26 to 42 of 42 API Design Jobs in London

Senior Node/AWS Developer

Hiring Organisation
Method Resourcing
Location
Westminster, Greater London, UK
impact The skills and experience my client are looking for: 5+ years of experience in software engineering, with expertise in Node.js and REST API design. Strong knowledge of AWS and serverless architecture. Strong experience with TypeScript, ensuring clean, efficient, and maintainable code. Experience with CI/CD pipelines using ...

AI Platform Engineer

Hiring Organisation
The Portfolio Group
Location
London, Castle Baynard, United Kingdom
Employment Type
Permanent
owning the cloud-native platform that underpins conversational AI and generative AI products at scale. Sitting at the core of AI delivery, you will design, build, and operate the runtime, infrastructure, and operational layers supporting RAG pipelines, LLM orchestration, vector search, and evaluation workflows across AWS and Databricks. Working … platform powering conversational assistants and generative AI products. Build, operate, and optimise RAG and LLM-backed services, improving latency, reliability, and cost. Design and run cloud-native AI services across AWS and Databricks, including ingestion and embedding pipelines. Scale and operate vector search infrastructure (Weaviate, OpenSearch, Algolia, AWS Bedrock ...

Product Engineer

Hiring Organisation
Affinity Labs
Location
City of London, London, United Kingdom
full-stack product delivery, from infrastructure and AI integrations through to React/React Native interfaces, collaborating closely with founders, creators, product, and design to turn lean specs into scalable, user-loved software. We’re looking for a strong generalist with backend depth and real mobile experience. Responsibilities Implement … mobile + web frontend → APIs → data models → integrations) while maintaining quality and velocity. Build React Native mobile apps and shared component systems across products. Design and ship scalable backend services (APIs, integrations, AI workflows). Run tight build → test → iterate → ship loops; provide realistic estimates and surface blockers early. ...

Senior Java Engineer – Reactive (Spring WebFlux)

Hiring Organisation
Fynity
Location
London Area, United Kingdom
senior individual-contributor role within a high-performing engineering team, building asynchronous, message-driven systems designed for scale, resilience, and near-zero downtime. Design and implement high-throughput, low-latency systems processing millions of real-time payment events Build event-driven architectures using modern Java and reactive frameworks Work … extensively with non-blocking I/O, asynchronous flows, back-pressure, and concurrency Contribute to system and API design, focusing on scalability, fault tolerance, and observability Collaborate closely with architects, engineers, and client teams across Europe Operate in Agile environments (Scrum/Kanban) with a strong engineering culture ...

Ruby on Rails Engineer

Hiring Organisation
Rise Technical Recruitment
Location
London, United Kingdom
Employment Type
Permanent
Salary
£60000 - £80000/annum Private Healthcare + Holiday + Pensi
evolution of core Ruby on Rails operational platforms. Optimise PostgreSQL performance and Sidekiq background job efficiency. Manage secure third-party integrations and RESTful API design. Partner with Platform teams on AWS and CI/CD reliability. The Person: Deep experience with Ruby on Rails and OOP. Expert in PostgreSQL ...

Lead Full Stack Developer

Hiring Organisation
G.R.E. Recruitment Limited
Location
City of London, London, United Kingdom
Employment Type
Permanent, Work From Home
Salary
£95,000
Start Up - Smart Living Platform Fully Remote - Must be UK based £85,000 - £95,000 + Stock Options (DOE) Essential Exp: Laravel, Flutter, SaaS, API Design, MySQL/PostgreSQL/MariaDB G.R.E. Recruitment is DELIGHTED and EXCITED to partner with an exciting UK based PropTech Start-Up company … defining technical standards, scalability strategy, and product direction across the technical ecosystem. In this role you will: Own and evolve a Laravel-based REST API Develop and maintain a Flutter mobile application (iOS & Android) Design and implement secure, multi-tenant architecture Establish clean coding standards and engineering best ...

Senior Software Engineer

Hiring Organisation
Cyberteam
Location
London Area, United Kingdom
client. The ideal candidate will have extensive experience with C# and a passion for creating robust, scalable backend solutions. In this role, you will design and implement high-performance systems for Client’s fintech platform, making use of your expertise in .NET, database optimisation, and API design. … hear from you. You must have worked in the UK for a minimum of 3 years. No Visa and sponsorship offered. Key Responsibilities Software Design & Development Design, develop, and maintain secure, high-performance backend services using C# and the latest .NET/.NET Core frameworks Build and evolve ...

Artificial Intelligence Engineer

Hiring Organisation
HireWise
Location
City of London, London, United Kingdom
edge AI functionality across a flagship cybersecurity platform, building scalable, performant systems that harness the power of data, ML models, and infrastructure. Key Responsibilities: Design, develop, and deploy production-grade ML/AI features — from data prep and model training to inference APIs and monitoring. Integrate and scale LLMs … PyTorch and scikit-learn . Hands-on experience with state-of-the-art foundation models, embeddings, and RAG. Strong knowledge of cloud computing, microservices, API design, and event-driven architectures. Experience with Jupyter notebooks for data exploration and model iteration. About You: You are driven, empathetic, and thrive ...

