Backend Engineer at TruePeer

Role Overview

Backend Engineer at TruePeer, a fintech/crypto platform, where I designed and implemented scalable microservices for financial operations.

Key Responsibilities & Achievements

Microservices Architecture

• Designed and implemented domain-driven microservices in Golang for a fintech/crypto platform following clean architecture patterns where handlers validate input from routes and delegate to services
• Services orchestrate business logic, execute type-safe SQLc queries, map to DTOs, and manage error handling with structured logging
• Built and maintained REST API endpoints covering wallet operations, P2P payments, and KYC flows
• Processing 10k–20k+ daily transactions across core financial service domains using double-entry accounting principles

Security & Authentication

• Implemented JWT-based stateless authentication with token refresh rotation, session invalidation, and RBAC on all financial API routes
• Added per-route token-bucket rate limiting, reducing abuse attempts by ~40%
• Input validation, CORS enforcement, and structured audit logging on sensitive operations such as withdrawals and KYC submissions

Database & Data Management

• Used PostgreSQL as the primary datastore with SQLc for type-safe query generation and Goose for versioned schema migrations
• Applied ACID transactions across financial operations (wallet balance updates, payment recording, audit log writes) to prevent race conditions
• Ensured data consistency under concurrent load

Observability & Performance

• Instrumented API routes with Prometheus metrics and Grafana dashboards tracking P95 latency and error rates
• Reduced average incident detection time by around 30%
• Used Redis for caching and lightweight event propagation between services

DevOps & Testing

• Containerized services with Docker and contributed to GitHub Actions CI/CD pipelines
• Pipelines covering unit tests, integration tests, linting, and staged deployments to Kubernetes
• Maintained ~70% test coverage across API handlers and service logic following TDD practices

Tech Stack

Languages: Golang
Databases: PostgreSQL, Redis
Tools: SQLc, Goose, Docker, Kubernetes
Observability: Prometheus, Grafana
CI/CD: GitHub Actions