Design Principles

These principles guide how WoW Lab is built.

Free engine, always

The full engine runs in the browser via WebAssembly. No sign-up needed, no setup, nothing to install. Paid plans add hosted pool access for speed, but the engine itself is the same binary either way.

Stateless services

Sentinel and Beacon instances are stateless and interchangeable. Any Sentinel can handle any request. Any pool worker can process any chunk.

Centrifugo owns connections

Centrifugo manages all WebSocket connections:

• Connection lifecycle and reconnection
• Presence tracking and subscription management
• Message routing and delivery guarantees
• Horizontal scaling across multiple instances

Services publish messages to Centrifugo rather than maintaining direct connections to clients.

Idempotency everywhere

Every operation must be safe to retry:

• Chunk processing is deterministic given the same seed
• Progress updates use last-write-wins semantics
• Job state transitions are guarded by version checks
• Network failures never leave the system in an inconsistent state

Eventual persistence

• Realtime updates flow through Centrifugo
• Supabase stores durable records
• User-facing data is eventually consistent within seconds
• Simulation results are batched for efficient storage