Scaling Dropbox: from 4k to 40 million

Scaling lessons learned at Dropbox: from 4k to 40 million

UTC

Keep everything in UTC internally! Server times, stuff in the database, etc. This will save lots of headaches, and not just daylight savings time. Some software just doesn’t even handle non-UTC time properly, so don’t do it! We kept a clock on the wall set to UTC. When you want to display times to a user, make the timezone conversion happen at the last second.