For the backend portion of the test we'd like you to write some code that achieves the following:
- Create a JSON API (REST or GraphQL) using Node.js which will return which cryptocurrency exchange we should use to buy a given amount of Bitcoin to minimize the amount of USD or USDT we'll spend on this trade.
Example API call (for 1 BTC):
curl http://localhost:4000/exchange-routing?amount=1
Example API response (if Coinbase price of $10,000 / BTC is the cheapest):
{
"btcAmount": 1,
"usdAmount": 10000,
"exchange": "coinbase"
}
- You'll need to compare Binance and Coinbase order books and compute the best execution price for the given amount of Bitcoin we want to buy. (You can assume that 1 USDT = 1 USD at all time.)
- [Bonus] Add a third exchange to compare with Binance and Coinbase.
Feel free to structure the code however you prefer and use third-party libraries at your discretion.
NOTE: Please make the server listen on port :4000.
- Crypto Trading 101: How to Read an Exchange Order Book
- Binance Order Book API Endpoint
- Coinbase Order Book API Endpoint
Note that both APIs above are public and don't require any authentication.
Answer the questions in the FOLLOW-UP.md file.
The test contains a basic docker-compose.yml file. It uses the latest official NodeJS
Docker image and creates a container for the backend service.
The respective folder is mounted in /app directory inside the container.
It isn't a requirement to use it, but may be convenient.
NOTE: We WILL run your code inside this container.
Once you've completed the test, please compress your files (via zip or tar) and return them as a link or email attachment in reply to your test invite. We'd like the code in your submission to remain private, so please avoid committing or pushing the code publicly.
Do not include node_modules or .git in your submission
Once we receive it, a member of our team will review and we'll get back to you as soon as possible.
Thanks!