README
¶
faang-stonks
No affiliation with, but inspired by r/Superstonks.
Requirements
- Create a REST API where clients can retrieve stock data for FAANG companies
- Optionally, clients can request historical data for one or more stocks
- Service should update stock prices every N minutes where N is configurable
- Service and supporting services (e.g., database, web layer, etc.) should be packages with Dockerfiles, and a docker-compose.yml file allowing full application instantiation.
- Use git for version control and frequently commit changes.
Motivation
This project is my attempt to find a happy medium between scalable, simple, flexible, simple, readable (i.e., not clever to the point of illegible code), secure, and simple. Simple's the hard part.
Discussion
The project's requirements don't specify the scale at which this service should operate. As such, I took my usual approach: keep things simple yet flexible to meet future requirements without the need for a complete code refactor.
For example, SQLite isn't the best choice for time-series data storage at scale, but it's good enough for this MVP in the absence of detailed scale requirements. I've included a stub for InfluxDB to illustrate how I could add support for it without affecting the rest of the code. I also included an in- memory implementation.
You'll find a similar pattern for financial data providers. I define an interface the rest of the code consumes, and then add an implementation of that interface for my financial data provider (IEX Cloud in this case).
API Resources
The API exposes two endpoints: one for retrieving all stocks and another for
requesting quotes of a specific stock symbol. The API endpoints are versioned
with v1.
- GET /v1/stocks
- GET /v1/stock/[symbol]
All timestamps returned by the API are in UTC.
Last N Quotes
Each API endpoint allows for an optional parameter last that will direct the
API to return the last n quotes, or the maximum observed quotes, whichever
is less.
GET /v1/stocks
Example: http://localhost:18081/v1/stocks
Response body:
{
"aapl": [
{
"price": 130.4,
"symbol": "aapl",
"time": "2021-05-07T19:31:07.000000272Z"
}
],
"amzn": [
{
"price": 3296.16,
"symbol": "amzn",
"time": "2021-05-07T19:31:07.000000623Z"
}
],
"fb": [
{
"price": 320.125,
"symbol": "fb",
"time": "2021-05-07T19:31:05.000000929Z"
}
],
"goog": [
{
"price": 2402.14,
"symbol": "goog",
"time": "2021-05-07T19:30:21.000000201Z"
}
],
"nflx": [
{
"price": 504.08,
"symbol": "nflx",
"time": "2021-05-07T19:31:00.000000053Z"
}
]
}
GET /v1/stock/goog
Example: http://localhost:18081/v1/stock/goog
Response body:
[
{
"price": 2403.06,
"symbol": "goog",
"time": "2021-05-07T19:32:08.000000511Z"
}
]
GET /v1/stock/fb?last=3
Example: http://localhost:18081/v1/stock/goog?last=3
Response body:
[
{
"price": 320.12,
"symbol": "fb",
"time": "2021-05-07T19:36:02.000000631Z"
},
{
"price": 319.92,
"symbol": "fb",
"time": "2021-05-07T19:35:09.000000338Z"
},
{
"price": 319.99,
"symbol": "fb",
"time": "2021-05-07T19:34:08.00000012Z"
}
]
Documentation
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There is no documentation for this package.
Source Files
Directories
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| Path | Synopsis |
|---|---|
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Package api provides a HTTP(S) server that serves a REST API that serves financial data for a subset of stock symbols.
|
Package api provides a HTTP(S) server that serves a REST API that serves financial data for a subset of stock symbols. |
|
Package cmd adds command line support to this application.
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Package cmd adds command line support to this application. |
|
Package finance provides interfaces and types for financial data services.
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Package finance provides interfaces and types for financial data services. |
|
iexcloud
Package iexcloud provides a finance.Provider implementation that retrieves its data from IEX Cloud's API.
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Package iexcloud provides a finance.Provider implementation that retrieves its data from IEX Cloud's API. |
|
Package history provides interfaces and types for objects that store store a retrieve historical financial data.
|
Package history provides interfaces and types for objects that store store a retrieve historical financial data. |
|
influxdb
Package influxdb provides history.Archiver and history.Provider implementations that use the time series database, InfluxDB.
|
Package influxdb provides history.Archiver and history.Provider implementations that use the time series database, InfluxDB. |
|
memory
Package memory provides history.Archiver and history.Provider implementations that use RAM for volatile storage.
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Package memory provides history.Archiver and history.Provider implementations that use RAM for volatile storage. |
|
sqlite
Package sqlite provides history.Archiver and history.Provider implementations that use SQLite for storage.
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Package sqlite provides history.Archiver and history.Provider implementations that use SQLite for storage. |
|
Package metrics provides instrumentation for the rest of the application, and the requisite HTTP server to serve the Prometheus endpoint separate from the REST API endpoint.
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Package metrics provides instrumentation for the rest of the application, and the requisite HTTP server to serve the Prometheus endpoint separate from the REST API endpoint. |
|
Package poll provides a poller that retrieves financial data for the given stock symbols at the given interval and updates the archiver with the results.
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Package poll provides a poller that retrieves financial data for the given stock symbols at the given interval and updates the archiver with the results. |