Just a few comments I left on this blog post, maybe someone here will also find interesting or useful:

I'm sorry, but I must respectfully disagree on a number of points. I think you make a number of flawed assumptions and miss some great opportunities when you pass up an interview that allows you to work in their code base.

1) Maybe this company was different, but as for me if I bring in an interviewee and say "Let's pair on some code for a day, and try to release a feature" I know up front this will be an up hill battle. Can you really say that you, an interviewee who has never seen the code base, will suddenly make amazing production grade code? I am absolutely sure that if I were to grab one of my other engineers, seasoned in my code base, I would get this task done in half the time. The point is, I am assessing you to see how you work with me, what your attitude is while we pair, what your contribution to the process is, and to a lesser extent how your code looks. Can I get this out of an open source project enhancement, maybe. But I can certainly get this out of my code base and it will cost me more than it will cost you in income.

2) You've missed the opportunity to look at my code base for a day. I can't name the number of times where I have walked into a company after a lovely interview experience and said to myself "I wish I had seen their code base, this is horrible". Your other blog post states you want to "test the company" before you take a job. Test them.

3) I won't discuss how low your day rate is, and how it establishes that you are an inexpensive engineer (that may have been what you were trying to get across) but I will discuss investment in future earnings. In my last few jobs I have received at least a 5 figure signing bonus, and generally a healthy pay raise (this is generally why I move companies). When I sit down to pair for an interview "for free" I don't think of it that way. I think of this as an investment into my future earnings. I am going to get a signing bonus from this "trendy startup, complete with ping pong table". I am going to get a healthy pay raise. It will equal far more than my day rate. You might say "But what if you have to do 5 or 10 of these interviews with companies before you get a job?" I often do! Getting a job is a numbers game. But I am still highly compensated for my time, just not right that moment. It is ok to defer payment. Investments can be quite rewarding. (Not to mention, money isn't everything. There are other reasons you may want to leave to another company. Account for that in your equation). If I interview with 10 companies and they all have me working on their code base, I hope they enjoy the one day of free work. I won't get paid by all of them. But I will not lose a dime of my own income in the end. I will make it back when one of those 10 companies hires me.

I understand from this blog that you would rather not be tested and that you would rather not work on a companies code base. But a company that wants to hire you, wants to hand you a pile of cash and a hefty salary and benefits, needs to assess you somehow. You also need to assess them. I think a day of pairing on their code base can easily tell you if you are a fit for them and they are a fit for you. In the case of this interview, maybe they very quickly figured out you are not for them.