151 to 175 of 191 FastAPI Jobs in the City of London

Sells: Work on cutting-edge AI systems that power healthcare innovation at scale. Full remote flexibility across the UK, total ownership of greenfield projects, modern tech stack (Python/FastAPI/Cloud), and a culture that rewards curiosity, autonomy, and clean engineering. An AI HealthTech company is expanding its high-calibre engineering team and looking for Software Engineers who thrive … engineering role where you'll be designing, building, and scaling complex systems that solve real problems in healthcare. Role Design and build production-grade backend systems using Python and FastAPI Develop distributed, high-performance services and APIs for AI-driven platforms Contribute to architecture decisions, scalability planning, and system optimisation Implement best practices in testing, CI/CD, and performance … end-to-end solutions Drive continuous improvement and innovation across the engineering organisation Skills 5+ years of experience as a Software Engineer building modern backend systems Strong Python skills (FastAPI preferred; Flask or Django also considered) Knowledge of system design, data modelling, and distributed architecture Familiarity with cloud technologies (AWS, Azure, or GCP) and containerisation Understanding of software engineering best More ❯

occasional Visits Start Date: Immediate (Only considering for who can start by next week) No. of Positions: 1 Job Description: Python Developer Principal Accountabilities Develop backend systems using Python, FastAPI, and related frameworks Manage data with SQL Alchemy, working across PostgreSQL, CosmosDB, and Redis Build scalable cloud solutions using Azure PaaS services (App Services, Function Apps, API Management, etc.) Design … onboarding Collaborate with cross-functional teams to align on technical goals Foster a culture of innovation and continuous improvement Technical Skills Python Expertise: Strong proficiency in Python, especially with FastAPI, SQL Alchemy, and Celery. Azure PaaS: Hands-on experience with Azure services like App Services, Function Apps, API Management, Service Bus, Storage, Key Vaults, Azure SQL, and Cosmos DB. API More ❯

occasional Visits Start Date: Immediate (Only considering for who can start by next week) No. of Positions: 1 Job Description: Python Developer Principal Accountabilities Develop backend systems using Python, FastAPI, and related frameworks Manage data with SQL Alchemy, working across PostgreSQL, CosmosDB, and Redis Build scalable cloud solutions using Azure PaaS services (App Services, Function Apps, API Management, etc.) Design … onboarding Collaborate with cross-functional teams to align on technical goals Foster a culture of innovation and continuous improvement Technical Skills Python Expertise: Strong proficiency in Python, especially with FastAPI, SQL Alchemy, and Celery. Azure PaaS: Hands-on experience with Azure services like App Services, Function Apps, API Management, Service Bus, Storage, Key Vaults, Azure SQL, and Cosmos DB. API More ❯

Explore the forefront of financial technology with a leader in AI-driven automation software. You’ll join a team dedicated to pushing the boundaries of what’s possible in the trading world, using innovation to drive real results. Python AI More ❯

Explore the forefront of financial technology with a leader in AI-driven automation software. You’ll join a team dedicated to pushing the boundaries of what’s possible in the trading world, using innovation to drive real results. Python AI More ❯

s and high-frequency event streams, as well as making improvements to their current platform. Senior Python Developer - Python, SQL, Databricks, AWS/Azure Key skills and experience: Python FastAPI SQL Databricks AWS/Azure API's Hybrid working with 3-days a week required in a Central London office Pays up to £90k + benefits To be considered, you More ❯

Backend Engineer (Python) - Tech for Good | £75m-Funded Startup Location: London, UK - 1 day in office minimum Salary: £60k-£70k + benefits Tech Stack: Python, FastAPI, Docker, AWS, Django, PySpark, PyTorch, Kubernetes About the Company Our client is an ambitious tech-for-good organisation on a mission to reduce carbon emissions across the UK using AI-driven technology. With more … cloud scalability. Mentor junior engineers and share best practices within the team. About You 3–5 years of backend engineering experience. Strong proficiency with Python and frameworks such as FastAPI or Django. Experience developing and scaling RESTful APIs and backend systems. Solid understanding of cloud infrastructure (AWS preferred). Familiarity with containerization (Docker, Kubernetes). Exposure to PySpark or PyTorch More ❯

