I wrote the original three-part Spring Batch blog series in 2013. The code worked back then, the posts got published, and then — like most side projects — it sat untouched on GitHub for over a decade. Java 1.5, Spring 3.1, Spring Batch 2.1, JUnit 3. It was a time capsule.
These are projects I would never have gone back and updated. The effort-to-reward ratio just isn’t there when you’re doing it manually. You’d spend hours chasing down deprecated APIs, fixing broken imports, untangling framework migration guides — all for a demo project that already works.
Fast forward to now (Mar 2026), and in less than an hour (over 2 days due to token resets), I used VSCode+Claude Code to vibe code the entire modernization.