Senior Backend Developer

We are seeking a seasoned Senior Python Backend Developer with a total of 8+ years of professional software engineering experience, including a minimum of 5+ years dedicated strictly to web development. In this role, you will lead the architectural design, development, and scaling of our high-performance web systems. You will leverage Fast API to build robust asynchronous APIs, utilise advanced ORM tools to design efficient data layers, and implement secure, self-documenting API standards.

Responsibilities:

• Design and develop RESTful APIs using Fast API following our established API standards and best practices.
• Implement robust data models and database interactions using SQLAlchemy and PostgreSQL.
• Optimise database queries, handle complex migrations (e. g., Alembic), and implement caching strategies.
• Implement secure authentication and authorisation mechanisms using OAuth2 and JWT (JSON Web Tokens).
• Develop and maintain core business logic in service and repository layers.
• Ensure all endpoints are fully documented and compliant with OpenAPI/Swagger specifications using FastAPI's native capabilities.
• Write comprehensive unit, integration, and end-to-end tests for all code.
• Create clear, detailed documentation for code, APIs, and architectural decisions.
• Collaborate with frontend developers to define API contracts and integration points.
• Implement and maintain high availability patterns and performance optimisations.
• Participate in code reviews, providing constructive feedback to peers.
• Troubleshoot and resolve complex technical issues across the application stack.
• Contribute to architectural decisions and help evolve our technology standards.

Requirements:

• Overall 8+ years of professional experience in backend development.
• Minimum of 5+ years of dedicated experience in web development, building production-grade web applications and APIs.
• Strong proficiency in Python (6+ yrs) with a solid understanding of type hints, async/await, and modern Python features.
• 2+ years of production experience with Fast API.
• Proficiency with relational databases, particularly PostgreSQL.
• Working knowledge of SQLAlchemy.
• Experience implementing RESTful APIs and understanding of API design principles.
• Strong understanding of software testing approaches (unit, integration, end-to-end).
• Familiarity with containerization (Docker) and container orchestration.
• Experience with Git version control and CI/CD pipelines.
• Knowledge of secure coding practices and common security vulnerabilities.
• Experience with Pydantic for data validation and schema definition.
• Familiarity with PostgreSQL advanced features (JSONB, full-text search, etc. ).
• Experience with asynchronous programming in Python.
• Experience with Uvicorn, an ASGI web server, for Python.
• Understanding of infrastructure as code (Terraform, Azure Bicep).
• Experience with Kubernetes in production environments.
• Understanding of event-driven architecture and message brokers.
• Exposure to microservices architecture patterns.
• Experience with monitoring and observability tools.
• Contributions to open-source projects.

Technical Competencies:

• Python 3.9+ features and language constructs.
• Type hints and static type checking with mypy.
• Error handling and exception management.
• Asynchronous programming with asyncio.
• Documentation using Google-style docstrings.

Web Frameworks and APIs:

• Practical experience implementing OAuth2 flows and securely managing JWT authentication.
• Expert-level production experience with FastAPI, Pydantic, and asynchronous Python programming
• Request validation and response formatting.
• Performance optimisation techniques.

Database:

• PostgreSQL schema design and optimisation.
• Deep, hands-on experience with modern Python ORMs, specifically SQLAlchemy (v2.0+)
• Query optimisation and performance tuning.
• Transaction management.
• Strong proficiency in SQL (PostgreSQL, MySQL) and database migration tools like Alembic.

Testing:

• Test-driven development practices.
• Proficiency in testing asynchronous code and secure endpoints using pytest
• Integration testing for APIs and databases.
• Mocking and fixtures.
• Code coverage analysis.

DevOps and Infrastructure (Nice to have):

• Solid knowledge of Docker, Kubernetes, and cloud ecosystems (Azure)
• CI/CD pipeline configuration.
• Infrastructure as code concepts.

Development Standards Expertise:

The ideal candidate will demonstrate an understanding of and commitment to:

• Domain-driven design principles
• API-first development approach
• Monitoring and logging implementation.
• High availability patterns
• Test-driven development
• Security by design
• Experience with Python performance profiling and memory management.
• Familiarity with database optimisation techniques (indexing, connection pooling, and query plan analysis).
• Continuous delivery practices
• Proven experience building self-documenting APIs with OpenAPI / Swagger UI.
• Code quality and maintainability
• Performance optimization
• Error handling best practices

Must-haves:

• Solid web development understanding.
• Python backend development: FastAPI preferred; Django + less FastAPI acceptable.
• At least Intermediate SQL (4 yrs) - it can be Postgres, MS SQL, Oracle - doesn't matter as long as they can write intermediate-level queries/functions / stored procedures.
• Familiar with modern software project practices: CI/CD pipelines, Git, Cloud.
• Able to review code and guide/mentor the team on architecture standards and guidelines.
• A quick learner who can scale up and fill gaps where the team needs coverage.
• Communication good enough to understand US accents and talk to clients.