Here are a few great books that are helpful too clarify some important concepts and techniques in software development.

In no particular order :

1- POODR by Sandy Metz.
A Ruby classic.
Why is it good ?
Like a lot of people, I hear the hype around some technology.
There's a lot of hype... especially regarding frameworks, architecture etc... But when you're actually coding something, you're probably more concerned about how well you've just coded a feature, or whether the refactoring you just did is actually an improvement of what was there before. This book is all about tradeoffs and how to improve your code, in the short, medium and long term.

Sandy Metz is a great writer, and speaker, she has a wealth of knowledge and can present ideas and concepts with such a unique analysis, she just lays it out in front of you to see...

...and everyone should try the squint test!

2- Efficient Linux at the Command Line by Daniel Barrett
Why is it good ?
This is book allowed me to get better at a core software skill. The command line.

I got quite comfortable with using the terminal before reading this book, but my knowledge was actually limited to the git commands, cd, mkdir, curl, dig etc... all the standard commands.

This book sets out to take those skills to the next level, and it does just that! I wrote some shell scripts and have a lot more confidence in understanding other peoples command line scripts.

3- Ruby on Rails Tutorial by Michael Hartl
Why is it good ?
It's clearlty written and covers more in depth topics than you would expect from a typical tutorial. It's a really high quality book. Although I skimmed through a lot of the beginning (as I wasn't starting from 0 in Rails), I learnt a lot!

Definitaly a go to for Rails ! Especially as they are updated with every major Rails release.

And for 2024:
I've started Layered Design for Ruby on Rails Applications by Vladimir Dementyev. Just started and it's already boosting my knowledge !