https://github.com/naartjie/bitfinex-codingchallenge

https://github.com/naartjie/bitfinex-codingchallenge

Last synced: 21 days ago
JSON representation

• Host: GitHub
• URL: https://github.com/naartjie/bitfinex-codingchallenge
• Owner: naartjie
• Created: 2024-03-02T09:53:52.000Z (9 months ago)
• Default Branch: main
• Last Pushed: 2024-03-02T17:08:23.000Z (9 months ago)
• Last Synced: 2024-04-16T01:24:39.409Z (7 months ago)
• Language: JavaScript
• Size: 20.5 KB
• Stars: 0
• Watchers: 1
• Forks: 0
• Open Issues: 0
• Metadata Files:
  • Readme: README.md

Awesome Lists containing this project

README

        
# Installing and Running

```sh

npm install

# start 2 grape instances

npm run grapes

# run as many nodes/peers as you want

node ./src/peer.js

```

# Implementation

This takes a very basic approach in order to achieve proof-of-concept. Each peer has an orderbook which is versioned. An order can only be placed if you have the latest version. If any peers have a version higher than yours, it means they have already accepted an order and you need to update your orderbook before placing an order. This isn't ideal "at scale", but it's basic enough to implement in a day, and does the job for the sake of this exercise.

## Limitations and issues

If a peer stops and is restarted (on a different port), grape doesn't "drop it". Need to look into why/what's wrong. Right now I'm re-running `npm run grapes` command and it's not great DX.

### Orderbook

It's a very simplistic implementation. The whole orderbook is stored as a JS object. Storage / perf would be an issue.

The prices are stored "as is", it would make sense either store cents as whol integers or alternatively use a currency number type from an npm lib.

This implementation doesn't strictly update the local orderbook - it does so through the p2p mechanism by sending ourselves the same `create_order` message. We could simplify that by doing that update in place, and ignoring or not sending the create_order message to ourselves.

# Next steps

### Features

Currently the creating of a new order is hardcoded in the `./src/peer.js`. I'd like to extend it to read `stdin` and be able to process commands such as:

```

buy 100 10

buy 105 7

buy 110 4

```

Add ability to cancel orders - need order.peer_id, so can only cancel our own orders

### Security

Defensive programming -> fail early for invalid inputs (for example payload.command)

doesn't deal with bad actor peers

### Perf

Streamlining placing orders and distributing orderbook updates. This is a