26 to 50 of 53 API Design Jobs in London

Senior Full Stack Engineer

Hiring Organisation
Space Executive
Location
London Area, United Kingdom
shaping the future of the product. What you’ll be doing: • Designing and building scalable microservices using Node.js (Nest.js) and React • Driving an API-first architecture with strong focus on service-to-service communication and contract testing • Owning features end-to-end, from idea to production with a strong … What they’re looking for: • Strong experience building distributed systems/microservices architectures • Deep hands-on expertise with Node.js and React • Solid understanding of API design, event-driven systems, and contract testing • Experience working in fast-paced, ambiguous environments • Passion for automation, clean code, and solving real customer ...

Data Architect

Hiring Organisation
Damia Group Ltd
Location
Chiswick, London, United Kingdom
Employment Type
Permanent
Salary
£70000 - £90000/annum
Align data architecture with security, compliance, and data governance requirements Lead the evolution of technical architecture documentation, models, and decision records Conduct architecture and design reviews with cross-functional teams Guide teams in the adoption of best practices in API design, modularity, cloud-native patterns, and event … driven systems Recommend data management best practices, covering data flows, architecture patterns, retention, archival, and purging strategies Coach and mentor engineers on data design, refactoring, and architectural reasoning Essential skills and experience: Proven experience designing and scaling enterprise-grade cloud data platforms (AWS preferred) Deep experience with AWS, Databricks ...

React Developer

Hiring Organisation
Robert Half
Location
London, South East, England, United Kingdom
Employment Type
Contractor
Contract Rate
Salary negotiable
data synchronisation strategies. * Ensure front-end performance is optimised through techniques such as code splitting, virtualisation, bundle optimisation, and rendering efficiency improvements. * Collaborate on API design through a Backend-for-Frontend (BFF) approach, ensuring clean, predictable data contracts. * Embed security-by-design principles into all front … delivering complex, enterprise-grade front-end applications from build through to production. * Strong understanding of front-end architecture, including scalable project structure, reusable component design, and maintainable code patterns. * Advanced TypeScript skills, including typing API responses, shared models, and robust component interfaces. * Experience working with modern state management ...

Software Engineer

Hiring Organisation
NearTech Search
Location
City of London, London, United Kingdom
agility with the backing of a well-established business. The Senior Back End Developer will... take ownership of backend engineering for a new API-first data intelligence platform. Role Highlights Design and build scalable backend systems from a true greenfield starting point Define architecture, balancing rapid delivery with … long-term scalability Develop API-first services for data-heavy, enterprise-grade applications Embed observability, metrics, and performance tracking from day one Collaborate within a small, high-autonomy team shaping a new product You Will Need Extensive backend development experience within data-driven B2B environments Strong programming skills ...

Full Stack Developer .NET React

Hiring Organisation
Young's Employment Services Ltd
Location
West London, London, United Kingdom
Employment Type
Permanent, Work From Home
Salary
£80,000
deployment, Azure Service Bus, Blob Storage SQL Server T-SQL, EF Core migrations, query optimisation Azure DevOps Repos, Boards, Pipelines, Test Plans REST API design and OpenAPI/Swagger documentation This is an exciting time to be joining our client with salary will be based on experience ...

Principal Engineer

Hiring Organisation
Arrive
Location
City Of London, England, United Kingdom
technical initiatives across multiple teams Experience designing scalable, high-performance systems Experience working with legacy or monolithic systems and modernising them Strong understanding of API design and distributed systems Knowledge of modern engineering practices, including CI/CD and DevSecOps Understanding of secure development practices such as OWASP ...

Junior Back-end Engineer

Hiring Organisation
ivee
Location
City of London, London, United Kingdom
maintain server-side logic using modern backend frameworks (e.g. Node.js, Python, Go) Work with APIs — designing, integrating, and maintaining RESTful endpoints Support database design and optimisation (e.g. PostgreSQL, MongoDB) Collaborate with front-end and product teams to deliver full-stack features Write clean, testable, and maintainable code Help improve ...

Senior Full Stack Engineer

Hiring Organisation
Access Computer Consulting
Location
City of London, London, United Kingdom
Employment Type
Contract
Contract Rate
£400 - £440/day
This role is designed for engineers who have built and operated large-scale systems end-to-end, not those with superficial exposure or purely design-focused experience. Candidates must have strong experience of Java Full Stack, React, Kubernetes & Docker. Experience in building responsive, component based user interfaces using modern … front end frameworks. Hands on expertise in API design and development (REST/JSON), including versioning and backward compatibility. Experience with UI testing, component testing, and front end build tooling. Experience in CI/CD pipelines, GitOps workflows, A/B testing strategies and also automating the workflows ...

Chief Technology Officer (CTO) at Telehealth Platform

Hiring Organisation
Jobleads-UK
Location
Greater London, England, United Kingdom
such as AWS, Google Cloud, or Azure and DevOps practices Knowledge of healthcare data privacy standards including GDPR and HIPAA compliance Skilled in architecture design for scalable, secure, and reliable systems Experience managing real‐time communication technologies like WebRTC and video consultation infrastructure Platform & Development Proficiency with modern … frameworks (React, Node.js, Next.js) and mobile development platforms (iOS, Android, React Native, Flutter) Familiarity with API design, microservices, and payment integration systems (e.g., Stripe) Leadership & Strategic Qualities 10+ years experience in software engineering with at least 5 years in senior technical leadership roles Demonstrated ability to build ...

