1 to 25 of 53 API Design Jobs in London

Java/Microservices/API design/LLMs/AI/Claude Code/Copilot Company: Financial Services Location: London - Hybrid 3 days per week CORE BANKING AND TRADING SYSTEMS EXPERIENCE ESSENTIAL Join a newly formed Service Modernisation & AI team driving AI-first software development in financial services. … development tools (e.g. Claude Code, GitHub Copilot, LLMs) Experience with MCP, AI automation, or agentic AI systems Strong understanding of microservices and API design Java/Microservices/API design/LLMs/AI/Claude Code/Copilot ...

years of Web application development experience consisting of strong C#, ASP.NET MVC 5, and React. Strong knowledge of Object-Oriented Programming, SOLID principles, common design patterns and RESTful API design and integration (experience with SOAP WebServices and XML/XPat) also required. We are looking … Server, Entity Framework, and React experience desirable to have HTML5, CSS3, JavaScript, jQuery. * Strong knowledge of Object-Oriented Programming, SOLID principles, and common design patterns. * Experienced in RESTful API design and integration; experience with SOAP WebServices and XML/XPath. * Skilled in using IoC containers (Autofac, Ninject ...

across Expedia’s white-label and partner platforms. We’re building the next generation of video ad infrastructure, AI-powered tooling, and Rapid API integrations to deliver smarter, more engaging ad experiences. In this role, you will: Design, implement, and evolve high-quality software services and components, including … system design, low-level design, API design, and data modeling to support scalable, reliable products. Lead end-to-end delivery of complex technical features across services or domains, including requirements clarification, solution design, development, testing, deployment, and ongoing operational support. Collaborate closely with product, architecture ...

London office About The Client: Our client is a rapidly growing Infrastructure-as-a-Service (IaaS) provider driving digital transformation. Key Responsibilities: Architecture & System Design Design and evolve scalable backend services and product components. Make sound architectural decisions across APIs, services, and data layers. Lead delivery from design … high coding standards and test coverage. Contribute to code reviews and documentation. Mentor engineers and support technical growth. Collaboration Work closely with Product and Design to deliver scalable solutions. Communicate technical trade-offs and manage cross-team dependencies. Essential skills and requirements: Strong experience building production backend systems ...

shaping Meteor's digital future. Key Responsibilities Lead, mentor, and inspire a team of developers, fostering a culture of technical excellence and continuous improvement Design, develop, and maintain high-quality software solutions across the full stack Architect and implement systems using .NET, JavaScript, SQL, and modern frontend frameworks Oversee … API design and integrations, ensuring secure and efficient data exchange Translate business and stakeholder requirements into clear technical solutions Conduct code reviews and ensure adherence to coding, security, and quality standards Drive continuous improvement in development workflows, testing, and deployment practices Support the professional development of team members ...

infrastructure that allows clients to launch card programs anywhere in the world through a single integration. You will be responsible for a unified Global API and SDK suite that abstracts the complexity of regional payment networks. Whether a client is launching in Europe, North America, or APAC, your product … will provide a consistent, white-label experience. You will drive both the technical "how" (API/SDK design) and the strategic "where" (global expansion and regional issuing setups). What you’ll do: Unified Global API Strategy: Design and maintain a single, polymorphic API architecture ...

matters, through challenging projects which demand ambitious innovation and thought leadership. The Role As a Staff Engineer (Backend – Java), you will be lead the design and development of highly scalable, resilient, and performant backend systems. This role is suited for a hands-on technical leader who can set engineering … drive complex solutions across multiple teams. Your responsibilities: Technical Leadership Evolve the technical strategy and architectural direction for backend services and distributed systems. Design scalable, fault-tolerant, event-driven, and cloud-native backend architectures. Lead complex engineering initiatives spanning multiple teams, domains, or platforms. Provide deep hands-on expertise ...

their latest platform, provide technical expertise at both the architectural and hands-on development levels, and mentor junior team members. What You’ll Do: Design and build scalable payment applications and APIs Develop modern frontend interfaces and backend services Integrate with payment providers and financial systems Optimise database performance …/Angular), HTML5, CSS3 Backend: Python REST APIs Data: MySQL, PostgreSQL, Redis Cloud & DevOps: AWS, Docker, CI/CD, Kubernetes (nice to have) Architecture: API design, OAuth/JWT authentication, queues, webhooks, payment integrations Previous experience in Financial Services What We’re Looking For: Strong system design ...

