Description

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

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

Qualifications





Required Skills (Mandatory)

- FastAPI

4+ years of deep, hands-on production experience — routing, dependency injection, async endpoints, middleware, background tasks

- Pydantic

Robust 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)

📌 Backend API Engineer (Hyderabad)
🏢 Zensar Technologies
📍 Hyderabad