otp-thinking

name	otp-thinking
description	Use when implementing GenServer, Supervisor, Task, Registry, PubSub, process state, retries, scheduling, queues, or BEAM fault-tolerance design.
license	Apache-2.0

OTP Thinking

Use this skill when runtime behavior matters.

Principles

• A GenServer is a serialization point; use it only when that bottleneck is intentional.
• Supervisors restart processes; design what state is lost, rebuilt, or persisted.
• Prefer Tasks for one-off concurrent work and GenServer for owned lifecycle/state.
• Use Registry or process names when discovery is required; avoid global names for per-tenant/per-user resources.
• Think about mailbox growth, back-pressure, timeouts, and crash loops.
• "Let it crash" means design recovery, not ignore errors.

Workflow

1. Define the runtime reason for each process.
2. Define ownership of state and messages.
3. Pick supervision strategy and restart policy.
4. Specify observability: logs, telemetry, and failure signals.
5. Validate with focused unit tests plus concurrency/failure tests where useful.