Senior Backend Engineer | Python, FastAPI & AI/LLM Systems

Python & FastAPI Backend Development

Extensive experience building production-grade Python services using FastAPI, including multi-tenant architectures, rule-driven domain logic, authentication, RBAC, and audit-friendly API surfaces. Ownership of features end to end from API design and data modelling through profiling, testing, and release.

AI & LLM Systems (RAG, LangChain, Vector Search)

Hands-on expertise in building and deploying RAG pipelines using LangChain and ChromaDB, including ingestion pipeline design, semantic search with embeddings and cosine similarity, tool-calling and agentic workflows, prompt design, and OCR ingestion pipelines for production environments.

PostgreSQL & Database Optimisation

Deep knowledge of PostgreSQL and MongoDB schema design, query tuning, indexing, N+1 elimination, and data modelling. Application of strict optimisation standards across latency-critical routes and async I/O paths in live production workloads.

Cloud & DevOps (AWS, Docker, CI/CD)

Practical experience configuring and operating AWS-hosted environments, building containerised setups with Docker and Docker Compose, and creating end-to-end CI/CD pipelines with GitHub Actions and infrastructure-as-code tooling.

REST API Design & Async Architecture

Solid background in REST API design principles, asyncio-based background workers, event-driven services, and multi-tenant platform architecture. Experience refactoring hot paths and background workers to reduce latency and resource usage.

Frontend Development (React, Next.js, RemixJS, AngularJS)

Delivery of SSR frontends using Next.js, RemixJS, and Tailwind CSS, as well as reusable React components and AngularJS interfaces on shared SCSS design systems for complex business workflows.

Testing & Quality Assurance (pytest)

Application of unit and integration testing with pytest across services, maintaining coverage and verifying business rule isolation from transport and persistence concerns. Experience with performance profiling and optimisation.

Node.js & Express Backend Services

Extension of Express and Node.js APIs with new endpoints, middleware, and integration points against existing production data models, replacing brittle legacy logic with modular, testable service layers.

Domain-Driven Design & Clean Architecture

Application of domain-driven design, clean architecture principles, and modular service layering to build maintainable, scalable systems. Experience with Agile and Scrum delivery in distributed, English-speaking teams.