Anthropic's engineering retrospective revealed that after two weeks of on-site testing with Slack for its internal research version of Claude, it successfully boosted the overall speed of the claude.ai web version and desktop client by 3 times. Previously, the performance bottleneck stemmed from Claude's frequent use of non-Latin-1 characters, such as dashes, which caused the V8 engine to convert entire text segments into slower double-byte format storage. This significantly increased the time required for code syntax highlighting, with Chinese users being particularly affected due to the presence of Chinese characters in responses. The issue was resolved with just 20 lines of code. During the optimization process, Claude accomplished the majority of performance improvements, implementing over 3,000 underlying changes that resulted in up to a 5.6-fold increase in core interaction metrics. The entire process was free of user-perceptible incidents and required no rollbacks, with humans primarily responsible for driving the speed improvements and overseeing final acceptance.