Midjourney Powers Web Stack on Bun with Five Engineers Serving Millions (twitter.com)

Midjourney says it now runs its web stack on Bun, the JavaScript runtime/toolchain built on Zig, and that a team of just five engineers is maintaining the service while serving millions of users. The move is notable because Midjourney is a high-traffic, latency-sensitive AI product; running its web layer on Bun signals confidence that the runtime can handle production load, reduce operational overhead, and accelerate developer workflows without a large backend team. Technically, Bun consolidates runtime, bundler and package manager into a single toolchain, promising faster cold starts, lower memory footprints, and quicker builds compared with traditional Node.js setups. For the AI/ML community this matters: interactive model UIs and image generation frontends benefit from lower latency and simpler deployments, and startups can scale user-facing infrastructure with far smaller teams and costs. The story also puts pressure on the Node/Deno ecosystem and raises practical questions—native module compatibility, long-term stability and tooling maturity—that teams should evaluate before switching. Overall, Midjourney’s shift is an important production endorsement of Bun’s performance and developer-productivity tradeoffs for AI-driven web services.