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Modal Blog·· 2026-06-22AI score36

Modal explains why sandbox "started" ≠ "ready" and how warm pools cut perceived startup latency

Unpacking sandbox startup latency: why started ≠ ready

AI summary

Modal argues that container scheduling and boot time, which most sandbox benchmarks measure as time to interactive, is the smallest part of what users actually wait through; application-level setup after the container starts often takes multiple seconds. Modal is making Readiness Probes generally available to signal when a sandbox has finished initializing, and recommends warm sandbox pools built on modal.Queue plus Directory Snapshots to move setup off the user's critical path.

Source:Modal Blog · modal.com