Kotlin
- 9 Extension Function Secrets in Kotlin – Nine Pages Of My Life
Not really secrets but a good recap if you learned Extension Functions some time ago - 5 Hidden Secrets of Kotlin Coroutines: I wish I Knew It Earlier – Jayant Kumar
If you have learned Coroutines, you should read this too - 12 tips to mastering Kotlin Coroutines – Artem Asoyan
Another good article about Coroutines - Why Your Kotlin Code Might Be Slower Than You Think (And How to Fix It) –Jayant Kumar
New to me: “Default Arguments in Inline Functions” and “Using List.map Inside Layouts or Loops” (with remember) - Why Exceptions shouldn’t be objects in Kotlin – Michal Ankiersztajn
Exceptions should be classes and here it is explained
Java / JDK
- Creative Ways to Use Interfaces in Java – Skilled Coder
Nice ideas to think about - Secret Java Stream Hacks You’ve Never Heard Of (But Will Instantly Love) – Rasathurai Karan
Java Stream can be really powerful – if you know them well - Mastering Java Streams: Tricky Employee Data Challenges You Must Solve! (Must Know) – Lets Learn Now
Very practical tasks and their solutions - How to Serialize and Deserialize Dates in Avro – Andrei Branza
Very detailed description of date/time conversions in Avro - Choosing Wisely: for vs. forEach in Kotlin (A Thinking Dev’s Perspective) – Blundell
My opinion: if there are control structures in a forEach then that isn’t the functional approach (so use “for” or make it more functional - How I Made My Java Code 15x Faster: A Deep Dive into Profiling and Optimization – Yashbatra
Some good and reasonable ideas to reduce build time - How to write JUNIT test cases for Static Classes and Static Methods in Java – Full Stack Developer
Mockito comes to help when using static functions
Spring Boot
- Stop Using Spring Boot @Transactional Everywhere: Understand When You Actually Need It – Ramesh Fadatare
This article nails it: when and how to use @Transactional - Java 21 Docker Optimization: 5 Best Practices for Faster, Secure Containers – Juan Manuel Lopez
If you create Docker containers for Java applications, you have to read this article - Spring Boot Security Is Broken in 2025 — Here’s How OWASP Top 10 Proves It – Himanshu
Check every item in your code, these are really important
Architecture
- Forget the Outbox Pattern: Change Data Capture is King – Patrick Koss
CDC is an interessting pattern, but also be aware of catches in asynchronous processes
General
- This new IDE from Google is an absolute game changer – Tari Ibaba
So many new IDEs, IDX is an IDE in the cloud and the next step has already taken place: Firebase Studio - How I Cut My Gradle Build Time by 50% – James Cullimore
This can really reduce build times – and think how often you build and how boring it can be to wait