Sticky sessions seem convenient but create problems:
Uneven load: Heavy users stick to one server
Failover pain: When a server dies, all its sessions die too
Scaling difficulty: New servers don't help existing users
Better alternatives:
- External session store (Redis): Any server can access any session
- Stateless tokens (JWT): Session data travels with each request
- Client-side state: Browser stores session in cookies
Use sticky sessions only for legacy apps you can't modify. Build new apps stateless.