April 2026 focused on improving the responsiveness of text editing in the egui repository (emilk/egui). Implemented an O(n) word-boundary scanning solution by introducing a running character counter, replacing repeated per-segment scans and eliminating the O(n^2) bottleneck for large buffers. The work included regression tests and a large-text performance benchmark, tracked in commit 4016dee2bdbfeaecfed529edb6a155088f775119 (co-authored by Claude Opus). Result: dramatic UX improvements for large documents, with latency reduced from tens of seconds to milliseconds in worst-case benchmarks (up to ~1,600x speedup). This enhances editing smoothness, reduces perceived freezes, and improves reliability for large texts. Skills demonstrated include algorithm optimization, test-driven development, performance benchmarking, and collaborative execution across the team.