realtime-and-integrations

Replace hub method invocations with explicit JSON message envelopes such as auth, subscribe, and join-room, then implement a gateway using the `ws` library. Map SignalR groups to in-memory room sets and validate tokens during the upgrade handshake or as the first socket message.

Use `ws` for lightweight raw WebSocket with minimal dependencies when you can own auth, rooms, and reconnect logic. Choose Socket.IO when the source system relies heavily on SignalR rooms, acknowledgements, and automatic reconnection, noting it uses a custom protocol requiring Socket.IO clients.

Emit NOTIFY events from triggers or application code, keep one dedicated backend pg client running LISTEN, and forward notifications to a WebSocket broadcaster. On the frontend, a useWebSocketSubscription hook invalidates TanStack Query keys so components refetch fresh data.

Use postgres_fdw for Postgres-to-Postgres federation or tds_fdw to query SQL Server from Postgres. For hot-path reads, prefer an integration service that combines results in TypeScript or replicate the remote data into Postgres via CDC or ETL.

Yes, Container Apps supports WebSocket ingress out of the box when ingress transport is set to auto, so no custom sidecar is needed. For multi-replica deployments, each replica owns only its local sockets, so use Postgres NOTIFY or Service Bus to fan out events.

Choose ExpressRoute for latency-sensitive or high-volume traffic, site-to-site VPN for moderate workloads, and Azure Relay or Hybrid Connections for a few individual endpoints. Use APIM with VNet integration when on-prem SOAP or REST services need a policy facade.