HOW WE MIGRATED 11 MILLION USERS TO CLINE'S BIGGEST REFACTOR

Summary from the TLDR Dev newsletter

Cline replaced its VS Code extension's roughly 76,000-line monolithic agent core with a shared SDK while protecting workflows used by more than 11 million developers. Since the VS Code Marketplace lacks gradual rollouts, the team bundled legacy and new engines together behind a feature flag with automatic fallback, then ran a month-long A/B rollout that reduced tasks hitting three consecutive agent mistakes from 6.34% to 0.62%.