Multiplayer applications are fundamentally different from traditional REST APIs.
In a typical API, a client sends a request:
Client → Server → Response
A multiplayer game needs something closer to:
Player A ─┐
├──→ Server ──→ Player A
Player B ─┤ ├→ Player B
Player C ─┘ └→ Player C
Players are constantly sending events, receiving updates, joining rooms, leaving rooms, and reacting to what other players are doing.
That makes the backend architecture extremely important.
This is one of the areas I want StreetJS to make easier.
The WebSocket connection
Instead of repeatedly polling a REST endpoint, players can maintain a persistent connection with the server.
For example:
const socket = new WebSocket(
'wss://game.example.com'
);
Once connected, the client can send events such as:
{
"type": "player.move",
"x": 120,
"y": 340
}
The server processes the event and broadcasts the relevant state change to other players.
Rooms
A multiplayer backend usually needs the concept of a room.
For example:
Room: game-4821
Player 1
Player 2
Player 3
Player 4
Players joining the same room become part of the same realtime context.
The server can maintain the relationship:
Room
├── Player A
├── Player B
├── Player C
└── Player D
When Player A performs an action, the server determines which players should receive the event.
This is much more efficient than broadcasting every event to every connected client.
The server should be authoritative
One of the biggest architectural decisions in multiplayer systems is deciding who controls the game state.
The client should not be trusted to decide:
"I won."
"I have 10,000 coins."
"My player is at position X."
"I dealt 5,000 damage."
The server should validate important actions and maintain authoritative state.
A simplified flow looks like:
Player
↓
WebSocket Event
↓
Validation
↓
Game Logic
↓
Authoritative State
↓
Broadcast
↓
Other Players
This becomes especially important when the application involves competition, rankings, virtual items, or anything that could be manipulated by a client.
Where StreetJS fits
StreetJS is designed as a TypeScript-first backend framework for Node.js.
For a multiplayer application, the backend can combine several capabilities:
WebSockets
Persistent connections and realtime events.
Authentication
Identify players before allowing them into protected game sessions.
Validation
Validate incoming events before they reach game logic.
Services
Keep game rules separate from transport logic.
PostgreSQL
Persist users, games, matches, rankings, inventories and other durable data.
Telemetry
Monitor connections, errors and application behavior.
The important part isn't having individual features.
It's having them work together as one backend architecture.
Realtime state vs persistent state
Not everything belongs in the database.
For example, temporary state such as:
Current player position
Current room membership
Active connection
Current match state
may need to live in memory or a dedicated realtime state layer for fast access.
Persistent information such as:
User account
Match history
Leaderboard
Player statistics
Purchases
Achievements
belongs in durable storage.
A good multiplayer architecture needs to clearly separate these two worlds.
Scaling becomes a different problem
A single server can handle a small multiplayer application.
Eventually you may have:
Load Balancer
│
┌──────────┼──────────┐
↓ ↓ ↓
Server A Server B Server C
│ │ │
└──────────┼──────────┘
↓
Shared State
↓
PostgreSQL
Now things become more complicated.
What happens when two players in the same room are connected to different servers?
How do servers synchronize events?
What happens when a server crashes?
How do you reconnect a player?
How do you prevent duplicate events?
These aren't just WebSocket problems.
They're distributed-systems problems.
That's what makes multiplayer interesting
Building a multiplayer backend isn't simply:
"Add WebSockets."
It's about designing a system that can handle state, synchronization, consistency, latency, failures and trust.
That's the part I find interesting.
And it's one of the reasons I'm continuing to develop StreetJS.
The goal isn't to hide these problems from developers.
It's to provide solid infrastructure so developers can spend more time building the actual application.
What would you build?
If you were building a multiplayer application with TypeScript today, what would you make?
A multiplayer game?
Collaborative editor?
Real-time trading simulator?
Online classroom?
Competitive quiz?
Something completely different?
I'm interested in hearing what other developers are building and what problems you've encountered with realtime Node.js applications.
StreetJS: https://github.com/hassanmubiru/StreetJS
Documentation: https://hassanmubiru.github.io/StreetJS/
TypeScript #NodeJS #WebSockets #Multiplayer #BackendDevelopment #OpenSource #JavaScript #SoftwareArchitecture