Books

Trading

Technical Analysis For Dummiesopen in new window.

Software development

I bought Building Trading Bots Using Javaopen in new window to understand how to build a trading bot from scratch.
To create an efficient bot, I decided to build it as a Reactive application and to learn it, I bought Hands-On Reactive Programming in Spring 5open in new window and Hands-On Reactive Programming with Reactoropen in new window.

Open Source

A good book to understand how an Open Source project works and how things are evolving: Working in Public: The Making and Maintenance of Open Source Softwareopen in new window.