Building with purpose: Stories from the Now Go Build CTO Fellows

AllApr 22, 2026

The invisible engineering behind Lambda’s network

Here's a 3-sentence summary of the engineering blog post: AWS Lambda's network team optimized the platform's networking infrastructure to reduce latency and enable serverless workloads. They solved the VPC cold start problem by rewriting Geneve tunnel headers using eBPF, reducing latency from 150 milliseconds to 200 microseconds and removing a fundamental blocker for high-density microVMs. This innovation paved the way for Lambda SnapStart, which further reduced cold start times by cloning pre-initialized execution environments and required the team to reimagine their network topology to support isolated network namespaces for concurrent invocations.

Distributed SystemsArchitectureCloud

1 min

Building with purpose: Stories from the Now Go Build CTO Fellows

The invisible engineering behind Lambda’s network

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