Descriptions:
Web Dev Cody puts Claude Opus 4.7 to a genuine stress test: migrating a live production app — with a real user base and over 250,000 generated icons in the database — from Next.js and tRPC to TanStack Start. The video explores Claude Code’s effort level system (high, extra high, and max), what Anthropic’s own documentation recommends for complex agentic coding tasks, and why Cody opts to set a 64,000 token ceiling before firing off the migration prompt.
The model spends roughly 28 minutes planning the refactor before execution begins, at which point a series of real errors surface: missing config files, React’s `use()` hook failing under TanStack Start’s server-side rendering pass, and Auth.js callback route mismatches. Cody works through each issue iteratively by pasting errors back into the model, eventually restoring user authentication and icon generation functionality.
The honest conclusion is that Claude Opus 4.7 at max effort is capable but not infallible on large-scope framework migrations. Cody notes that attempting to swap out an entire framework in a single pass is likely too broad a prompt for any model to one-shot reliably, and recommends keeping refactoring tasks narrow and incremental. Developers considering similar AI-assisted migrations will find this a grounded, unvarnished look at what current models can and cannot handle.
📺 Source: Web Dev Cody · Published April 23, 2026
🏷️ Format: Hands On Build
