YoussefMahmod/MoneyTransfering-API

MoneyTransfering-API

This is an API for transfer money between two accounts using GOLang.

1. Database Design(Used in-memory DS to mimic database)

• account table: id (int, PK), name (string), balance (decimal), created_at (timestamp), updated_at (timestamp).
• transaction table: id (int, PK), from_account_id (int, FK -> account.id), to_account_id (int, FK -> account.id), amount (decimal), created_at (timestamp).

2. Models

• Built Structs for Account and Transaction corresponding to the database tables.
• Expose Only interfaces instead of the actual structs.

3. Data Store

• Mimic models and indices using DSA(Datastructures and Algorithms).
• Built shardedMap for more concurrency performance.
• Handled concurrency (read and write locks)

4. Services

• Splited bulks into chunks and assign goroutine to increase the performance.
• Used goroutine for inserting each element in chunk(As it now sharded).
• Handled Concurrent Transfering by deadlock avoidance technique.
  • always sort IDs of both accounts to ensure consistancy behavior and locking.
  • always lock the account with minimum ID value to avoid deadlock. REF: services/account.go:111

5. APIs

• Split the API into two resources /accounts and /transactions.
• Each one handle it's own flow.
• Wrote Integration tests for all endpoints.
  • you can run it using go test -v ./api/api_tests
  • you can run the server using go run main.go
• Documented the API HERE

TODO:

• add getting transactions between two dates(Range Search) we can do that with 3 different options.
  1. AVL, Balanced BSTs.
  2. B-Trees.
  3. Interval trees.
• setting a monitoring service for the API (Performance and Error).

Sequence Diagram

Upcoming features

• Deactivate Accounts. As we could use the transactions' data history in training Ai Models to create a new AI-based features.
• Enhance data ingestion by using background jobs and queues.