Backend Engineer (Python) - Tech for Good | £75m-Funded Startup Location: London, UK - 1 day in office minimum Salary: £60k-£70k + benefits Tech Stack: Python, FastAPI, Docker, AWS, Django, PySpark, PyTorch, Kubernetes About the Company Our client is an ambitious tech-for-good organisation on a mission to reduce carbon emissions across the UK using AI-driven technology. With more … cloud scalability. Mentor junior engineers and share best practices within the team. About You 3–5 years of backend engineering experience. Strong proficiency with Python and frameworks such as FastAPI or Django. Experience developing and scaling RESTful APIs and backend systems. Solid understanding of cloud infrastructure (AWS preferred). Familiarity with containerization (Docker, Kubernetes). Exposure to PySpark or PyTorch More ❯

team, contributing to the development of cutting-edge applications that accelerate drug discovery and enable personalised therapies. The ideal candidate will have strong Python backend development experience, preferably with FastAPI, and be proficient in cloud-native infrastructure (Google Cloud preferred), DevOps practices, and automated testing. While a background in life sciences is a plus, a passion for improving healthcare through … engineers in the team and across allied teams, to build an end-to-end pipeline consuming other data products Basic qualifications: Demonstrated experience of Python backend development (e.g. using FastAPI) Cloud experience (e.g. Google Cloud and cloud run preferred) including core web application infrastructure is essential Unit testing experience (e.g. pytest) Experience within Life Sceiences or Pharma Sector Strong knowledge More ❯

team, contributing to the development of cutting-edge applications that accelerate drug discovery and enable personalised therapies. The ideal candidate will have strong Python backend development experience, preferably with FastAPI, and be proficient in cloud-native infrastructure (Google Cloud preferred), DevOps practices, and automated testing. While a background in life sciences is a plus, a passion for improving healthcare through … engineers in the team and across allied teams, to build an end-to-end pipeline consuming other data products Basic qualifications: Demonstrated experience of Python backend development (e.g. using FastAPI) Cloud experience (e.g. Google Cloud and cloud run preferred) including core web application infrastructure is essential Unit testing experience (e.g. pytest) Experience within Life Sceiences or Pharma Sector Strong knowledge More ❯

Software Engineer – Python/FastAPI/React/Functional programming/Typescript Location: London, UK (Hybrid) Type: Full-time Level: Mid to Senior Salary: £70,000 to £100,000 About the Role: This startup is building a cutting-edge platform to transform how engineers design physical products. Instead of creating one solution at a time, this system enables users to … about real-world engineering not just building software, but helping change how things are designed and built. Opportunities: Frontend or Backend Tech Stack within the engineering environment: Backend: Python, FastAPI, Pydantic, PostgreSQL, Docker Frontend: React, TypeScript, Vite Infrastructure: GitHub Actions, GCP, Kubernetes (optional) Paradigms: Functional programming, async APIs, event-driven architecture Responsibilities Build and maintain backend services using FastAPI and … in Computer Science, Engineering, Physics, Mathematics, or a related technical field 2+ years of experience building web applications in a production environment Strong experience with Python and API frameworks (FastAPI, Flask, etc.) Proficiency with React and TypeScript Comfort or interest in functional programming principles and clean code architecture A genuine interest in engineering and the physical world Ability to thrive More ❯

Software Engineer – Python/FastAPI/React/Functional programming/Typescript Location: London, UK (Hybrid) Type: Full-time Level: Mid to Senior Salary: £70,000 to £100,000 About the Role: This startup is building a cutting-edge platform to transform how engineers design physical products. Instead of creating one solution at a time, this system enables users to … about real-world engineering not just building software, but helping change how things are designed and built. Opportunities: Frontend or Backend Tech Stack within the engineering environment: Backend: Python, FastAPI, Pydantic, PostgreSQL, Docker Frontend: React, TypeScript, Vite Infrastructure: GitHub Actions, GCP, Kubernetes (optional) Paradigms: Functional programming, async APIs, event-driven architecture Responsibilities Build and maintain backend services using FastAPI and … in Computer Science, Engineering, Physics, Mathematics, or a related technical field 2+ years of experience building web applications in a production environment Strong experience with Python and API frameworks (FastAPI, Flask, etc.) Proficiency with React and TypeScript Comfort or interest in functional programming principles and clean code architecture A genuine interest in engineering and the physical world Ability to thrive More ❯

