Back End Developer

HappieHire
Greater Bengaluru Area

Role: Senior Backend Engineer

Location: Bangalore

Experience: 4+ years

Role Description:

We are seeking an experienced and systems-minded Backend Developer (Python / FastAPI) with 4+ years of hands-on experience to build high-performance, asynchronous APIs and scale core backend infrastructure. In this role, you will design clean, maintainable microservices, optimize data models across relational, NoSQL, and vector databases, and implement robust background processing and event-driven architectures.

Responsibilities:

  • API Architecture and Development: Design, build, and maintain enterprise-grade RESTful APIs using Python and FastAPI, applying async programming concepts, concurrency, and event-driven patterns.
  • Database Design and Vector Management: Architect, optimize, and manage schemas across SQL (e. g., PostgreSQL), NoSQL (e. g., MongoDB), and vector databases (e. g., Qdrant, Pinecone, and Pgvector) for AI/ML and enterprise workloads.
  • System Performance and Scalability: Optimize query performance, data modeling, API response times, and system concurrency for heavy traffic applications.
  • Asynchronous and Event Processing: Integrate and maintain high-throughput background processing, queuing, and caching mechanisms using Redis and Kafka.
  • Security and Clean Architecture: Enforce strict authentication/authorization workflows (OAuth2, JWT, RBAC) while maintaining modular code structure, automated test coverage, and clean software engineering principles.
  • Infrastructure Collaboration: Deploy and manage microservices in cloud environments, ensuring operational reliability and continuous deployment efficiency.

Requirements:

  • Core Language Expertise: 4+ years of dedicated professional backend experience in Python.
  • FastAPI and Async Mastery: Proven track record building asynchronous web applications with a deep understanding of asyncio, GIL nuances, event loops, concurrency, and non-blocking I/O operations.

Multi-Database Proficiency:

  • SQL: Complex queries, schema design, indexing, and performance tuning (PostgreSQL/MySQL).
  • NoSQL: Document/Key-Value stores (MongoDB, DynamoDB, etc. ).
  • Vector DBs: Practical experience with vector data modeling, indexing algorithms (HNSW, IVFFlat), and similarity searching.
  • Caching and Messaging Systems: Hands-on experience with Redis (caching, pub/sub) and Kafka (event streaming, consumer groups, topic partitioning).
  • Security and Auth: Strong grasp of secure API design, OAuth2, JWT, rate limiting, and RBAC strategies.
  • Engineering Standards: Commitment to clean architecture, SOLID principles, CI/CD pipelines, containerization (Docker), and automated testing frameworks (PyTest).

Tech Stack Summary:

  • Language and Frameworks: Python 3.10+, FastAPI, Pydantic, SQLAlchemy / Tortoise ORM.
  • Databases: PostgreSQL / MySQL, MongoDB, and Vector DBs (Pgvector, Qdrant, Pinecone, or similar).
  • Caching and Messaging: Redis, Apache Kafka, Celery.
  • DevOps and Cloud: Docker, AWS/GCP services, GitHub Actions / CI/CD.

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