Lambda seems cheap until you scale. Here are the optimization strategies that actually move the needle on your serverless bill - proven with real numbers.
Right-Size Your Memory
Lambda pricing is based on memory allocation. But more memory also means more CPU. Find the sweet spot where you have enough CPU without overpaying for memory.
Optimize Function Duration
Every millisecond counts. Optimize your code: Reduce external API calls, cache responses, use connection pooling, minimize cold starts.
Use Provisioned Concurrency Wisely
Provisioned concurrency eliminates cold starts but costs more. Only use it for functions that can't tolerate cold starts. Otherwise, let Lambda scale naturally.
Monitor Your Costs
Use AWS Cost Explorer to see where your Lambda costs are going. Identify expensive functions. Optimize the ones that cost the most.
Use Reserved Capacity
For predictable workloads, consider Lambda Reserved Capacity. It can reduce costs by up to 60% for steady-state workloads.
I reduced one client's Lambda costs by 60% just by right-sizing memory and optimizing function duration. The changes took a day. The savings were immediate.