RedPennon, feature flags we built and run

RedPennon is a hosted feature flag service. Software teams use it to turn features on and off, roll them out to some users first, and run experiments, without shipping new code each time.

We built it, we launched it in June 2026, and we run it.

What it does

• Targeting. Ordered rules by user ID, email, IP or a reusable audience, including percentage rollouts.
• Environments. Development, testing and production each have their own API key and their own values.
• Safe defaults. A new flag is never on in production until someone turns it on.
• Code references. A command-line tool scans a repository in CI and shows where each flag is used, so stale flags can be found and removed.
• Audit trail and roles. Changes to flags and rules are recorded with who made them, and production has guards.
• Clients. Official SDKs for Node, Go and Python share one REST API, and plain HTTP works with any stack.

How it is built

The application is Python and Django, with HTMX and Alpine.js on the front end and PostgreSQL behind it. The flag evaluation API is a separate service, kept small so it can be fast. It is designed for a 95th-percentile response under 50 milliseconds. The product runs on AWS in Sydney.

Why we run it ourselves

It is a real application with real customers, built the way we build for clients: scoped around the problem, tested, hosted and looked after by the same people. If you need custom software to run a process in your business, that is what we do.