Can the MERN MVP scale after launch?

Yes. The MERN MVP is built with the scaling path in mind from week one. MongoDB Atlas lets you upgrade cluster tiers and add read replicas as query load grows. Node.js cluster mode handles concurrency scaling without a rewrite. Redis caching is added as traffic grows. React with Next.js supports incremental static regeneration for marketing pages. The architecture decisions in the discovery sprint protect against expensive refactors that come from an MVP built without a growth plan.