AWS Lambda vs a Small VPS: When to Choose Which
🎯 The Trade-off
Lambda is serverless and scales automatically. A VPS is predictable and cheap. Which should you choose?
✅ When Lambda Wins
1. Sporadic Traffic
If your app gets traffic in bursts, Lambda is perfect. You pay only when it runs. A VPS costs money even when idle.
2. Simple Functions
Lambda excels at simple, stateless functions: API endpoints, image processing, scheduled tasks. If it's a single-purpose function, Lambda fits.
3. No Ops Overhead
Lambda handles scaling, patching, and infrastructure. You just write code. For small teams, that's valuable.
✅ When a VPS Wins
1. Steady Traffic
If you have consistent traffic, a VPS is cheaper. $5/month gets you a small VPS that can handle moderate traffic. Lambda would cost more.
2. Long-Running Processes
Lambda has timeout limits (15 minutes max). If you need long-running processes, background jobs, or WebSocket connections, use a VPS.
3. Predictable Costs
VPS costs are fixed. Lambda costs scale with usage. If you want predictable bills, VPS is simpler.
4. Full Control
Need to install specific software, use custom binaries, or have full root access? VPS gives you that. Lambda is more constrained.
💰 Cost Comparison
For low traffic (under 1M requests/month):
- Lambda: ~$0.20/month (free tier covers most)
- VPS: $5/month (fixed cost)
For moderate traffic (10M requests/month):
- Lambda: ~$20/month
- VPS: $5/month
For high traffic (100M+ requests/month):
- Lambda: ~$200/month
- VPS: $20–40/month (bigger instance)
💡 My Rule of Thumb
Start with a VPS if:
- You have steady traffic
- You want predictable costs
- You need full control
Use Lambda if:
- Traffic is sporadic
- You're building simple functions
- You want zero ops overhead
💭 My Take
Lambda isn't always better. For many apps, a small VPS is simpler, cheaper, and more flexible.
Don't default to serverless. Choose based on your actual needs, not the hype.