I agree with the recommendation here to read Expert C Programming: Deep C Secrets by Peter Van der Linden. As for practice: the challenge in learning new tech

I agree with the recommendation here to read Expert C Programming: Deep C Secrets by Peter Van der Linden. As for practice: the challenge in learning new tech is always to find a small-scale project that motivates you to build something. As a mostly-Rails developer like you I've found a couple opportunities to write C by building Postgres extensions. Here are my two: https://github.com/pjungwir/aggs_for_arrays/ https://github.com/pjungwir/aggs_for_arrays/ https://github.com/pjungwir/inetrange https://github.com/pjungwir/inetrange Both of those are used in production systems and had good justification for dropping down to C. Or here is a tiny patch to the Postgres btree_gist extension that I am hoping to get merged: https://commitfest.postgresql.org/10/332/ https://commitfest.postgresql.org/10/332/ The JSON support in Postgres is still pretty new. Maybe you could write some worthwhile additions for dealing with json or jsonb data? I would just look at underscore.js for inspiration. Also if you have a collection of personal shell utilities, you could try rewriting them in C. Here is one of mine: https://github.com/pjungwir/range https://github.com/pjungwir/range It is for printing a range of numbers like `1, 2, 3`. It is surprising how many features you can add to a tool like that! (It is a bit of a joke, and I have since learned bash gives you `{1..10}`. But something similar could still make a good learning project.) Perhaps you could also write a ruby gem that wraps some C library. For instance I'm fond of the jsmn JSON parser [1]. Maybe a gem built around that could give performance benefits? Or maybe some way to easily use Protocol Buffers instead of JSON for Rails web requests? [1] http://zserge.com/jsmn.html http://zserge.com/jsmn.html