Rethinking Latency: How We Traded Cold Starts for Consistency
Article summary
When we first migrated to AWS API Gateway and Lambda, we knew cold starts might be an issue-but we underestimated how much they would shape the user experience. For months, we chased latency as if it were a singular metric. We measured p95s, tuned timeouts, and optimized function packaging. But something always felt off. Users weren’t frustrated by the occasional spike-they were frustrated by the unpredictability. That’s when we shifted focus. Instead of minimizing cold starts at all costs, we started designing for consistency. Where Cold Starts Became a Problem Cold starts weren’t catastrophic. They were subtle. A request might take 200ms one moment, then 1.5s the next-same user, same endpoint, no obvious pattern. The result was distrust. Users didn’t feel the system was slow; they felt it was unreliable.
Read Full Article on MediumPractical takeaway
The main idea behind Rethinking Latency: How We Traded Cold Starts for Consistency is to help teams move from broad theory to clear, repeatable decision making. When teams apply this thinking, they reduce ambiguity and focus on improvements that deliver measurable momentum.
Example scenario
Imagine a team facing competing priorities. By applying the ideas in Rethinking Latency: How We Traded Cold Starts for Consistency, they can map dependencies, identify risks and choose the next move that produces progress without destabilizing their system.
Common mistakes to avoid
- Trying to redesign everything instead of taking small steps.
- Ignoring real constraints like incentives, ownership or legacy systems.
- Creating documents that do not lead to any change in code or decisions.
How to apply this in real work
Start by identifying where Rethinking Latency: How We Traded Cold Starts for Consistency already shows up in your architecture or delivery flow. Then pick one area where clarity would reduce friction. Apply the idea, measure its effect and share the learning.
Signs you are doing it correctly
- Teams make decisions faster and with fewer disagreements.
- Architectural conversations become clearer and less abstract.
- Changes land safely with fewer surprises or rework cycles.