A Video Based AWS Certificate Training Platform Called Exam Pro

In this episode of Running in Production, Andrew Brown talks about how he and his team use Ruby on Rails to build an AWS certification training platform called Exam Pro. We talked about a huge range of AWS services and how they all come together to run and deploy his application.

They’ve gone all-in with AWS. Even their development environment is running on AWS using Cloud9 IDE. Exam Pro has been running in production since late 2018.

Topics Include

• 1:21 – A small team of developers actively work on the Exam Pro platform
• 2:40 – Motivation for using Ruby on Rails
• 4:52 – Would you use Rails again if you rewrote your app today?
• 5:21 – Monoliths are optimized for developer happiness not DevOps happiness
• 7:29 – Bypassing ActiveRecord to run raw SQL queries for database reads
• 8:19 – Using Rails Engines to break up the admin dashboard from the main app
• 9:22 – Trade offs for using 1 git repo vs multiple git repos
• 10:18 – Server side templates and a bit of JavaScript or an API back-end with lots of JS?
• 11:36 – Soon enough the front-end code will be completely separate and hosted on S3
• 12:02 – Pain points of using the asset pipeline and Rails specific build tools
• 13:57 – Action Cable is being used for something (but we don’t know what haha)
• 14:53 – Not using Sidekiq for background tasks, instead AWS SQS and the Ruby AWS SDK
• 16:47 – Docker is being used to run tests but not for dev and prod
• 18:38 – Cloud9 IDE is being used in development as an AWS based dev environment
• 20:03 – AWS Aurora is being used to manage a PostgreSQL database
• 21:01 – Your data is your most important asset, don’t leave it to chance
• 22:10 – A recap on what AWS SQS is and how it compares to Sidekiq, Resque or DelayedJob
• 23:26 – The main app responds back in 50-60 milliseconds without caching
• 25:29 – We never touch our servers, not even to SSH into them
• 26:40 – The Rails app is fronted by CloudFront and a load balancer, but not nginx
• 27:21 – SSL is terminated at the ELB level, not at each individual EC2 instance
• 28:27 – Comparing ELB to ALB and even NLB
• 29:07 – Strategies for migrating away from a monolithic application
• 29:59 – An S3 outage story that lead to using multi-region DNS fail over using Route 53
• 32:47 – What about error reporting, logging, monitoring and metrics?
• 35:27 – Sending transactional and campaign emails with SES and PinPoint
• 37:32 – Setting up 3rd party services with infrastructure as code tools is a huge win
• 39:24 – Sometimes there’s exceptions to the above, such as using Stripe to accept payments
• 41:08 – Configuration management on AWS with CloudFormation and Systems Manager
• 44:14 – They are using Amazon Linux 2 as their distro of choice
• 45:00 – Overall hosting costs less than $500 / month after all is said and done
• 45:49 – Zero down time deploys using blue / green deployments across 3 web servers
• 47:36 – Walking through a code deploy using various AWS resources and services
• 50:09 – Is is worth using managed services / mini-Heroku alternatives instead?
• 51:01 – Everyone Andrew knows who uses Heroku ends up leaving due to how pricey it is
• 52:20 – How do Rails database migrations get run?
• 52:42 – AWS really helps with database backups and disaster prevention / recovery
• 55:08 – Best tips and advice? Build a ton of apps and automate as much as possible
• 56:25 – You can find Andrew on Exam Pro, LinkedIn, YouTube, dev.to, GitHub and Twitter.

Links

📄 References

• https://en.wikipedia.org/wiki/Domain-specific_language
• https://en.wikipedia.org/wiki/Center_for_Internet_Security
• https://en.wikipedia.org/wiki/Application_performance_management
• https://en.wikipedia.org/wiki/Payment_Card_Industry_Data_Security_Standard

⚙️ Tech Stack

• rails →
• ruby →
• acm →
• aurora →
• aws →
• cloudformation →
• cloudfront →
• cloudwatch →
• codedeploy →
• datadog →
• docker →
• ecs →
• lambda →
• postgres →
• route53 →
• serverless →
• ses →
• sqs →
• stripe →
• websockets →

🛠 Libraries Used

• https://github.com/puma/puma
• https://github.com/ExamProCo/dilithium.js
• https://github.com/rails/webpacker
• https://aws.amazon.com/sdk-for-ruby/
• https://github.com/phstc/shoryuken

Support the Show

This episode does not have a sponsor and this podcast is a labor of love. If you want to support the show, the best way to do it is to purchase one of my courses or suggest one to a friend.

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