Crypto Price Alert

Application diagram:

I opted out to overengineering this project in order to demonstrate some concepts and technologies. In order to do that, I followed some good practices, such as: Clean Architecture and SOLID principles

Assumptions

• One currency will be supported: USD
• Three coins will be supported: BTC, ETH, BNB
• Each job execution will notify the user about the price change

Running

• for run application asap you can use docker-compose, as the images have already been built and uploaded to docker hub:

    make docker_compose

• for build the application:

    make docker_build

Project's structure

📦price-alert-service
 ┣ 📂cmd
 ┃ ┣ 📂grpc
 ┃ ┃ ┣ 📂handler
 ┃ ┃ ┣ 📂pb
 ┃ ┃ ┣ 📂proto
 ┃ ┣ 📂rest
 ┃ ┃ ┣ 📂handler
 ┃ ┃ ┣ 📂presenter
 ┃ ┃ ┗ 📜api.go
 ┃ ┗ 📜main.go
 ┣ 📂docs
 ┣ 📂internal
 ┃ ┣ 📂application
 ┃ ┣ 📂domain
 ┃ ┗ 📂infra
 ┃ ┃ ┣ 📂config
 ┃ ┃ ┣ 📂db
 ┃ ┃ ┗ 📂repository
 ┣ 📂migrations

📦price-alert-job
 ┣ 📂cmd
 ┃ ┣ 📂app
 ┃ ┃ ┗ 📜app.go
 ┃ ┗ 📜main.go
 ┣ 📂internal
 ┃ ┣ 📂application
 ┃ ┣ 📂domain
 ┃ ┗ 📂infra
 ┃ ┃ ┣ 📂alert-service
 ┃ ┃ ┣ 📂config
 ┃ ┃ ┣ 📂crypto-compare
 ┃ ┃ ┣ 📂kafka
 ┃ ┃ ┗ 📂notification-broker

📦notification-service
 ┣ 📂cmd
 ┃ ┣ 📂app
 ┃ ┃ ┣ 📜app.go
 ┃ ┗ 📜main.go
 ┣ 📂internal
 ┃ ┣ 📂application
 ┃ ┣ 📂domain
 ┃ ┗ 📂infra
 ┃ ┃ ┣ 📂config
 ┃ ┃ ┗ 📂gomail-email-service

Code quality

• golangci-lint
• unit testing

TODO's

• Implement DLQ (Dead Letter Queue)
• Finish graceful shutdown implementation
• Implement better api error treatment
• Implement better test coverage
• Make documentation available
• To be production ready, must follow 12-factor app, such as:
  • separate codebase (the three projects)
  • create script for database migration
  • change the price alert job to be as a one-time execution, using kubernetes job scheduler as an example