Next.js is not a good fit for vibe engineering (fabianlindfors.se)

Simon Willison’s “vibe engineering” critique — that coding agents can greatly accelerate development but require different tooling to avoid human bottlenecks — is the backdrop for this announcement: Fabian Lindfors is building an alternative to Next.js, called Specular (github.com/fabianlindfors/specular), designed specifically for agent-centric workflows. He argues Next.js, born before large language models became a core developer tool, lacks built-in support for the parallel, test-driven, and fully-documented stack that multiple coding agents need to work autonomously and in parallel. Technically, Specular targets three pain points: (1) parallel development — it provides isolated development environments that include services and databases so many agents can run and interact concurrently without manual orchestration; (2) testing and automation — it includes a testing framework meant to be written and iterated on by agents, and lets agents run their own tests against the isolated environments; (3) documentation — it offers a local MCP you can plug into an agent to supply accurate, full-stack context beyond Next.js’s frontend-centric training coverage. If it delivers, Specular could shift how teams integrate coding agents into CI, dev workflows, and system design by reducing manual setup and increasing agent autonomy; the project will be open-sourced soon.