Senior Python Developer (FastAPI)

About us: Talent has no borders. Proxify's mission is to connect top developers around the world with opportunities they deserve. So, it doesn't matter where you are; we are here to help you fast-track your independent career in the right direction. 🙂 Since our launch, Proxify's developers have successfully worked with 1200+ happy clients to build their products and growth features. 5000+ talented developers trust Proxify and its network to fulfill their dreams and objectives. Proxify is shaped by a global network of supportive, talented developers interested in remote full-time jobs. Our Glassdoor (4.5/5) and Trustpilot (4.8/5) ratings reflect the trust developers place in us and our commitment to our members' success. The Role: We are looking for a Senior Python Developer specializing in FastAPI on behalf of one of our high-growth clients to architect, build, and scale their core cloud-native backend services. In this role, you will take ownership of developing high-throughput, low-latency asynchronous APIs that power data-intensive platform features.You are a perfect candidate if you are growth-oriented, you love what you do, and you enjoy working on new ideas to develop exciting products. What we’re looking for: - 3+ years of dedicated, hands-on production experience building high-performance asynchronous web services with FastAPI and modern Python (3.10+). Deep mastery of Python's asyncio ecosystem, dependency injection, and Pydantic v2 data validation. -  5+ years of total software engineering experience designing, deploying, and maintaining production-grade distributed systems and RESTful APIs. - Solid proficiency with relational databases (PostgreSQL), writing optimized raw SQL or leveraging ORMs like SQLAlchemy and Alembic for schema migrations and query tuning. Caching layer experience with Redis is essential. - Practical experience building decoupled services using message queues and event streaming platforms (e.g., RabbitMQ, Celery, or Apache Kafka). - Strong daily proficiency with Docker, Kubernetes or AWS container services (ECS/EKS), and setting up CI/CD deployment pipelines (GitHub Actions, GitLab CI). - Strict adherence to software design patterns, clean code principles, and comprehensive automated testing using pytest. - Located in the CET timezone (+/- 3 hours), we are unable to consider applications from candidates in other time zones. Nice-to-Have - Experience with GraphQL or WebSocket integrations alongside standard REST protocols. - Familiarity with vector databases (Pinecone, Milvus, Qdrant) or AI/LLM orchestration frameworks (LangChain, LlamaIndex) for AI-integrated backends. - Experience migrating legacy Django or Flask monolithic architectures to decoupled FastAPI microservices. Responsibilities: - Design, build, and document secure, high-concurrency microservices and RESTful endpoints using FastAPI and OpenAPI/Swagger standards. - Profile asynchronous bottlenecks, manage event loops, optimize database queries, and scale caching layers to maintain sub-millisecond response times under peak load. - Build robust communication channels between internal services and external partner APIs using webhooks, message brokers, and background workers (e.g., Celery). - Lead technical design discussions, establish testing benchmarks, and conduct thorough peer code reviews to ensure system reliability and security compliance. - Collaborate closely with DevOps teams to containerize applications, monitor cloud health metrics, and streamline automated release cycles. What we offer: Get paid, not played No more unreliable clients. Enjoy on-time monthly payments with flexible withdrawal options. Predictable project hours Enjoy a harmonious work-life balance with consistent 8-hour working days with clients. Flex days, so you can recharge Enjoy up to 24 flex days off per year without losing pay, for full-time positions found through Proxify. Career-accelerati