I’ve used Project Eulers Problem 001 as an interview filter and more than one senior developer failed it… not surprised they don’t know what a map is too
They built an interpreted language in C over a summer, I think they are beyond “getting into programming” - they’ve clearly been programming for years.
If it helps I would absolutely struggle to do this as a dev with 9 years experience. You’ll never totally shake imposter syndrome in a field where you can easily see such excellent projects routinely.
Hasn’t hurt me from finding interesting jobs that pay well!