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Technical insights on Java, Spring Boot, and Cloud Native development. Sharing lessons learned from enterprise experiences, code examples, and architecture patterns that actually work.
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Recent Post
A Customer Couldn’t Upload an Invoice. The Fix Re-Taught Me XSD, JAXB, and Maven.
A Polish customer reports their invoice won’t upload.
The file looks valid. Other Polish customers upload fine.
Three days later I’ve read more of the Polish Tax Code than I’d like to admit.
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What Jackson Doesn’t Deserialize for Free: The Empty Array That Took Down a Production Endpoint
A 503. Every 30 seconds, on the dot.
Sentry was empty. The application logs said the request was fine.
Then we looked at what Jackson was actually parsing.
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One Email. Two Invoices. The 10-Month Bug Hiding Behind a Slack Alert.
A Slack alert said “duplicate notification.”
A 2-line fix would have shipped it the same day.
Both were wrong.
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Jackson From First Principles: What ObjectMapper Does, What It Doesn’t, and When to Write a Custom Serializer
I’ve used ObjectMapper for years without really understanding what it does for free, what it refuses to do, and when you actually need to step in with a custom serializer.
save, saveAndFlush, and REQUIRES_NEW: The Hibernate Questions Hiding in One Spring Service Method
Last week I was reading a teammate’s PR and stopped on a method that made me realise I’d been writing Spring + Hibernate code for years without actually understanding what save, flush, commit, and REQUIRES_NEW each do.
Javadoc Best Practices for Spring Boot - 5-Minute Professional Guide 2025
You’ve written clean code. Your tests pass. Your PR is ready. Then comes the review comment: “Please add Javadoc.”
Sound familiar?
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