A speed-to-lead engine, running in production

The problem

A business that replies to an enquiry within the hour is far more likely to win it than one that replies the next day, yet many never reply at all. We wanted a follow-up engine we could deploy for any client, where every branch of the logic is covered by automated tests and the delivery documents cannot quietly fall out of step with the code.

What we built

A TypeScript service on Fastify, with Supabase for lead records and Resend for email, hosted on Railway. We chose code over a visual workflow tool because a workflow canvas cannot be unit tested and per-client copies drift apart; n8n stays at the edge as a connector. Email, SMS (Twilio) and AI voice (Vapi) channels sit behind the same interface, so a client can start with email and add channels later. The written delivery process is checked against the code by an automated test that fails when the two disagree.

Where it stands

Running in production on Railway since 23 August 2026. The email path is proven against a real send. The SMS and voice channels are built and tested but have not yet been exercised against a live phone number. The engine has not yet run for a client; it is the base our first client deployments start from.