You're using the built-in debugging server, which does not handle concurrent requests. To use something standalone, that's a bit more robust, use uwsgi: zm

You're using the built-in debugging server, which does not handle concurrent requests. To use something standalone, that's a bit more robust, use uwsgi: zmusic-ng $ uwsgi --chdir backend/ -w zmusic:app --http-socket 0.0.0.0:5000 I've updated the README to reflect this suggestion: http://git.zx2c4.com/zmusic-ng/about/#standalone http://git.zx2c4.com/zmusic-ng/about/#standalone