programming

02 Nov 2026

DZone Java Zone

Build a GitHub Contribution City With Java and Quarkus

GitHub's contribution calendar gives you an already iconic overview of your activity over the year. Each day has a square, and its color changes with the contribution level. And of course, those days and contributions can also be arranged into buildings, with a week becoming a small part of a city and busier weeks adding height to the skyline.

I had some spare minutes and built Quarkus Contribution City around this idea, using Java and Quarkus to generate an SVG from GitHub's contribution data. The visual inspiration came from Pink Pixel's skyline, and you can see a version with my real data on my GitHub profile. A scheduled GitHub Action updates the image at night.

02 Nov 2026 2:00pm GMT

29 Oct 2026

DZone Java Zone

Stop Writing Database Migration Scripts: Declarative Schema Sync for Java

If you have worked on a mature Java backend application, your src/main/resources/db/migration folder probably looks like a chaotic history ledger:

Plain Text
 

V1__init_schema.sql
V2__add_users_table.sql
...
V142__add_status_column.sql
V143__fix_status_typo.sql
V144__drop_old_status.sql
V145__add_missing_index.sql

29 Oct 2026 12:00pm GMT

28 Oct 2026

DZone Java Zone

Searching Kafka Without an Index: Lessons From Building Message Search for Kafdrop

The message left the first service at 2:14 PM and never reached the last one. Between those facts: four pipeline stages, six topics, a pub/sub API moving every record. The engineer on call had Kafdrop open, the offsets looked fine, and nobody could say which stage had eaten the record.

That gap is why we built message search for Kafdrop at a hackathon. The setup was familiar from my day job: a platform moving data between pipeline stages over a pub/sub API, with no way to ask where a message went when something breaks. Kafdrop showed partitions and offsets. It couldn't search inside the messages.

28 Oct 2026 1:00pm GMT