is the best way to interview (after a regular interview to weed out the real idiots).

I think the real thing that's suspect, is simply having to send in your code, rather than presenting your solution to a group of programmers.

I disagree. I think coding tests are a great way to judge candidates. But only if they are given proper weight. Nothing worse than submitting and acing a big coding challenge and then being told they don't think you're a good culture fit. Some companies employ such hiring practices and I think it is very unethical.

That's why I've soured on coding tests. After lots of employers didn't give me an interview after a coding test that a KNOW I aced, that's poisoned the well for me.

Now if someone gives me a pre-interview coding test, I mentally translate it to the employer saying "I don't respect your time."

Same here. I've been through the same song and dance. If something happens over and over and it results in my not getting an interview, much less the job, I'm not going to repeat it. Especially if it's time consuming.

If the company asks for a coding test, I politely decline, but I offer to provide them with a code sample instead. Very rarely has that not resulted in a phone interview and I didn't have to spend hours of my time on it[0].

[0]: per company. Write once, give to many scales better than coding tests.

Thanks for the feedback.

It took several hours. After an hour of examination of the data and research into the problem at their office I opted to make it a 'take home' test. They agreed and I worked on it the next day (hence the e-mail conversation).

If they're running your code against actual production data, that crosses the line into questionable territory.

I've been given programming tests before, but they were always for hypothetical problems that were open-ended. That way, each candidate solved the problem in a different way which was when discussed during the interview process. In your case, it sounds like they wanted you to solve a specific real world problem they are dealing with.

Am I to understand from your explanation that they asked you to solve a real business problem with real business data as an unpaid "coding test"?

If so, I'd say they were clearly in the (legal) wrong even before asking for the refined version.

I had an interview at a company once which was basically pair programming with a few different engineers for a full day on real code written for real clients. The best part was the NDA they asked me to sign 6 months later.

It's probably not a good idea to post the name and title of the person you spoke with when it's a small company.

True. OP could have asked for advice without naming names.

Let me argue in favor of coding problems. Unpaid coding problems have a couple of very appealing properties:

1) They are available to all applicants (not all applicants have github profiles, or can show previous work samples, or are available for short term contracting work).

2) They do not cause problems with typical IP agreements or extra curricular work restrictions.

3) They can be standardized so all candidates receive the same process.

4) They are a closer proxy to the "real work" of development jobs than many other alternatives (and there is lots of research that indicates this leads to better results).

Those properties are very important and cannot be found in hardly any other style of hiring filter. For this reason, its my belief that coding problems are central to a good hiring pipeline. I believe this so much that I'm willing to replace nearly every other part of the hiring pipeline with just the programming challenge (though that is a hard sell with management often).

The problem with coding problems is that it is very hard to come up with good ones. They should take less than 4 hours to solve (everyone severely underestimates how long their challenges are), they should be indicative of the kind of work you will you do, and they should be, if not fun, engaging. So normally when I encounter bad programming problems I chalk it up to that instead of malice.

It is everyones decision to not do programming challenges of course, and I completely understand people who will not do them. But to me the standardized hiring pipeline is the most important part and I'm willing to lose a few good candidates to get it. For this reason, I view a programming challenge as a good sign for a potential employer, and the lack of one to be a serious red flag.

If someone is using a coding challenge to get free work, that is at the least unethical and likely against the law depending on your jurisdiction.

I interviewed at a rather fast growing startup in SF (hear about it here on hn pretty often).

The interview was simply 'sit on that corner and fix this bug'. I said I don't work for free, so they said 'oh sure, we'll pay for that!'. Finished the bug fix, expecting a follow-up review or anything, so their CTO responded with 'oh, that was too fast. Hm, let me get you another bug.'. At that point I realised their git log must have at least a hundred different names on it.

I politely refused and said if there wasn't no interview, I'd just leave. They gave me a check and that was that.

