GIT

• APress Git Pro Ebook – free
• Git Cheat Sheet

API

• Nordic APIs
• API Evangelist
• API Handyman
• OWASP
• Swagger Hub
• Apiary
• API Friends
• API Academy

Oracle Cloud

• OraWorld
• Red Thunder Blog
• PaaS Community
• Developer Community
• Tech Trantor
• AMIS Oracle Blog
• Oracle Groundbreakers (unofficial)
• OCI Geek
• Todd Sharp
• Foggy Kitchen

Development

• CNCF
• CI/CD Foundation
• Container Journal
• Chris Richardson’s Micerservices.io
• ThoughtWorks Tech Insights
• Martin Fowler
• Neal Ford
• Sam Newman

Integration

• Gregor Hohpe
• Thomas Erl (Arcitura)
• Confluence/Kafka

Publisher Free Content

• Manning
• Packt
• Apress – Pro GIT, InfoSec Handbook etc
• RedHat sponsored ebooks also RedHat sponsors Havard Biz Reviewe articles for free into the Harvard Business Review at the EnterpriserProject site

UI/UX

• https://www.interaction-design.org/
• Don Norman
• Nielsen Norman Group