Over the past few months I’ve watched a small, insanely talented team at Vercel live-migrate 100 million functions from a former vendor to Vercel. Quite a feat of engineering. The scale involved was non-trivial (single-digit % of total vercel functions) but this particular workload ended up being more niche than we anticipated. More on that later. The more painful lessons are in the runtime engineering aspect. It’s abundantly clear at this point that nothing can add more tech debt, pain, and degrade the DX more than an exotic runtime with a limited ecosystem. This is why you’ve seen Node.js endure as the standard. We’ve designed Fluid to be runtime agnostic from the outset. Our functions run stock Node.js & Python, and we’ll make it easy to bring arbitrary ones while retaining the infra benefits like cold start prevention (“scale to 1” for prod), multi-region, streaming, etc. But there’s an important missing piece. Tune in on June 25: https://t.co/qgIxLgOAFB