Developer Rebuilt Express in C++ to Understand It, Achieved 4.8x Speed Gain

A developer at FYCLabs who struggled to understand Express's middleware chaining decided to rebuild the framework from scratch in C++ rather than simply reading its source code. The project, called PlusWeb, revealed that Express uses a linear route-matching scan, meaning routing performance degrades as more routes are registered. By implementing a segment-based trie instead, PlusWeb maintained roughly 90,000 requests per second regardless of route count, while Express dropped to 355 rps with 10,000 routes. On a realistic five-route application, PlusWeb outperformed Express 5 by about 4.8 times. The developer also learned through a side project building a JavaScript interpreter that Node.js itself wraps libuv, leading them to eventually adopt the library rather than maintain their own event loop.