Tibica: Serverless Latency Optimization

The Customer and The Challenge

Tibica is a serverless application marketplace offering cloud-native tools for teams that want to skip infrastructure management. Their product line covers headless content management, code versioning, and access control, all built on AWS Lambda and designed to scale without dedicated servers.

In August 2023, Tibica reached out to Perfsys with a specific problem. Their Lambda functions were doing their job — scaling on demand, keeping costs predictable — but response times were slow. Lambda cold starts were adding nearly two seconds of delay to multiple workflow steps, and users were feeling it.

Tibica's setup at the time routed all requests through an API Gateway to Lambda integration, with a custom Lambda authorizer handling access control. Functional, but not fast.

The Solution

Perfsys started with a full analysis of Tibica's application workflows using AWS X-Ray , mapping exactly where time was being lost. The finding was clear: the majority of requests were simple GET operations with no complex processing logic. They didn't need Lambda at all.

The fix was to bypass Lambda entirely for those operations and query DynamoDB directly through AWS API Gateway using Velocity Template Language (VTL). VTL lets API Gateway communicate with DynamoDB without invoking a Lambda function, which eliminates cold start latency at the source. The same approach was applied to straightforward PUT and POST operations.

No infrastructure was rebuilt. The change was at the integration layer.

Results

The impact was immediate across all measured metrics.

GET response times dropped by 65%, from 1.74 seconds to 0.61 seconds. Write operations improved from 2.69 seconds to 1.99 seconds. The average user workflow duration halved from 42.8 seconds to 20.4 seconds. And with fewer Lambda invocations, compute costs fell by 50%.

Conclusion

Cold starts are a well-known serverless trade-off, but they're not always unavoidable. For requests that don't require business logic, bypassing Lambda and querying the database directly is a faster and cheaper pattern. The key is knowing which requests those are — and that's what the AWS Cloud Assessment surfaced for Tibica.

This was the second optimization Perfsys carried out for Tibica. You can read about the first one — migrating Lambda functions from x86_64 to arm64 for a 17% performance gain and 20% cost reduction — in the AWS Performance Optimization case study . And to see how the full Tibica platform was built from the ground up, visit the Serverless Cloud Marketplace case study .

Seeing slow response times in your serverless application?

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Anastasiia Tokareva

Software Engineer