Cloud bills can creep up on you — especially in serverless environments, where costs scale automatically with usage. AWS Lambda, API Gateway, and S3 are amazing tools for building scalable, low-maintenance apps. But used carelessly, they can burn through your budget.
In this post, I’ll walk you through proven techniques to cut serverless costs without compromising performance or scalability.
🔄 1. Right-Size Your Lambda Functions
AWS charges for memory and duration, so over-provisioning either leads to waste. Here’s how to right-size:
- Use AWS Lambda Power Tuning to find the best memory-performance tradeoff
- Benchmark common workloads and adjust memory in 64MB increments
- Lower the timeout unless your function truly needs to run long
Pro tip: Higher memory = more CPU = potentially faster execution (and lower cost!)
🧲 2. Minimize Cold Starts
Cold starts can slow performance and increase execution time (and cost). Here’s how to reduce them:
- Use provisioned concurrency for latency-critical functions (watch out for added cost)
- Keep deployment packages small (less init time)
- Use Node.js or Python over Java if latency is key
💳 3. Cut API Gateway Costs
API Gateway can rack up fees quickly if you serve lots of traffic. Save money by:
- Using HTTP APIs instead of REST APIs (up to 70% cheaper)
- Enabling caching for frequently accessed endpoints
- Moving high-throughput, low-complexity APIs to ALB + Lambda targets
🚫 4. Avoid Unnecessary Invocations
This is one of the most overlooked issues. Ask yourself:
- Is your Lambda triggered too often (e.g. from noisy S3 event notifications)?
- Can logic be filtered upstream (e.g. S3 event filter rules)?
- Can a single batch replace multiple granular invocations?
🔢 5. Leverage S3 Storage Classes
S3 is cheap, but there’s room to optimize:
- Move infrequently accessed data to S3 Intelligent-Tiering or Glacier
- Set up lifecycle policies to automatically transition or delete objects
- Compress large assets before storing or transferring
⚖️ 6. Monitor and Visualize with Cost Explorer + CloudWatch
You can’t optimize what you can’t see. Use:
- AWS Application Insights to group and monitor related resources more easily — giving you a centralized view of performance and cost behavior across services
- AWS Cost Explorer to track spending trends
- CloudWatch Logs Insights to audit function behavior and duration
- CloudWatch Dashboards for live views of Lambda performance
📆7. Plan for Savings with Compute Savings Plans
If you’re using Lambda consistently, consider:
- Purchasing a Compute Savings Plan (1 or 3 years) to lock in lower prices
- This applies to Lambda, Fargate, and EC2 — great for mixed architectures
🌟 Final Thoughts
Cost optimization doesn’t mean cutting corners. With smart tuning, lifecycle policies, and visibility, you can run a production-grade AWS serverless stack that’s both powerful and budget-conscious.
What tips did I miss? Let me know in the comments!