Backend Engineer

Hiring Organisation
Searchability
Location
London, South East, England, United Kingdom
Employment Type
Full-Time
Salary
£50,000 - £75,000 per annum
architecture and deployments Exposure to cutting-edge AI and real-time data systems Fast-paced, collaborative engineering environment THE BACKEND ENGINEER ROLE: You'll design, build, and maintain high-performance APIs using Python and FastAPI, working with large volumes of live sports data. The systems are real-time … subject to required skills) your application to our client in conjunction with this vacancy only. KEY SKILLS Python, FastAPI, PostgreSQL, AWS, Docker, Backend Development, API Design, Real-Time Systems, Software Engineering, Sports Data ...

Back End Developer

Hiring Organisation
NearTech Search
Location
City of London, London, United Kingdom
influence architectural decisions at a critical stage of growth. The Senior Backend Engineer (Full Stack, backend-leaning) will take ownership of complex backend REST API Services and deliver scalable systems using TypeScript and Node.js . You will closely with Product, Engineering and Operations, working alongside the Lead Engineer … refine technical direction, improve delivery standards and elevate system reliability. The Senior Backend Engineer (Full Stack, backend-leaning) will... • Design and maintain scalable Node.js/TypeScript services and REST APIs • Own backend initiatives end-to-end, from architecture to rollout • Strengthen testing strategy across unit and integration layers • Improve ...

iOS Developer

Hiring Organisation
Expedia Group
Location
City of London, London, United Kingdom
architectural direction, influencing engineering standards, and shaping the evolution of AI-enabled capabilities across the mobile platform. In this role, you will: Lead the design, development, and maintenance of advanced iOS applications, ensuring high performance, quality, and responsiveness across Expedia Group’s product suite. Architect and implement robust, scalable … system and API designs, including effective data modelling to support complex business requirements. Drive cross-functional collaboration to define, develop, and ship impactful features, ensuring alignment with organisational goals and technical strategy. Champion best practices in software engineering, testability, and maintainability through code reviews and mentoring. Safely integrate ...

Full Stack Engineer

Hiring Organisation
Intellect Group
Location
London Area, United Kingdom
operations teams and field contractors across the UK. You will work on modern web applications using Python, Django, HTML, HTMX and React, contributing to API design, system architecture and end to end feature delivery. This is a high ownership role suited to someone comfortable working autonomously ...

Full Stack Engineer

Hiring Organisation
Intellect Group
Location
City of London, London, United Kingdom
platform used by clients, operations teams and field contractors across the UK. You will work across Python and Django on the backend, contributing to API design, system architecture and end to end feature delivery. The environment includes modern web technologies such as React and HTMX, supported ...

Lead AI Engineer

Hiring Organisation
Aturiya AI
Location
London Area, United Kingdom
Next.js. You've worked with LLMs in production - prompt engineering, evals, handling non-determinism. Not just tutorials. You have taste. You care about UX, API design, code structure - not because someone told you to, but because sloppy work bothers you. You default to action. When something's unclear ...

Mulesoft Developer

Hiring Organisation
Bridge Recruitment UK Limited
Location
Central London, London, United Kingdom
Employment Type
Permanent, Work From Home
Salary
£75,000
Salesforce MuleSoft Developer (Hybrid Role) Were looking for an experienced Salesforce MuleSoft Developer to design, build, and maintain integrations between Salesforce and external systems. Youll work closely with cross-functional teams to deliver scalable, high-performance integration solutions aligned with business needs. What youll do: Design, develop, test … 3+ years Salesforce experience Strong background in software development and OOP Hands-on MuleSoft & Salesforce integration experience MuleSoft certification(s) Solid understanding of API design and integration best practices Bachelors degree in Computer Science, Engineering, or related field Salesforce ecosystem experience is a strong plus. ...

Lead Full Stack Developer

Hiring Organisation
G.R.E. Recruitment Limited
Location
City, London, United Kingdom
Employment Type
Permanent
Salary
GBP 95,000 Annual
Start Up - Smart Living Platform Fully Remote - Must be UK based £85,000 - £95,000 + Stock Options (DOE) Essential Exp: Laravel, Flutter, SaaS, API Design, MySQL/PostgreSQL/MariaDB G.R.E. Recruitment is DELIGHTED and EXCITED to partner with an exciting UK based PropTech Start-Up company ...

Android Developer

Hiring Organisation
Expedia Group
Location
City of London, London, United Kingdom
setting architectural direction, influencing engineering standards, and shaping the evolution of AI-enabled capabilities across the mobile platform. In this role, you will: Architect, design, and deliver advanced Android mobile solutions, ensuring scalability, performance, and maintainability across Expedia Group’s travel platforms. Lead technical direction for multi-service … quality, and knowledge sharing. Safely integrate and operate AI/ML-enabled solutions that improve mobile user experiences and business outcomes. Collaborate with product, design, and engineering stakeholders to deliver innovative mobile features and drive technical strategy across the organisation. Minimum Qualifications: Bachelor’s degree in Computer Science ...