MRSV Core — Licensing & payments server in Rust

Context

Once Space Builder was becoming a real product, it needed a backend: a way to sell it, to give each customer a licence, and to know which devices use it. None of that existed. I built the server from nothing, in Rust.

My role

I designed and built the whole server myself, along with its deployment and its documentation. More recently, colleagues have added a few types and fixed minor bugs.

What I built

• Licences: creation, activation, validation, and signed offline licences so the app keeps working without a connection.
• User accounts: sign-up, login and sessions, with modern password hashing.
• Payments: Stripe checkout and webhooks, tied to orders and licences.
• Devices and presence: a heartbeat that shows which devices are active, with a limit per licence.
• Update delivery: a proxy that serves the desktop app's auto-updates from private releases.
• Beta programme: a waiting list with email confirmation, built to resist abuse, plus an intake for the feedback sent from the app and a small local admin console to manage both.
• Product telemetry for usage counters and error reports.

Deployment

I set up a complete environment on DigitalOcean and GitHub to deploy it. The server runs in Docker Compose behind a reverse proxy. A push to the release branch triggers a GitHub Actions deployment, and continuous integration builds and tests every change. A load-testing script with Locust helps check how it behaves under traffic.

Stack

Rust (edition 2024), Axum, SQLx, PostgreSQL, Stripe, Docker and Docker Compose, GitHub Actions, DigitalOcean. Documentation as an mdBook: architecture, database schema, authentication, payments and licence lifecycle.

Status

It powers the Space Builder beta. The code is private.