Backend API Engineer

About the Role We're looking for a senior Backend API Engineer with 8+ years of experience building and scaling production APIs, including at least 4 years working hands-on with FastAPI. You will design, build, and maintain high-performance, secure backend services, and act as a technical leader on architecture and system design decisions.

Experience Requirements

• 8+ years of overall experience building and operating backend APIs in production environments
• Minimum 4 years of hands-on experience with FastAPI specifically (not just general Python API frameworks)
• Demonstrated experience owning services end-to-end — design, development, deployment, and monitoring
• Prior experience mentoring engineers or leading technical design discussions is a plus

Required Skills (Mandatory)

• FastAPI 4+ years of deep, hands-on production experience — routing, dependency injection, async endpoints, middleware, background tasks
• Pydantic Strong command of data validation, serialization, custom validators, and schema design (v1/v2)
• Redis Caching strategies, pub/sub, session/token storage, expiry and eviction policies

Core Skills (Working Knowledge Expected)

• System Design — ability to architect scalable, fault-tolerant, high-throughput backend systems
• Authentication & Authorization — OAuth2, RBAC, secure API access patterns
• JWT — token issuance, validation, refresh flows, and security best practices
• HTTPX — async HTTP client usage for reliable service-to-service communication
• API Design — RESTful principles, versioning, rate limiting, backward compatibility
• Message Queues — experience with Kafka, RabbitMQ, SQS, or Celery for async processing
• L1 Cache Handling — in-memory/application-level caching alongside Redis (L2) for low-latency reads
• Exception Handling (RFC 9457) — standardized "Problem Details for HTTP APIs" error responses
• SQL — strong working knowledge of relational databases (PostgreSQL/MySQL), query optimization, and ORM usage (SQLAlchemy)

Responsibilities

• Design and develop high-performance RESTful APIs using FastAPI with clean, validated schemas via Pydantic
• Architect scalable backend systems, making sound trade-offs on performance, reliability, and maintainability
• Implement multi-layer caching (Redis + in-memory L1 cache) to optimize latency and throughput
• Build secure authentication/authorization flows using JWT and OAuth2
• Integrate with external and internal services using async HTTP clients (HTTPX)
• Design and consume message queues for asynchronous and event-driven processing
• Implement standardized, consistent error handling following RFC 9457
• Write efficient, optimized SQL queries and review database interaction patterns
• Drive system design discussions and review architecture proposals across teams
• Write unit/integration tests and uphold high code quality and observability standards

Nice to Have

• Experience with Docker, Kubernetes, and CI/CD pipelines
• Familiarity with observability tools (logging, tracing, metrics)
• Exposure to microservices architecture at scale