Backend & infra, 2025
NexusBank
A banking API with hashed PINs, validated transfers and rule-based fraud scoring.
- Role
- Personal project
- Type
- Backend & infra
- Links
- Source on GitHub
- weighted fraud risk score
- 0–100
- fraud rules
- 4
- hashed PIN auth
- bcrypt
The problem
A banking simulation is a good excuse to get the boring, important parts right: authentication, balance checks and spotting suspicious activity.
How I approached it
- 1
Secure the basics
bcrypt-hashed PIN authentication with MongoDB-backed sessions, balance-validated transfers and beneficiaries.
- 2
Score risk
Rule-based fraud detection on amount, velocity, odd hours and daily limits, combined into a weighted 0–100 risk score.
- 3
Query efficiently
Compound-indexed, paginated transaction history and aggregation-pipeline spending analytics.
What I built
- An Express 5 API with a dark-mode dashboard showing live balance updates.
The result
Every transfer is validated and scored before it lands.
Built with
- Node.js
- Express
- MongoDB
- Mongoose
- bcrypt