They did move their writes to an async job. They write the apps list into mongodb, then a daemon later copies it into mysql. Mongodb is being used as a cache (t

They did move their writes to an async job. They write the apps list into mongodb, then a daemon later copies it into mysql. Mongodb is being used as a cache (the frontend queries mongo then mysql)... this way they can read the data while also throttling writes to their main db.