A Custom Electronic Medical Record System for an Ophthalmology Clinic

Running in Production

In this episode of Running in Production, Jason Swett goes over building an internal medical record system with Ruby on Rails. It’s hosted on AWS using Kubernetes and it’s been up and running since 2019.

Jason talks about replacing a few 3rd party services with 1 custom solution, using custom generators, embracing PORO, transitioning from Ansible and individual servers to Kubernetes, making safe decisions while learning as you deploy new things and much more.

Topics Include

• 1:14 – The dream is to replace 9 separate systems with 1 custom solution
• 3:02 – Deploying on day 1 and what exactly is an EMR?
• 6:20 – Motivation for choosing Ruby on Rails to build a medical system
• 10:39 – Infrastructure as code is important
• 13:36 – The app does scheduling and soon emails will be sent to patients
• 15:29 – Specific things the app does and how Rails helps Jason accomplish them
• 21:56 – Custom generators are used for different modules
• 25:11 – Every 5 seconds certain forms are auto-saved and a few gems that are being used
• 27:56 – Rails can only help you so much, then you’re kind of on your own
• 34:10 – Making a distinction between imperative and declarative code
• 36:36 – Server rendered templates with sprinkles of Javascript (StimulusJS)
• 43:53 – Looking into using Hotwire Turbo in the distant future
• 45:41 – Migrating to use Elasticsearch and using it over PostgreSQL’s full text search
• 47:49 – Using AWS for hosting and landing on using Kubernetes with EKS
• 52:57 – 5% of Jason’s brain is taken up at all times knowing he’s on-call
• 55:22 – Switching from individual servers with Ansible to Kubernetes
• 59:37 – Using eksctl and Helm to move towards infrastructure as code
• 1:06:12 – The deploy process from development to production with Kubernetes
• 1:09:53 – Using feature flags and code reviews
• 1:11:35 – Handling database migrations with a load balanced application
• 1:15:13 – A strategy for writing Jira tickets
• 1:17:53 – RDS snapshots are handling database backups
• 1:21:14 – Monitoring, alerting and the idea of “sharpening the saw”
• 1:25:47 – Best tips? Make safe decisions and improve skills such as reading documentation
• 1:30:44 – Check out Jason’s site at https://www.codewithjason.com/

Links

📄 References

• https://twitter.com/dhh (Creator of Rails)
• https://en.wikipedia.org/wiki/Electronic_data_interchange
• Jason’s podcast where Nick was a guest talking about freelancing, Docker and Kubernetes
• https://rtpg.co/2021/06/07/changes-checklist.html (Database migration steps)
• https://nickjanetakis.com/blog/learning-a-new-web-framework-with-question-driven-development
• https://www.codewithjason.com/best-programming-tips/

⚙️ Tech Stack

• rails →
• ruby →
• ansible →
• aws →
• eks →
• elasticache →
• elasticsearch →
• kubernetes →
• nginx →
• postgres →
• rds →
• redis →
• s3 →
• stimulusjs →

🛠 Libraries Used

• https://github.com/mperham/sidekiq
• https://github.com/heartcombo/simple_form
• https://github.com/weaveworks/eksctl
• https://helm.sh/

Support the Show

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