How to Build Java Applications Today: #59


Welcome to my newsletter “How To Build Java Applications Today”! If you like it, then subscribe to it on Substack! Or read it on or Medium. Even better: Share it with people who may be interested.

Next Issue: Wednesday, February 2, 2022

My newsletter is published on the first Wednesday of every month.


Are you still Log4Shell-shocked? Too soon? My last newsletter issue appeared on December 7, 2021, just two days before Log4Shell got disclosed. Feels like an eternity ago, doesn’t it? Well, I had to write about Log4Shell as well — see below.

When I thought I got the hang of my new monthly cadence, I made many changes again. As promised last month, I have a new section in my newsletter. Not one but three: News are back in “New & Noteworthy”, the “Release Radar” lists essential releases, and the “Editorial” is my monthly opinion piece. This month, there can be only one topic for the editorial. So please read it: Log4Shell Shows The Need for “Trustworthy Java”.



I’m a full-stack Java developer with 23 years of experience: Spring Boot, Angular, Flutter. I’m looking for a project in May 2022, in Milton Keynes, London, or remote. I’ll work as a contractor or fixed-term employee but don’t take permanent positions.

Interested? Then check out my resume & work samples!

Check out my resume & work samples

New & Noteworthy

This new section has the most important news for Java developers from last month — in my opinion, at least.

Critical Log4j Vulnerability Log4Shell with Zero-Day Exploits, Garbage Collection Improvements from JDK 8 to JDK 17, Red Hat Reluctant on Proposed 2-Year Java LTS Cadence, JetBrains IDEs Get Remote Development, JetBrains Clones Visual Studio Code — But At What Price, An Oral History of Stack Overflow — Told By its Founding Team, and Benedict Evans’ Annual Tech Presentation.

Read New & Noteworthy

Technology Index

What do we need to build a Java application today? A JVM language, a database, a back-end framework, a web framework, and — if we want to get fancy — a mobile app framework. So my index recommends technologies in these five areas, based on popularity, industry analysis, and my 23 years of Java experience.

Why am I measuring popularity?

Picking a popular technology makes our developer life easier: Easier to learn, easier to build, debug & deploy, easier to hire, and easier to convince teammates & bosses. Popularity can make a difference in two situations: When multiple technologies score the same, you could go for the most popular one. And when a technology is very unpopular, we may not use it.

How am I measuring popularity?

I measure popularity by systematically observing what millions of developers do: Google searches to measure interest, Udemy course buyers to measure learning, Stack Overflow questions to measure learning & application of technologies, and mentions in Indeed job ads to measure the demand for technologies.

So what’s changed over the index from December?

  • I updated all charts for all technologies with the latest numbers. I collected the data from December 28–31, 2021.
  • All technologies now compare the numbers of Udemy students and job ad mentions against a previous month. This hints at trends, but these trends need more time to become visible.

Read the Technology Index

Release Radar

This new section has the current releases of essential tools & technologies for Java developers. I shamelessly stole the name from GitHub because I’m an aspiring allegorist. 😌

Last month saw new releases for Gradle, Spring Boot, Quarkus, DropWizard, IntelliJ, and Eclipse.

Read the Release Radar


This new section is my opinion on an important topic of the month.

I believe Log4Shell is Java’s biggest crisis ever. How did we handle Log4Shell? And how can we prevent another Log4Shell? My answers are in this month’s editorial: Log4Shell Shows The Need for “Trustworthy Java”.

Read the Editorial


Karsten Silz is the author of this newsletter. He is a full-stack web & mobile developer with 23 years of Java experience, author, speaker, and marathon runner. Karsten got a Master’s degree in Computer Science at the Dresden University of Technology (Germany) in 1996.

Karsten has worked in Europe and the US. He co-founded a software start-up in the US in 2004. Karsten led product development for 13 years and left after the company was sold successfully. He co-founded the UK SaaS start-up “ Your Home in Good Hands” as CTO in 2020. Since 2019, Karsten also works as a contractor in the UK.

Karsten has this newsletter, a developer website, and a contractor site. He’s on LinkedIn, Twitter, and GitHub. Karsten is also an author at InfoQ.

Originally published at on January 5, 2022.




Karsten Silz is a full-stack web & mobile developer with 23 years of Java experience, author, speaker, and contractor.

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Karsten Silz

Karsten Silz

Karsten Silz is a full-stack web & mobile developer with 23 years of Java experience, author, speaker, and contractor.

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