Backend Engineer (Python,Fast API)_Mumbai

Role: Backend Engineer (Python,Fast API) Location: Mumbai / Pune Experience Range: 5 – 10 Yrs Role Summary The Backend Engineer is responsible for designing, building, and maintaining production-grade backend microservices using Python and FastAPI, with a strong focus on scalability, reliability, performance, and observability. The role combines strong backend engineering fundamentals with hands-on experience in data modelling, ORM-based persistence, GenAI integration, and agentic application development using LangChain and LangGraph. Key Responsibilities Backend Microservices Development Design, build, and maintain backend microservices using Python and FastAPI Develop clean, modular, and maintainable APIs aligned with product and platform requirements Implement RESTful API endpoints, request validation, service-layer logic, and integration patterns Collaborate with frontend, data, AI, and platform teams to deliver end-to-end backend capabilities Scalability, Reliability, Performance & Observability Engineer microservices to be scalable, reliable, performant, secure, and easy to operate in production Implement logging, metrics, tracing, health checks, and alerting hooks to improve service observability Identify and resolve performance bottlenecks across API, database, and integration layers Follow engineering best practices for error handling, retries, idempotency, fault tolerance, and operational resilience Data Modelling & Persistence Design data models for microservices, including domain entities, relationships, constraints, and lifecycle states Use SQLAlchemy or similar ORM frameworks to implement database access patterns and persistence logic Create efficient schemas, indexes, queries, and migration strategies for relational databases Ensure data consistency, transactional integrity, and maintainability of service-owned data models GenAI & Agentic Application Development Design and build AI agents and agentic workflows using LangChain and LangGraph Implement tool calling, state management, workflow orchestration, memory patterns, and human-in-the-loop flows where required Integrate LLMs, prompts, retrieval components, APIs, and backend services into reliable GenAI capabilities Apply prompt engineering techniques to improve accuracy, consistency, safety, and usability of AI-powered features Required Skills & Qualifications Strong proficiency in Python and backend application development Hands-on experience building APIs and backend services using FastAPI Strong working knowledge of SQLAlchemy and ORM frameworks Experience with relational databases, SQL, schema design, indexing, and query optimization Hands-on experience with LangChain and LangGraph for building agents, tools, workflows, and LLM-powered applications Understanding of GenAI concepts, LLM integration patterns, RAG, prompt engineering, and agent orchestration Strong systems thinking across scalability, performance, reliability, observability, and maintainability