For this assignment, you will build a backend web service that enables users to publish posts and subscribe to other users posts. Pretend like Embed devs should be able to integrate with your backend web service and run it inside our infrastructure.
To complete this assignment you will require the following:
- Python >= 3.8
- any Python web framework e.g. Flask, Bottle, CherryPy, Tornado, Django, FastAPI (it's recommended to pick the one you feel most comfortable with)
- any data store for storing the data models and user data e.g. PostgreSQL, MariaDB, MongoDB, Cassandra, CouchDB, Riak, Redis, Memcached (it's recommended to pick the one you feel most comfortable with)
- private GitHub or Bitbucket account and public git repository where you will upload the code
- use RESTful or GraphQL or gRPC (the choice is yours) to implement the APIs
- User is able to register by selecting a username and password
- User may not register if the username is already taken
- User may not register if the password is not strong enough (define some rules e.g. minimum 10 characters, a mix of letters, numbers and special characters)
- After registration is complete, user should receive an authorization token to use
- User can't log in if the username and password are not correct
- After the login is complete, the user should receive an authorization token to use
- User can publish a post at any time, post must have a title (e.g. up to 100 characters long) and post text can be only up to 1000 characters long
- User can view his/her posts at any time, sorted from the most recent one to the least recent one
- User can search his/her posts by the title name via a simple substring match (e.g. searching "sport" should return any post titles such as "The best sporting events in town", "Scream SPORT if you like it", "Sport in everyday life")
- User can search his/her posts by date published via start date and end date filters (e.g. return all posts between 10/07/2022 and 21/07/2022 where both start date and end date are inclusive), only date is taken into account (not the time of the posting)
- If the user didn't provide a start date, it implies all the posts from the beginning of time until the end date (included)
- If the user didn't provide an end date, it implies all the posts from the start date (included) until now
- User can update the following parts of his/her profile: short biography, birth date, country, city, list of interests
- User can view how many subscribers he/she currently has
- User can view how many subscriptions he/she currently has
- User can view how many posts he/she currently has
- User can view all the other usernames available, view their profile info, how many subscribers they currently have and their last 5 posts
- User can view the most popular usernames available (top 20 users), view their profile info, view how many subscribers they currently have and their last 5 posts (popularity can be determined by a simple formula: total number of subscribers plus the total number of posts, the more you have the more popular you are, but feel free to define popularity in any way you find applicable)
- User can subscribe to any other user simply by adding their username to the list of subscriptions
- User can't subscribe to a username that doesn't exist
- User can remove a subscription at any time
- User can have up to 100 subscriptions, no more than that
- User can also search through his/her subscriptions by using any of the following filters: list of usernames, simple substring match for the post title, simple substring match for the post text, start date published and end date published
- List of usernames should have a limit (e.g. up to 10 usernames) and should contain usernames that exist
- If the user didn't provide a start date, it implies all the posts from the beginning of time until the end date (included)
- If the user didn't provide an end date, it implies all the posts from the start date (included) until now
- User can get notified each time a new post appears from one of his/her subscriptions, should receive the subscription username, post title and post text, notification frequency should be controlled by the configuration of the backend service
- This part of the assignment is optional depending on the availability of the candidate
- If you are not able to find time to implement it, that's okay, in that case, make sure to explain (in writing) how would you build this feature and how would the APIs look like so that the Embed dev team knows what to expect once this feature is complete (pretend like in the meanwhile we will mock your APIs depending on the description you provide)
- Access to user profile, user posts and subscriptions should be protected via an authorization token
- Response time should be limited to 2 seconds for every non-search request
- Response time should be limited to 30 seconds for every search request
- In case of an error, the response should provide some kind of feedback about the error (e.g. 404 Bad Request with response body "Username does not exist")
- Should be able to sustain up to 100 daily active users
- Should be able to sustain up to 10 parallel active users
- Create unit tests for at least one part of your code e.g. public methods of one class that you have created (as a showcase, but feel free to create unit tests for anything you want if you have time)
- Add a sufficient amount of documentation in the code according to what you feel necessary in case anyone else would take over this project from you in the future
- All the user data should be persisted on local storage, which means when the backend service is restarted (e.g. after a crash) no user data is lost
- Access to the data store from the backend service should be as secure as possible
- All created data structures should be optimized to maximize the speed of required queries (triggered by the backend service)
- Should be able to sustain up to 1000 unique user profiles
- Should be able to sustain up to 100 parallel connections
Make sure to prepare some kind of development environment that works best for you. The only requirement is that the environment should be reproducible on another host so that your code can be run and tested by Embed devs.
Recommended way would be to use Docker e.g. using docker-compose you can create an environment to bundle your Python backend service with a data store such as MongoDB or PostgreSQL.
Or, more simply, just pull the Docker image for the data store you want to use (e.g. https://hub.docker.com/_/mongo) and connect to it via your Python backend service running in the Python virtual environment (e.g. https://github.com/ruanbekker/mongodb-with-python-tutorial).
If you're not familiar with Docker at all, that's okay, just use any approach you're familiar with and make sure to give instructions so we can set it up on our side.
When you finish with the assignment, please prepare the following:
- Code and other resoures uploaded on your private GitHub or Bitbucket account
- Share the link to your public git repository (from GitHub or Bitbucket) where you uploaded everything so the Embed dev team can check it out
README.mdfile with instructions on how to build, configure and run your code (the service and the data store)DOCS.mdfile (or multiple files) where you documented all of your APIs so the Embed dev team can see how to integrateTESTING.mdfile (or multiple files) where you documented how you tested the APIs with some examples (e.g. usingcurl, Postman, Swagger, Python or shell script or any other testing approach)
Intellectual property of this code is only yours, feel free to leave it on your GitHub or Bitbucket account as open source if you like and use it as a showcase for future purposes. Embed will not request the removal of the code once the assignment is complete and verified.
If you have any additional questions or require assistance, please don't hesitate to contact us via e-mail: iva@embed.xyz