One week later, the CEO emails me saying they'd love to hire me, but I'd have to quit my job first and they'd evaluate my case after 2 months with them (I was an h1b at the time).

'No thanks.'

I wonder about the copyright of such a thing. If you aren't an empployee and don't sign over rights, are they even allowed use it?

This is like asking a carpenter to prove their skills by building you a deck, in a day, for free. Good luck. Any work performed should be paid, period.

Diplomatically for Joe's sake: your standards of professionalism do not align with Joe's vision of company culture. Apparently, someone has mistaken cost-savings for a core company product line.

Good luck.

I have done at home prescreener tasks, as long as they were sub one hour, clearly academic, and patently not related to the business. These are not paid. I have also done on-site dev tasks and tests which were squarely related to the core business, and have invoiced my day rate each time, which was paid. If a company asks for more than an hour, for tasks related to their business, and don't want to pay, run, don't walk away, and better still, spread the word so people become aware and avoid them in the future.

Shady code test or not, I don't agree with the manner in which you handled the situation. You agreed to do the test, submitted it partially completed, and then replied that it should be sufficient (knowing full well you didn't meet the requirements). I doubt the CTO didn't understand that the other cases would be trivial to implement; he simply sees a half-finished submission and a candidate who didn't correct the mistake when given the chance. Had this been a college exam and not a code test, would you expect a professor to award you a passing grade based on the entirety of the test, or the questions you chose to answer?

One thing to keep in mind is that while you may view the code test as bad, it might not having malicious intent; some managers simply lack experience in putting together tests and fall back on old specs. There's two things I do during interviews prior to writing a single line of code:

1. Every code test I have taken has been brought up during a discussion. I use this opportunity to ask questions about the test. If you're interviewing with a recruiter who's not familiar with the test, they'll forward your questions to the manager who's evaluating the test for clarification. The manager's response will come either prior to accepting the assignment, or with the assignment attached to it.

2. Immediately upon receiving the code test, I review the spec in its entirety. If I have concerns with the spec, I raise those right away, as to not give the impression that I'm incapable of completing the spec if I bring up these concerns at a later time.

I remember the guy who asked me, as a coding test, to write a program that connected to Interactive Brokers and executed VWAP trades.

He got very angry when I offered to do it as a paid consulting project. If I did it for free, he wouldn't need to hire me at all!

It has to be a throw-away scenario and a throw-away code. Anything else is wildly unethical.

I think this is why problems that feature singly-linked lists are so popular: you can tell from the start that the problem is limited in scope and has nothing to do with any system currently in production.

Indeed.

On the other hand the interviewing company should avoid such situations too because of the information secrecy - unless they are mandating an NDA with each and every candidate.

It sounds like a miscommunication between you two, nothing more than that.

I would view this as a blessing though. For me, interviews are a chance to evaluate how well we can communicate. If I can't be relaxed, make jokes and just feel free to talk, then I won't feel that way working for you during the next year, and that to me, is a no go.

I'd say indirectly you dodged a bullet, sounds like you two might be a high risk for constant miscommunication.

I have seen a lot of such cases as well, always the best is not to accept it in the first place and offer giving a test on an open source project for example.

You working on a commercial project means that they can implement your solution and get money from it, so it'd be fair that you'd be compensated for your work.

I'd ask to be paid for the amount of work that I'd be doing on this project or the option to get my skills assessed on some other, non-commercial test project that they wouldn't benefit from.

When I interview candidate I make them fix a problem in our real system. First by just talking it out (interview, unpaid) then I have them build it. Or what they can build in the time allotted. I pay for this time. Its basically hiring through short interview then real work on 1099style. Interviews you should do for free but fixing my real problems I pay for. I can decide who to hire with less time invested and know more about my new hire. #winning. Built a web-service/ATS to help me manage the while things

Don't bother continuing the interview. An employer should be more considerate of the interviewee's time. Imagine you worked for this person?