When I recall my STL interviews on Wall St, it’s clear that majority of c++ app developers use STL almost like a black box, every year for 5-10 years. Only 1% has the level of insight as Henry Wu.
Reason? such insight is never needed on the job. This factor also explains my advantage in QQ interviews.
- Analogy — Most of us live in a house without civil engineering insight.
STL uses many TMP and memory techniques. Some may say STL is simple but I doubt they have even scratched surface on any of the advanced topics.
- Analogy — some may say VWAP execution algo is simple.
Many interview questions drill in on one or two essential STL functionality (which everyone would have used), just below the surface. These questions filter out majority of candidates. Therein I see an opportunity — You can pick one or two topics you like, and grow an edge and a halo, just as Henry did. Intellectual curiosity vs intellectual laziness. 不求甚解，不加咀嚼，囫囵吞枣 — I see it in many self-taught developers. That’s exactly what these Wall St interview questions are designed to identify and screen out.
How about west coast and other high-end tech interviews? I’m not sure.
 sometimes 90%, sometimes 60%.