How I Improved Email Rendering Performance 15x Using Rust + WebAssembly (Next.js 16 Devlog)

I decided to do something scary: Build a SaaS product in public, from scratch, sharing every win and every embarrassing error log along the way. The product is Ansomail —an AI-powered drag-and-drop email editor. The goal? To build a tool where Developers set the rules (Design System) and Marketers just drag-and-drop blocks, without ever breaking the layout. Here is the unvarnished truth of my first week: battling the "bleeding edge" tax of Next.js 16, crashing my database, and eventually rewriting my engine in Rust for a 15x speed boost. The Stack: Betting on Speed I didn't want a legacy stack. I wanted speed. Runtime: Bun (for instant startup) Framework: Next.js 16 (Turbopack) Monorepo: Turborepo (preparing for the Ansospace ecosystem) Database: Postgres + Drizzle ORM Linting: Biome (Farewell, ESLint) It looked perfect on paper. Then I started coding. Days 1-2: The Architecture & The "AI Architect" The first challenge wasn't code; it was philosophy. How do you stop an AI from generati