The first interview was probably the hardest interview I have ever been through. You could literally taste the beads of sweat roll down my forehead. The first interviewer was the technical director who told me I failed my online coding test because my algorithm was O(n^2) and too slow. The second panel included two senior developers who asked me to write more code and design an additional algorithm using terminology I have never heard of before. The one senior developer explained their core technology in terms of calculus, which I felt very comfortable with being one of those coders who loves math too.