IP Activities Assignment

This is a take-home assignment for evaluating senior Ruby on Rails developers. The assignment focuses on IP activities functionality.

Background

The application tracks IP activities for users and their trading accounts. Each IP activity has an activity type (trade, login, kyc) and is associated with either a user or a trading account.

The database contains 100M records, so performance optimization is crucial.

Assignment

Task 1: Optimize IpActivity Scopes and Implement Smart Limiting

Context:

• User has related TradingAccount model
• Both have related IpActivity model that logs user activity
• Each IpActivity has its own type:
  • kyc - IP addresses from which user passes verification, no more than 10 records
  • login - IP addresses from which user logs in, these activities are tied to user, no more than 1000 records
  • trade - activities that log IP addresses of client trading operations from different platforms, can be 1000-10000 records

Task: Display in the index controller action for further serialization and map rendering the latest user activity by date. Regardless of date, ensure that kyc and login types are always displayed (no more than 1000 per each type) and the remaining slots up to a total limit of 3000 are filled with trade activities.

Example: If a client has IP activities with types: kyc - 1, login - 500, trade - 2000 Should output: 1 + 500 + 1000 = 1501 IpActivity records

Requirements:

1. Optimize the existing scopes in the IpActivity model
2. Implement smart limiting logic that prioritizes kyc and login activities
3. Fill remaining slots with trade activities up to total limit of 3000
4. Consider database performance with 100M records
5. Maintain existing API functionality

Current scopes to optimize:

  scope :for_user, lambda { |user|
    where(user:).includes(:user, :trading_account, :ip_address_record)
                .or(where(trading_account_login: user.trading_accounts.select(:login)))
  }
  scope :recent_n_per_activity_type, lambda { |limit|
    query = <<-SQL.squish
      SELECT activity_limited.id
      FROM (SELECT DISTINCT activity_type FROM ip_activities) activity_groups
      JOIN LATERAL (
        SELECT * FROM ip_activities activity_all
        WHERE activity_all.activity_type = activity_groups.activity_type
        ORDER BY activity_all.created_at DESC
        LIMIT :limit
      ) activity_limited ON true
    SQL

    where("ip_activities.id IN (#{ApplicationRecord.sanitize_sql([query, { limit: }])})")
  }

Task 2: Design Reusable Filter Component Architecture

Context: The current implementation lacks a filtering component. The task is to design the architecture of a reusable filter component that can accept parameters, save them to the database, and be universal enough to be applied to filtering users, trading_accounts, or other models with their own parameter sets.

Requirements:

1. Design a universal filter model that can be applied to different entities (users, trading_accounts, ip_activities)
2. Filter should work in both index and filter_metadata endpoints
3. Parameters should be persistable in the database
4. Component should be reusable across different controllers and models
5. Support different filter types (date ranges, enums, text search, etc.)

Deliverables: Choose one of the implementation options:

• Option A: Complete code implementation with all necessary models, controllers, and services
• Option B: Detailed architecture description with schema design, usage examples, and implementation sketches

Consider:

• How to handle different parameter types for different models
• Database schema design for storing filter configurations
• API design for filter endpoints
• Performance implications
• Code reusability and maintainability

Getting Started

1. Clone the repository
2. Run bundle install
3. Set up the database: rails db:create db:migrate db:seed
4. Start the server: rails s

API Endpoints

• GET /api/users/:user_id/ip_activities - Returns IP activities for a user
• GET /api/users/:user_id/ip_activities/filter_metadata - Returns metadata for filtering IP activities

Testing

Run the tests with:

bin/rspec

Submission

Please provide your optimized solution along with an explanation of your approach and any trade-offs you made.