How to Hire a Programmer
As much as people like to deride #1 (here and elsewhere) it's one of the most useful filters (in terms of filter value for effort spent). It's not a positive filter (in that a candidate who passes won't necessarily be a great programmer) but it is a great negative filter (a candidate who fails almost certainly isn't).#2 I have mixed feelings about. A lot of people work on things where the source code (even the product) isn't visible. Having an SO profile is semi-useful but lack of one doesn't really mean anything. Github only makes sense if you work on open source (and frankly I'm tired of the incredibly naive "Github is the new CV" postings that pop up every few weeks).#5 is what I really object to. At least in this case you've gone through the initial filters. Some companies use an audition project as an initial filter before you've ever spoken to anyone (you know, to see if you'd be a cultural fit and so on). I have zero time for this.The problem with an audition project is that anyone truly good won't have to jump through those kinds of hoops. They'll have their pick of offers as is. Job seeking through a traditional (non-network) route is relatively low percentage such that there's only so much time worth investing in any particular position.I'm happy to prove to you know I have a solid enough foundation in data structures and algorithms, I can program my way out of a paper bag and I can problem solve and communicate effectively but as soon as you ask me to spend a week--even a day--on some audition project, forget it.Honestly, hiring isn't that hard. You just need people who are good at hiring to do it. I've done 10 or so "lunch interviews" at Google this year. This isn't an interview per se. It's simply taking someone to lunch in between their onsite interviews. It's a chance for the candidate to unwind, ask some questions, etc. But there is no feedback element to the process.Of the 10 after 10 minutes I predicted 8 wouldn't get hired, 1 would and 1 I wasn't sure about. Turns out the "yes" declined an offer and the "maybe" didn't get one and I was otherwise right. And this is simply from going to lunch with them.My formula is:1. Filter early. "Hello world" and other simple programming tests;2. Establish technical foundation and problem-solving ability  (with one algorithm-related question that should be coded); and3. Otherwise ascertaining personality/cultural fit. This you should get just from talking to someone for 10-15 minutes.It's really not that hard. You just need someone who can actually do it to do it.