Yes. String-processing tweets (linkify and emoji-insert) and crunching numbers for time series line charts were two areas where we saw some lag. It was React so

Yes. String-processing tweets (linkify and emoji-insert) and crunching numbers for time series line charts were two areas where we saw some lag. It was React so these bottlenecks were happening during virtual DOM rendering. And realizing GP was talking about client-side, but also don't forget server-side, where DOM doesn't exist and the hyper-focus on pure-JS perf is much appreciated.