Auth
Video: An Illustrated Guide to OAuth and OpenID Connect
The Simplest Guide To OAuth 2.0
Diagrams And Movies Of All The OAuth 2.0 Flows
Diagrams of All The OpenID Connect Flows
OAuth2 and OpenID Connect Essentials for Web Developers (Part 1)
OpenID versus OAuth from the user’s perspective
What’s the difference between OpenID and OAuth?
Rails and Ruby
Ruby Weekly newsletter - If you are Rails developer, you need to read this. Always packed with great info.
Video playlist: On Writing Software Well with DHH - This is a great Rails-specific series from the creator of Rails
RailsConf 2016 - Turbolinks 5: I Can’t Believe It’s Not Native! by Sam Stephenson
RailsConf 2019 - Rethinking the View Layer with Components by Joel Hawksley
Security
OWASP cheat sheets - consult these security checklists as you architect and program.
git
I think these are the best references:
Video: Introduction to Git by Scott Chacon - this is probably the best explanation of git. It will clear up a lot of questions you may have, and things will make way more sense after watching it a few times.
Writing good commit messages
How to Write a Git Commit Message - A classic article full of good advice.
Telling Stories Through Your Commits - An amazing 10 minute talk. Essential viewing.
My favourite Git commit - A giant message for a single line commit? This article explains.
Conducting interviews
Video: Google Systems Design Interview With An Ex-Googler - This is a great mock system design question interview. Highly recommended to watch before conducting one yourself.