HonarAmoozesh
Solutions Architect (Project Contract)
Jul 2025 – Nov 2025
Challenge
Scale a virtual classroom to 1,200+ concurrent users with low latency and sustainable cost. Support real-time WebRTC and HLS fallback, plus seamless role promotion and room management.
Solution
Dual-stream architecture: LiveKit SFU for WebRTC; NATS JetStream for sub-100ms signaling (roles, dynamic rooms). HLS for passive viewing at scale. HAProxy in front of LiveKit; Prometheus for observability.
Results
- •1,200+ concurrent users on hybrid WebRTC/HLS.
- •78% infrastructure cost reduction with improved reliability.
- •Sub-100ms signaling for role and room operations.
Architecture
flowchart TD C[Browser / App] C <-->|signaling sub-100ms| N[NATS JetStream] C -->|WebRTC| H[HAProxy] H --> L[LiveKit SFU] L --> C C -->|playback| HLS[HLS Stream] L --> P[Prometheus]