SkyPilot Sandboxes is a bring-your-own-cloud (BYOC) code execution layer that runs isolated, LLM-generated code in Kubernetes pods on your own infrastructure. A single cluster can sustain 50,000+ concurrent sandboxes with sub-second launch times via warm pools. The post includes a full RL post-training example using sandboxed reward scoring, a Python async SDK walkthrough, and head-to-head benchmarks against Modal showing ~20% faster p50 latency and up to 10x cost reduction. Code and data never leave your cloud, and secrets are injected at runtime rather than baked into images.
Table of contents
What is a sandbox, and why do you need one? #SkyPilot Sandboxes run on your own infra #Example: RL-training a code-generation model, with sandboxed reward #Competitive with Modal, on your own clusters #Takeaways #833 Impressions