Fine-Grained Sandboxing With V8 Isolates

In an ideal world, code would always run as close as possible to the things with which it communicates -- end users, storage, external APIs, etc. However, most software stacks are only cost-effective if applications are long-running, handling many events in one place. We need a new approach that can efficiently load code to handle just one event, so that it can be executed wherever is best for that one event, across a distributed network.

Kenton Varda explains how Cloudflare solved this problem by building a compute platform using V8 isolates instead of containers or VMs, achieving 10x-100x faster cold starts and lower memory footprints. We'll go through technical details of embedding V8, distributing code, scheduling isolates, resource management, and security risks.