Backend Engineer, you’ll play a pivotal role in designing, building, and scaling the company’s backend systems and infrastructure. You’ll architect reliable, high-performance services in Python (FastAPI, Flask) and help evolve the platform for large-scale AI workloads. A strong DevOps mindset and experience with production-scale systems will be key to success. Key Responsibilities: Architect and … develop scalable, high-performance backend services using Python (FastAPI, Flask) and Node.js. Design, build, and maintain an AWS-based platform supporting AI, data, and web products. Manage and optimise Kubernetes clusters for availability, performance, and cost efficiency. Develop and maintain CI/CD pipelines with GitHub Actions for automated testing and deployment. Optimise systems for performance, reliability, and scalability in More ❯

As a Senior Backend Engineer, youll play a pivotal role in designing, building, and scaling the companys backend systems and infrastructure. Youll architect reliable, high-performance services in Python (FastAPI, Flask) and help evolve the platform for large-scale AI workloads. A strong DevOps mindset and experience with production-scale systems will be key to success. Key Responsibilities: Architect and … develop scalable, high-performance backend services using Python (FastAPI, Flask) and Node.js. Design, build, and maintain an AWS-based platform supporting AI, data, and web products. Manage and optimise Kubernetes clusters for availability, performance, and cost efficiency. Develop and maintain CI/CD pipelines with GitHub Actions for automated testing and deployment. Optimise systems for performance, reliability, and scalability in More ❯

vector DB integration, eval hooks, cost/safety guardrails). Essential Requirements 3-6+ years building production backends/services , with shipped work and clear ownership. Strong Python (FastAPI) and database skills ( PostgreSQL/MongoDB ); solid API design fundamentals. Familiarity with AWS serverless patterns and Docker for bespoke services; basic CI/CD concepts. Comfortable with Redis (caching/… orchestration; MCP servers for integrations. Security hygiene (secrets, permissions, least-privilege) and practical data-privacy basics. Planning & execution in Linear (or similar). Tools & Stack Backend/Runtime: Python (FastAPI), Node.js. Datastores: PostgreSQL, MongoDB (as appropriate), Redis (caching/sessions). Vectors/Embeddings: Chroma (or similar). AI Models & APIs: Claude (Anthropic), Gemini (Google); Amazon Nova Canvas (vision), Deepgram More ❯

vector DB integration, eval hooks, cost/safety guardrails). Essential Requirements 3-6+ years building production backends/services , with shipped work and clear ownership. Strong Python (FastAPI) and database skills ( PostgreSQL/MongoDB ); solid API design fundamentals. Familiarity with AWS serverless patterns and Docker for bespoke services; basic CI/CD concepts. Comfortable with Redis (caching/… orchestration; MCP servers for integrations. Security hygiene (secrets, permissions, least-privilege) and practical data-privacy basics. Planning & execution in Linear (or similar). Tools & Stack Backend/Runtime: Python (FastAPI), Node.js. Datastores: PostgreSQL, MongoDB (as appropriate), Redis (caching/sessions). Vectors/Embeddings: Chroma (or similar). AI Models & APIs: Claude (Anthropic), Gemini (Google); Amazon Nova Canvas (vision), Deepgram More ❯

Full-Stack Engineer – London (Hybrid) Our client is a fast-growing software business delivering market-leading ticketing products to forward-thinking organisations worldwide. Their platform is used by hundreds of thousands of people and powers ticket sales for some of More ❯

Full-Stack Engineer London (Hybrid) Our client is a fast-growing software business delivering market-leading ticketing products to forward-thinking organisations worldwide. Their platform is used by hundreds of thousands of people and powers ticket sales for some of More ❯

maintain end-to-end product features used by enterprise customers. Develop modern, responsive interfaces using React/Next.js . Design and optimize APIs, data pipelines, and integrations using Python (FastAPI/Django) . Collaborate with design, product, and AI teams to deliver new functionality quickly and reliably. Contribute to architectural decisions, system scalability, and engineering best practices. What We’re … Looking For: Proven experience as a Full-Stack Engineer in a startup or fast-paced environment. Strong proficiency in React/Next.js and Python (FastAPI/Django) . Experience shipping scalable, production-grade software. Exposure to or interest in AI/ML-driven products . Startup experience or comfort with high ownership and autonomy is a massive plus . Package More ❯

maintain end-to-end product features used by enterprise customers. Develop modern, responsive interfaces using React/Next.js . Design and optimize APIs, data pipelines, and integrations using Python (FastAPI/Django) . Collaborate with design, product, and AI teams to deliver new functionality quickly and reliably. Contribute to architectural decisions, system scalability, and engineering best practices. What We’re … Looking For: Proven experience as a Full-Stack Engineer in a startup or fast-paced environment. Strong proficiency in React/Next.js and Python (FastAPI/Django) . Experience shipping scalable, production-grade software. Exposure to or interest in AI/ML-driven products . Startup experience or comfort with high ownership and autonomy is a massive plus . Package More ❯

