Our Best Customers Are Now Robots

Summary

Fly.io reports that users driving the platform’s most recent growth are robots rather than people, prompting a reconsideration of developer experience (DX) as the primary product lens. The post describes how vibe-coding workflows use Fly Machines—Docker containers running as hardware-isolated virtual machines—to create, modify, stop, and rapidly restart environments without paying during stopped periods. These workflows favor incremental filesystem state, object storage, and controllable routing for MCP connections, including potentially long-lived SSE connections that should reach the same stateful instance. Fly.io also proposes exposing its API through MCP and using sealed, tokenized secrets so isolated machines can substitute real OAuth credentials only when needed. It concludes that a useful robot experience (RX) will require more than an MCP interface, while managed Postgres remains the company’s most important engineering priority and the platform is still primarily designed for humans.

Takeaways

1. 1

   A Fly Machine can start in double-digit milliseconds, persist as long as needed, and be stopped without billing; restarting an existing machine is distinct from creating one.

2. 2

   Vibe-coding workflows incrementally add packages, source changes, and systemd units to a minimal base image, making filesystem storage useful despite conventional immutable OCI container practices.

3. 3

   MCP may require long-lived connections to reach the same stateful instance, while sealed and tokenized secrets can let isolated machines substitute real OAuth credentials only when needed.