If the first load takes several minutes instead of ~30 s on Microsoft Edge, Edge's Enhance your security on the web setting is disabling the WebAssembly JIT compiler on this site. Microsoft documents this behaviour and explicitly recommends the workaround — quoting the page:
Developers should be aware that the WebAssembly (WASM) interpreter running in enhanced security mode might not yield the expected level of performance. We recommend adding your site as an exception to opt-out of enhanced security mode for site users.
To add the exception: open edge://settings/privacy → Security → Manage enhanced security for sites → under Never use enhanced security for these sites, click Add a site and enter https://datalab-platform.com (or your deployment URL). Reload the page; load time drops back to ~30 s. Chrome, Firefox and Safari are not affected.
By default DataLab-Web runs its Pyodide runtime in a Dedicated Web Worker, which keeps the UI responsive during heavy work. If you suspect a worker-specific problem (the app hangs at boot, a processing never returns, or you are debugging the runtime), you can fall back to the original in-thread runtime by appending ?runtime=main to the URL — for example https://datalab-platform.com/?runtime=main. The choice is also honoured from localStorage["datalab-web:runtime"] = "main" and, at build time, from VITE_RUNTIME_WORKER=0. Both topologies expose the exact same features; the in-thread mode is a backup, not the nominal configuration. Use ?runtime=worker to force the default back.