Main job: migrate CodeIgniter 3 to CodeIgniter 4. Spoiler: that wasn't the only surprise on this project.
CI3 → CI4 migration
CI3 and CI4 are like two different applications. The architecture changed completely between the two versions, so a simple update was out of the question.
I created a new CI4 project from scratch, then moved the features over one by one: copy, test, fix, start again. Some modules had disappeared in CI4, so I found alternatives. Others needed an update, and that's done.
700,000 files deleted
While digging through the project I found something wild: entire libraries committed straight into the repo, abandoned for more than 13 years.
The repo weighed a ton, and the IDE froze every time you looked for a file.
The fix was simple: move those imports to a CDN.
→ 700,000 files deleted from the repo.
→ Better performance: CDNs handle caching better than static files served by hand.
→ The IDE breathes again.
Two big improvements on a legacy project that badly needed them.