A deep dive into pre-hydration rendering, critical CSS, vanilla JS, and what it actually means to contribute to open source By Sulagna Ghosh | Open Source Contributor, Meshery I came to this bug expecting to spend 20 minutes adding a few lines of CSS. Several days later, I had learned more about how Next.js actually works than I had in months of using it. I had navigated a Turbopack internal error, discovered why CSS imports can arrive too late, traced a root cause through 2022 commit history, understood the difference between two completely separate loading screens in the same codebase, tried a JS solution that was almost right, implemented an inline CSS fix, defended it through code review, and then collaborated with a maintainer to produce a solution that combined both approaches elegantly. This is the full story — including the wrong turns.…