The actual amount he has made is not impressive, but starting from nothing is impressive.
Through word of mouth, and repeat business he will be able reduce the time required to acquire more work. He can use the skills he has acquired to be more productive and valuable to future customers. New clients and repeat clients will also be willing to pay-up since he is now a trusted resource, with less risk.
There are some problems with the trial period. It doesn't account for those that don't have specific domain knowledge. From my experience, I have worked with people that have hit the ground running and been really productive straight away, but in the long run have not been as innovative as others.
I prefer to hire a candidate that might take 2-3 months to get productive but have some really innovative ideas, that others in the company might have missed. Puzzle questions do give me a sense of how someone approaches and solves problems, and I think you can infer how they will handle real problems since the building blocks to problem solving are essentially the same regardless of what domain. Solving puzzle questions is just a component of things I look for:
1. Experience in solving challenging problems
2. Good university results
3. Personality fit, easy to get along with
4. Leadership potential
5. Enthusiastic/passionate
Not all five are needed, but candidates need to be strong in more than 1-2 areas.
If you have issues with interviews specifically, you could enter a TopCoder competition, or Google Code Jam, and use that as evidence that you can solve those types of problems.
I perform much better at interviews when I am relaxed. If you put too much pressure on yourself, then you will not be relaxed and will perform badly.
If you do a perfect simulation of an interview at home do you perform well? Find an interview question you haven't seen before, and attempt it exactly like you would at an interview. Have a software developer friend mock interview you.
If you feel like you perform better in a simulation, you may consider seeing a psychologist or reading some books on the subject. I once went to a workshop on how to deal with high pressure situations, and many of the exercises suggested made a difference to my interviewing.
The tips in the following article I feel apply equally to interviewing. I suffer the mentioned symptoms during interviews. When adrenaline levels are high the brain will enable a short-cut mechanism that allows you to make quicker decisions, but often not correct when considering a difficult question. The dreaded "tunnel vision" is a fight/flight response.
Admittedly I don't have that much experience in Java but have worked on C++ systems with sub 10us latency (and it did fairly complex things). Any memory allocation can take an order of magnitude more time than that.
Apart from writing your own memory arena, you would need to put local objects on the heap in Java. It is possible to write high performance Java, but like a previous comment mentioned, that code looks more and more like C++, so why not just write C++?
Nice find. I would say people that I have interacted with most recently. I saw someone in my list, close to the top, that I haven't interacted with for a long time, but they would be interested in links I have shared, so could be incorporating views along with other things.
Could be possible to reverse engineer this list with some fake profiles.
This is the Tesla of bicycles: http://www.faradaybikes.com/
Currently selling for $3500, I would buy the Faraday if it sold for around $1000-$1500.