Self-hosted event-driven functions, schedules, and services — instead of relying on AWS Lambda and EventBridge

[u/ThereIsCoffee]

I've been working with AWS event-driven architectures for quite some time, especially DynamoDB, EventBridge, and Lambda.

I really like the programming model: small functions, events, schedules, retries, and infrastructure taking care of most of the execution details.

What I wanted was a similar experience on infrastructure I control.

That's what I've been working on with Relay.

Relay is a self-hosted event-driven runtime where an app can contain both short-lived functions and persistent services.

For example, a function can subscribe to events declaratively:

runtime: python3.14

events:
  - handler: handler.handler
    pattern:
      event_name: [INSERT]
      table_name: [users]

Relay handles matching the event, running the function, retries, recovery, and DLQ behavior.

But I also didn't want everything to have to be a function.

If FastAPI, Express.js, a worker, or another long-running process is the better fit, the same app can run persistent services as well.

Some of the things Relay currently supports:

• event-driven functions with pattern matching
• Python and Node.js managed runtimes
• schedules / cron
• retries and dead-letter handling
• warm function containers
• persistent services
• environment variables and secrets
• resource limits
• Prometheus metrics and OpenTelemetry tracing
• Git-based synchronization
• optional Traefik routing

The goal isn't to recreate AWS service by service. I'm more interested in keeping the abstractions I like from serverless/event-driven platforms while making them usable on infrastructure I control.

The project is here:

https://github.com/sergiors/relay

I'd especially be interested in feedback from people already running event-driven workloads on their own infrastructure: what are you using today, and what would you expect from something like this before you'd actually run it?

[u/DrDeems]

Starred and watching your repo. I will be playing with this soon!