In this episode of Running in Production, Dash Winterson talks about building a new type of chat app for iOS using Django and Python on the back-end. It’s hosted on AWS using Elastic Beanstalk and has been up and running since mid 2020.

Dash covers creating async compatible code in Django, developing a monolithic back-end that a few developers develop against, investing in the AWS ecosystem, end to end message encryption and the Zen of Python.

Topics Include

• 3:05 – Rewriting an existing Django app into a new Django app with 90%+ test coverage
• 8:49 – Async features in Django and not using Celery
• 12:07 – A breakdown of gRPG and Protobuff
• 15:13 – The platform has about 300 daily active users, dead locks and monitoring
• 17:47 – A monolithic Dockerized app with 4 developers working on the project
• 20:05 – There’s only an API back-end in Django, the front-end is a native iOS app
• 22:51 – The SimpleJWT and Redis / ARedis libraries were very helpful in Python
• 27:04 – The phonenumbers library showed to be very useful too
• 30:02 – Using Docker Compose in development with a multi-stage Dockerfile
• 32:22 – Using Elastic Beanstalk in production and a number of other tech choices
• 38:06 – There’s no configuration management tools being used, but that’s next
• 42:09 – Most AWS instance types they are using are medium size
• 44:00 – The process to deploy code from development to production
• 49:20 – Dealing with backing up user generated data and encrypting messages
• 54:06 – Getting alerted of errors through Slack and email
• 58:01 – Best tips? When in doubt stick to the Zen of Python
• 1:00:53 – You can find Dash on GitHub and Twitter

Links

• https://en.wikipedia.org/wiki/Protocol_Buffers
• https://www.elastic.co/observability
• https://python-poetry.org/
• https://www.python.org/dev/peps/pep-0020/ (The Zen of Python)

• django →
• python →
• swift →
• aws →
• circle-ci →
• docker →
• elasticache →
• nginx →
• rabbitmq →
• rds →
• redis →
• route53 →
• sentry →
• slack →
• terraform →

• https://github.com/encode/django-rest-framework
• https://grpc.io/docs/languages/python/basics/
• https://developer.apple.com/metal/
• https://github.com/SimpleJWT/django-rest-framework-simplejwt
• https://github.com/andymccurdy/redis-py
• https://github.com/NoneGG/aredis
• https://github.com/daviddrysdale/python-phonenumbers
• https://github.com/theskumar/python-dotenv

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