I had a pleasure working with Andrey Michailovich Smirnov when I was around 36 in 2007. He was 75 at the time and was definitely run circles around me. For exam

I had a pleasure working with Andrey Michailovich Smirnov when I was around 36 in 2007. He was 75 at the time and was definitely run circles around me. For example, he was able to produce working compiler for subset of Fortran with compilation into dynamic dataflow machine in two-three weeks. I don't think he was retired.