Senior Data Engineer (Python, FastAPI, GCP) | Permanent | London (1 day a week on-site) 🚀 Series C Scale-up | $50m raise in 2025 My client are a fast-scaling SaaS scale-up (Series C, $50m raised in 2025) that is redefining how global powerhouses operate. Their AI-enabled platform supports over 1,000+ brands worldwide, streamlining business processes like never seen … scope to grow into leadership as the data team scales. ✨ Remote-first culture – flexibility to work from anywhere What you’ll be doing: API strategy & development – own and scale FastAPI endpoints that deliver real-time access to platform data. Data pipeline development – build ingestion and replication pipelines with best-in-class observability, latency, and resilience. Platform technical vision – influence architecture … reliability and trustworthiness. Collaboration – partner with engineers, product managers, and commercial teams to deliver production-grade solutions. Tech stack and requirements: Python – must-have, with production-grade engineering expertise FastAPI – must-have, proven experience building APIs in production Google Cloud Platform (GCP) – must-have, ie BigQuery, Cloud Run, and Cloud Storage dbt – strong advantage, with scope to shape best practice More ❯

Senior Data Engineer (Python, FastAPI, GCP) | Permanent | London (1 day a week on-site) Series C Scale-up | $50m raise in 2025 My client are a fast-scaling SaaS scale-up (Series C, $50m raised in 2025) that is redefining how global powerhouses operate. Their AI-enabled platform supports over 1,000+ brands worldwide, streamlining business processes like never seen … Clear scope to grow into leadership as the data team scales. Remote-first culture flexibility to work from anywhere What youll be doing: API strategy & development own and scale FastAPI endpoints that deliver real-time access to platform data. Data pipeline development build ingestion and replication pipelines with best-in-class observability, latency, and resilience. Platform technical vision influence architecture … reliability and trustworthiness. Collaboration partner with engineers, product managers, and commercial teams to deliver production-grade solutions. Tech stack and requirements: Python must-have, with production-grade engineering expertise FastAPI must-have, proven experience building APIs in production Google Cloud Platform (GCP) must-have, ie BigQuery, Cloud Run, and Cloud Storage dbt strong advantage, with scope to shape best practice More ❯

Technical Lead – Lead Tech Strategy for a Profitable FinTech Scale-Up Hybrid (London) or remote within the UK £160,000 per annum plus stock options Python | Django | FastAPI | AWS | Rust | Postgres | Event-Driven Architecture | Machine Learning Technical Lead - We're working with a leading fintech scale-up that’s transforming how small businesses access finance. Backed by a strong track … a chat. Technical Lead – Lead Tech Strategy for a Profitable FinTech Scale-Up Hybrid (London) or remote within the UK £160,000 per annum plus stock options Python | Django | FastAPI | AWS | Rust | Postgres | Event-Driven Architecture | Machine Learning More ❯

Technical Lead Lead Tech Strategy for a Profitable FinTech Scale-Up Hybrid (London) or remote within the UK 160,000 per annum plus stock options Python | Django | FastAPI | AWS | Rust | Postgres | Event-Driven Architecture | Machine Learning Technical Lead - We're working with a leading fintech scale-up thats transforming how small businesses access finance. Backed by a strong track record … a chat. Technical Lead Lead Tech Strategy for a Profitable FinTech Scale-Up Hybrid (London) or remote within the UK 160,000 per annum plus stock options Python | Django | FastAPI | AWS | Rust | Postgres | Event-Driven Architecture | Machine Learning More ❯

. 5–10 years’ software engineering experience with a proven track record of shipping production systems (not just managing teams). Deep experience in backend development, ideally with Python, FastAPI, SQLAlchemy, and PostgreSQL . A genuine interest in AI — you’ve built or integrated AI/LLM-driven tools, experimented with AI frameworks, or used AI-assisted coding tools. Curiosity … experience mentoring or leading small teams is ideal but not essential; this is a role for a builder first, leader second . Tech Snapshot Languages: Python 3.11+, TypeScript Frameworks: FastAPI, SQLAlchemy, Alembic Infrastructure: AWS (IAM, SES, Bedrock) Architecture: Event-driven, API-first, AI-integrated pipelines Databases: PostgreSQL Why This Role Step up from Senior Engineer to Lead Engineer in a More ❯