Showing Post From Spring-Boot
The Production Outage — Where the Fix Was Worse Than the Bug
One missing property line.
Two production outages.
The hot fix between them made the second one inevitable.
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Threads, @Async, @Transactional, and Virtual Threads: What Actually Happens Inside a Spring Boot Backend
A webhook fires. One HTTP request comes in.
Ten seconds later, half the app is returning 503s.
The bug is not in the webhook.
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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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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.
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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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 something: I’d been using save, flush, commit, and REQUIRES_NEW correctly for years — and if a junior had asked me to explain precisely what each one does and when, my answer would have been thinner than my code. Using a tool and being able to teach it are different skills, and the gap only shows when someone asks.