Cline with Gemini 2.5 (https://cline.bot/)

Framelink MCP (https://github.com/GLips/Figma-Context-MCP)

Playwright MCP (https://github.com/microsoft/playwright-mcp)

Pull down designs via Framelink, optionally enrich with PNG exports of nodes added as image uploads to the prompt, write out the components, test/verify via Playwright MCP.

Gemini has a 1M context size now, so this applies to large mature codebases as well as greenfield. The key thing here is the coding agent being really clever about maintaining its' context; you don't need to fit an entire codebase into a single prompt in the same way that you don't need to fit the entire codebase into your head to make a change, you just need enough context on the structure and form to maintain the correct patterns.