Crypto Coding Challenge

Backend

The tech stack is mostly InversifyJS running under Express with a few other small libraries, and it follows a scheme first approach for the Postgres DB.

The only controversial tech used was Bun for the JavaScript engine and testing, as it's just reached its 1.0 release. It was mostly a very enjoyable experience with my only negative issues around the testing framework still lacking features.

All the endpoints have their inputs validated with Joi.

I decided to use a stored procedure starting a transaction in order to guarantee that no tocos can be lost in the wild during a transfer.

Most endpoints are tested, I would have handled more scenarios if I could spend more time.

The architecture is based on the SOLID principles in order to expand the server's functionalities easily

Frontend

The frontend is React, Flowbite React with a few other libraries.

I spent a lot less time on the frontend than I did on the backend and as such didn't make as much progress as I would have liked but it's in a working state.

Missing / Improvements

Given I tried to match the time given and mostly focused on the backend, the front is lacking quite a few features

• Some types are duplicated in the front/back, ideally there should be a shared library where they should be in
• Backend has validation but Front End is not reusing these errors
• I don't like how I'm passing around the repositories from the controllers, I would have added DI
• the module.ts from the API should be fed all the controllers at once
• I could have added code generated API documentation
• Server routers with decorators would have been clearer and cleaner
• Front-end validation missing, no refetch after queries
• A lot of UI/UX changes on the front : pre-select dropdowns, access resources by url,...

In the end, I found it quite hard to produce clean and quality code given the time allotted but I think the result is pretty good considering the time given

Dependencies

• Docker

Development dependencies

• Bun

Running

docker compose -f docker-compose.cmd.yml up server --abort-on-container-exit --build

You can then access the Dashboard interface at http://localhost:5000

You can then access the API interface at http://localhost:4040

Tests

You can run the project and its tests under docker with the following:-

Runs backend and frontend tests.

docker compose -f docker-compose.cmd.yml  -f docker-compose.test.yml up --abort-on-container-exit --build

This will build a local docker image of the projects and also run the postgres image.

Backend

For just the backend test:

docker compose -f docker-compose.cmd.yml  -f docker-compose.test.yml up server --abort-on-container-exit --build

Frontend

For just the frontend test:

docker compose -f docker-compose.cmd.yml -f docker-compose.test.yml up dashboard  --abort-on-container-exit --build

Local Development

You can run a local copy of postgres which will also be created with the schema using the command:

docker compose  up

Install Bun

curl -fsSL https://bun.sh/install | bash

From the root ./ run:-

bun install

Backend

Then from within the ./packages/server folder, you can run:-

bun run start

You can then access the API interface at http://localhost:4040

Frontend

Then from within the ./packages/dashboard folder you can run:

bun run start

You can then access the Dashboard interface at http://localhost:3000

• 2 Users are already created

• You can add new users or transfer Tocos from different users

Build / Publishing

When publishing dashboard, it gets copied into the the public folder of the server. This way you can run a single docker image with everything being served by Express.