One thing I'd check on the "graceful exit in under 1 second" number. Tini forwards SIGTERM to Node, and Node with no handler just dies on it, so a fast exit can also mean in-flight renders got cut off a little more politely. Does index.js catch SIGTERM, stop taking requests and await the open conversions before browser.close()? Also curious whether you still need --no-sandbox now that chromium-sandbox is installed.