HTTP Based API that sends emails through different providers to prevent downtime.

• NodeJS 12
• Typescript
• ExpressJS

I chose this stack because it works well for this type of microservices and I'm also familiar with it. I like how the language (Javascript/Typescript) and platform (NodeJS) evolved over the past few years. There are also mature libraries / frameworks by now and the community keeps growing. It also has better developer experience compared to technologies like Java.

ExpressJS is the most popular micro framework for NodeJS, but I could also have used Koa or something more oriented to building APIs like Hapi.

Typescript is a big improvement to the stack because it adds robustness and mantainability to the application. It may be harder to setup but it improves the dx: makes the code easier to read, write (better autocomplete) and refactor, besides adding documentation.

Check technical / architectural decisions document for more details

1. Install dependencies

npm i

2. This project uses dotenv so you'll need to create an .env file with the configurtion. Use .env.example as reference.

Note: provider number defines priority

3. Start the server in dev mode

npm run dev

Using docker and docker-compose you can easily recreate the environment:

• NodeJS server
• Swagger UI
• PostgreSQL

1. Open docker-compose.yml and edit the env variables accordingly.

Note: provider number defines priority

2. Install dependencies and build the app

npm i
npm run build

3. Start the application

docker-compose up

The application is exposed on port http://localhost:3000 by default and swagger ui on http://localhost:9999

The tests are implemented in jest. To run them:

npm test

Code style is enforced with prettier and linting is done by tslint. To run it manually:

npm run lint

OpenAPI was used to document the API. It is exposed on http://localhost:3000/api-docs to be consumed by swagger-ui

Two endpoints are exposed as reference:

• /status/health - to check availability
• /status/config - to expose the config