– A couple of hundred of developers committing to a monolithic app

– Motivation for choosing Pylons and Python

– Their service architecture can be described as a solar system

– Building their own NoSQL database called Edgestore before MongoDB existed

– Pylons is a micro-framework for Python

– Developing a custom payment handling system before Stripe existed

– How Dropbox stores your files on disk and who can access those files

– Back in 2014 Dropbox moved away from S3 to their own infrastructure

– Dealing with exabytes of storage

– A “multi mono repo” set up with millions of lines of Python

– The desktop client is a combination of Python and Rust

– Updating the desktop client code base from Python 2 to Python 3

– Pytest is being used for tests and Black for code formatting

– A developer can spin up their own Dropbox stack on a hosted dev server

– The web UI is mostly server rendered templates and a mix of React

– There’s a lot going on with MySQL, plus memcached and nginx / Envoy

– Using open source libraries created by Facebook and YouTube

– The open source version of nginx is being used a bunch

– Most things are hosted on their own data centers running Ubuntu

– There’s dedicated teams that focus on the infrastructure

– How code gets from a developer’s dev environment to passing in CI

– Once everything passes, it’s rolled out internally and then incrementally to users

– Feature flags are being used with a home grown solution

– Dealing with secrets using something they’ve developed in house

– Sometimes you end up building out a lot more than your core product

– Your files are very safely and securely backed up

– Monitoring, alerting, logging and error handling

– Rate limiting is handled at the app level along with memcached

– Best tips? Monoliths aren’t bad if you invest in them

– Think deeply about what you’re developing and focus on the architecture

– Utsav has a podcast at https://www.softwareatscale.dev, check it out!