Building a Real-Time, Event-Sourced Feature Flag System with Rust and WebAssembly
Disabling or enabling features at runtime is a common need in modern software. A robust feature flag system lets product teams experiment safely, roll out changes gradually, and reduce blast radius during incidents. In this tutorial, you’ll build a lightweight, real-time, event-sourced feature flag service composed of: a Rust-based event store, a WebAssembly (wasm) client surface, and a small Node.js server for orchestration. The approach emphasizes correctness, observability, and low latency, while staying approachable for practical use in real projects.
What you’ll learn
Principles of event sourcing for feature flags and how it improves auditability and rollbacks
Designing a compact event schema for feature flag lifecycle events