Pricing & Market Data (Migration Specialist)

Hiring Organisation
HCLTech
Location
City of London, London, United Kingdom
Trading (Oil, Gas, or Power). Technology Stack : Deep Mastery: Gresham Asset Control (legacy) and Prime EDM. Architecture : Cloud-native migrations (AWS/Azure), API design, and SQL/NoSQL performance tuning. Scripting : Python (preferred) or Java for custom business logic and automation. Pricing Logic : Strong understanding ...

Senior Backend Engineer

Hiring Organisation
Searchability®
Location
London Area, United Kingdom
Experience working on the engineering team in a start-up, scale-up or product-driven company Strong understanding and experience with building and consuming API-driven solutions. Experience with database technologies, cloud platforms (e.g., AWS, Azure, GCP), and API design principles. A minimum of a Bachelor ...

Back End Developer

Hiring Organisation
Albert Bow
Location
London Area, United Kingdom
+ mobile applications Building and maintaining high‐performance APIs and distributed microservices Solving problems around scalability, reliability, security, and automation Working with modern API protocols including GraphQL and gRPC Enhancing the platform that connects both traditional and on‐chain financial services Must‐have experience: Strong backend engineering background with …/or Golang Solid understanding of microservices, event‐driven systems & distributed architecture Strong knowledge of PostgreSQL and/or Redis Understanding of web semantics, API design & backend web standards Proficiency with Git and version control workflows Experience with CI/CD, build automation and modern engineering pipelines Excellent ...

Mid-Senior Ruby on Rails Engineer (B2B SaaS | Hybrid | UK)

Hiring Organisation
Transreport
Location
London Area, United Kingdom
architecture Extensive experience with PostgreSQL, including performance tuning and complex queries. Experience with background job processing using Sidekiq and Redis. Solid understanding of RESTful API design, JSON serialization, and authentication (e.g., JWT, SSO). Hands-on experience with AWS services and containerised deployments (Docker). Experience troubleshooting ...

AI Platform Engineer

Hiring Organisation
The Portfolio Group
Location
London, Castle Baynard, United Kingdom
Employment Type
Permanent
Salary
£75000 - £85000/annum
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
London Area, 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. ...

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 ...

Backend Software Engineer (Python)

Hiring Organisation
SR2 | Socially Responsible Recruitment | Certified B Corporation™
Location
City of London, London, United Kingdom
engineering hires, you will play a key role in building and scaling the core platform , working closely with the CTO and senior engineers to design, develop and deploy new features. This is a hands-on role with real ownership and impact on product direction. Requirements 2+ years of commercial … production web applications (not just data science scripts) Experience with Docker and containerised applications Experience working with relational databases (e.g. PostgreSQL) Good understanding of API design and backend architecture Proficiency with Git Willingness to work 2 days per week onsite in London Nice to have Exposure ...

Principal Java Engineer

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 Backend Engineer

Hiring Organisation
Rise Technical Recruitment
Location
Fulham, 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 ...

Enterprise Architect – Product Inventory Domain

Hiring Organisation
Jobleads-UK
Location
Greater London, England, United Kingdom
technology and business strategy. You will work with the business on ideation and discovery for key strategic Commercial initiatives and provide high level solution design for those initiatives. The role involves collaboration with domain solution architects and the wider architecture team, all reporting to the Head of Architecture. … technology landscape, identifying patterns and standards, and ensuring artefacts and decisions are well documented and governed. Key Skills & Qualifications Experience of pragmatic architecture governance, design governance, production of enterprise artefacts, and maintenance of architecture viewpoints. Demonstrable experience leading major initiative discovery and experimentation. Demonstrable experience designing high-quality software ...

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 ...

Senior Android Engineer - Hybrid, £100K

Hiring Organisation
Oliver Bernard
Location
City of London, London, United Kingdom
share code with iOS. You’ll be joining a collaborative engineering group working on major new features, shaping technical discussions, influencing architecture and API design, and helping to evolve a category-defining product used across the UK, US and several new international markets launching in 2026. What they ...

Enterprise Architect – Digital

Hiring Organisation
Jobleads-UK
Location
Greater London, England, United Kingdom
Technology Team at easyJet Holidays. The team is a dynamic group of practical and pragmatic architects responsible for providing strategic technology decisions, providing solution design and being the custodians of architecture information across the organisation. Job Purpose As the Enterprise Architect for the Digital Domain, you will be responsible … working with our business on aiding ideation and discovery for key strategic Commercial initiatives. You will also be responsible for high level solution design for those key initiatives. The role will involve working with domain solution architects who are dedicated to solution design and the wider team comprising ...

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 ...

Lead backend Kotlin/Java engineer

Hiring Organisation
CryptoStars Traders
Location
City of London, London, United Kingdom
Web3 space, our roadmap includes future decentralised integrations – so an interest or background in blockchain technology is highly desirable. Key Responsibilities Lead the software design and development of our next-generation trading engine. Oversee a codebase primarily written in Kotlin, with additional components in Python, Flutter, and SQL. Implement … robust security protocols and cryptographic solutions to protect financial transactions and user data. Design and maintain high-performance financial algorithms. Collaborate with our international platform development and product teams to deploy services onto our cloud-agnostic developer platform and maintain cyber security. Mentor other engineers, fostering a culture ...