Modern multiplayer games demand more than fast servers - they require persistent, reliable, low-latency communication at massive scale, often under highly unpredictable traffic patterns. Launch days, seasonal events, and promotions can generate connection spikes that dwarf steady-state traffic, while players still expect real-time responsiveness and stability.
In this post, we’ll explore how a game studio building a large-scale online RPG addressed these challenges using Azure Web PubSub, and what lessons other game developers can apply when designing their own real-time backend architectures.
The challenge: from polling to real-time multiplayer
The studio began with a backend architecture that relied heavily on polling a centralized data store to synchronize multiplayer state - such as party invitations, friend presence, and session updates - across geographically distributed game servers.
This approach worked initially, but it came with clear drawbacks:
- High latency (5 seconds or more for critical interactions)
- Wasted compute resources due to constant polling
- A difficult trade-off between cost and responsiveness
- Limited flexibility to introduce richer real-time features
As multiplayer adoption grew and concurrency increased into the hundreds of thousands, these limitations became increasingly painful - especially during major releases and promotional events.
“Building multiplayer games is very different from building typical business APIs. Small timing and synchronization issues are immediately visible to players.”
The team needed a solution that could:
- Maintain persistent connections at scale
- Deliver near real-time updates without polling
- Handle spiky traffic patterns without over-provisioning
- Minimize operational complexity
Why a managed real-time service?
The initial instinct was to build a custom WebSocket infrastructure in-house. But persistent connections, failover, reconnection logic, scaling behavior, and regional distribution quickly added up to a large and risky engineering effort.
Instead, the team opted for Azure Web PubSub, a fully managed service designed for large-scale, real-time messaging over WebSockets. What stood out wasn’t just performance but the operational simplicity and cost model.
Architecture shift: event-driven, not poll-driven
After adopting Azure Web PubSub, the backend architecture changed fundamentally:
- Game servers maintain persistent WebSocket connections to Web PubSub
- Backend services publish messages only when state changes
- Database change feeds trigger real-time updates
- Messages are routed efficiently using groups, targeting only relevant servers or players
This eliminated polling entirely and unlocked new real-time capabilities with minimal additional complexity.
Key benefits for multiplayer games
Push-based real-time updates
State changes - such as party invites or presence updates - are delivered immediately instead of waiting for polling intervals. What once took seconds now arrives in tens of milliseconds.
Massive, elastic scalability
Azure Web PubSub supports:
- Up to 1 million concurrent connections per resource
- Auto-scaling based on actual demand
- Geo-replication for resilience and global reach
This makes it well-suited for launch-day spikes, where traffic may surge for a few weeks and then settle to a much lower baseline.
Low-latency at global scale
In practice, backend-to-service latency stays in single-digit milliseconds, with end-to-end delivery typically under 100 ms - a dramatic improvement over polling-based designs.
For asynchronous game features, even modest latency differences can significantly improve perceived responsiveness.
Cost efficiency for spiky traffic
A critical insight for game workloads is how Azure Web PubSub pricing works:
- Billing is based on units × time used (in seconds), aggregated daily
- Short-lived spikes don’t incur full-day costs
- You don’t pay for unused capacity once traffic drops
This makes Web PubSub particularly attractive for games with:
- Large launch peaks
- Periodic promotional spikes
- Lower steady-state concurrency
Designing for launch peaks without overpaying
One of the most common questions game teams ask is:
"How do we handle massive launch traffic without locking ourselves into long-term costs?"
Recommended approach
During launch or major promotions
- Provision a fixed capacity with ~20% headroom
- Avoid auto-scaling delays during critical windows
- Use multiple regional P1-tier resources instead of a single large P2
After traffic stabilizes
- Enable auto-scale
- Reduce baseline units
- Keep capacity aligned with real usage
This strategy balances reliability, latency, and cost, while avoiding unnecessary complexity during the most critical periods.
Reliability, geo-distribution, and sharding
Rather than relying on one large global endpoint, the recommended pattern is to:
- Deploy multiple Web PubSub resources per continent
- Shard users by geography
- Use geo-replicas primarily for disaster recovery
- Optionally implement lightweight routing logic when multiple resources exist in a single region
This improves fault isolation, reduces blast radius, and aligns well with how large game backends already segment players.
Security considerations for WebSocket-based games
Persistent connections introduce different threat models than traditional REST APIs. Key protections include:
- Authenticated connection tokens
- Enforcing one connection per user
- Rate limiting connection attempts
- Message size and throughput controls
For additional protection, Azure Web PubSub can be combined with services like Azure Front Door, which natively supports WebSockets.
Why this matters for game developers
What this real-world scenario highlights is a broader trend: multiplayer games increasingly resemble real-time distributed systems, not just applications with APIs.
By adopting a managed real-time service like Azure Web PubSub, teams can:
- Ship features faster
- Reduce operational risk
- Scale confidently through unpredictable demand
- Pay only for what they actually use
Instead of spending engineering effort reinventing infrastructure, teams can focus on what truly differentiates their game: player experience.
Microsoft