GlobalLogic, a Hitachi Group Company and a leader in digital engineering. We help brands across the globe design and build innovative products, platforms, and digital experiences for the modern world. By integrating experience design, complex engineering, and data expertise - we help our clients imagine what’s possible … Experience with: Experience with Python for data pipelines, export services, ETL, reconciliation, profiling scripts Data quality assessment Apache Kafka PostgreSQL for data modelling, query design, migrations etc Data modelling and schema design REST API design Ideally you will have: Experience of C# to be able ...

venture backed by the strength and stability of an established business. Key Responsibilities End-to-end development of high-quality, scalable SaaS platforms from design through deployment and maintenance. Architect and implement robust backend services primarily using Python and PostgreSQL. Develop and maintain responsive, performant front-end applications with … Provide technical mentorship and leadership to development teams, fostering best practices in coding, testing, and deployment. Participate in code reviews, architecture discussions, and system design decisions. Troubleshoot and resolve complex technical issues across the full stack. Ensure software security, scalability, and performance are maintained at all times. Keep abreast ...

engineering discipline, independent problem-solving ability, and a commitment to building robust, scalable systems. You will work across modern cloud-native architectures, contribute to API and microservices development, and help drive best practices across the engineering organisation. Key Responsibilities Design, develop, and maintain high-quality Java applications using … Spring Boot. Build and optimise RESTful APIs and contribute to GraphQL service development. Develop cloud-native solutions using AWS services such as Lambda, API Gateway, DynamoDB, ECS, S3, and others. Contribute to microservices architecture, event-driven systems, and distributed design patterns. Implement CI/CD pipelines using tools ...

PostgreSQL, complex data modelling AI/ML : OpenAI integration, semantic search, conversational agents, unstructured data analysis and extraction Infrastructure : AWS (Lambda, ECS/EKS, API Gateway, S3) DevOps : Terraform, GitHub Actions, Helm, Infrastructure-as-Code Data Science : Graph analytics, data pipelines, ETL workflows, Jupyter notebooks Required Qualifications Software Development … understanding of async programming Experience with Poetry or similar Python dependency management tools Experience building RESTful APIs and micro-services Solid understanding of database design and optimisation (both SQL and NoSQL) Experience with graph databases (Neo4j preferred) or willingness to learn quickly Knowledge of event-driven architectures and message ...

Senior API/PHP Developer – Fully Remote (UK) – £80,000+ Venchr is partnering with a fast-growing SaaS company that’s redefining financial management in the luxury and yachting sector. Their platform unites accounting, payments, FX, and project management into a single, powerful ecosystem — helping clients worldwide streamline complex … operations with ease. They’re now seeking a Lead PHP Developer with a strong focus on API architecture and backend systems to join their fully remote UK-based engineering team. In this role, you’ll take ownership of designing, developing, and optimizing APIs that power mission-critical services. ...

Ireland providing specialist services to a wide range of blue-chip clients. The role We are seeking technical polyglots who enjoy both technical architectural design, hands-on coding and peer reviews, though also like the idea of the equally important social/client-facing aspect of the role. … development architecture as well as supporting business analysts and product owners in planning and story-mapping for new development. You will act as technical design authority (TDA) for delivery of technical stories and produce technical documentation artefacts to support the delivery process. Main Responsibilities Duties will include: The design ...

impact role delivering large-scale enterprise cloud transformation programmes using AWS. What the Role Involves: As an AWS Solution Architect (Integration Specialist) , you will: Design and deliver AWS cloud-native workloads using serverless, microservices, and containerised architectures Build scalable, resilient, and secure integration solutions across enterprise systems Develop … Salesforce, and Oracle What Youll Need: Hands-on experience as an AWS Solution Architect (Integration Specialist) with Lambda and Kubernetes (EKS) Strong knowledge of API design and security (API Gateway, OpenAPI, OAuth2, JWT) Experience with cloud-native frameworks such as Flask or FastAPI Solid understanding of Kubernetes ...

Term Contract (Initial 3 Months with possible extension) Role Summary We are seeking a hands-on Solution Architect (78 years experience) to lead solution design and architecture alignment for a multi-system Agentforce and Salesforce implementation within a large enterprise environment.. This is a highly collaborative, client-facing role … systems. Key Responsibilities Define and own end-to-end solution architecture across Salesforce, Data Cloud, and connected enterprise systems Analyze existing client architecture and design target-state architecture aligned to prioritized use cases Create architecture diagrams (logical, physical, integration flows) and document solution designs Design and govern API ...

Description: We are seeking a hands-on Solution Architect to lead solution design and architecture alignment for a multi-system Agentforce and Salesforce implementation within a large enterprise environment. This is a highly collaborative, client-facing role that requires working closely with multiple Client enterprise and domain architects, Salesforce … systems. Key Responsibilities Define and own end-to-end solution architecture across Salesforce, Data Cloud, and connected enterprise systems Analyze existing Client architecture and design the target-state architecture aligned to prioritized use cases Create architecture diagrams (logical, physical, integration flows) and document solution designs Design and govern ...

internal systems. You will work within cross-functional agile squads and are expected to contribute from day one with minimal ramp-up. Key Responsibilities: Design, develop, and deliver high-quality Java microservices in support of back-office platform integration Build and maintain RESTful and event-driven APIs supporting settlement … reconciliation, corporate actions, and custody workflows Integrate with third-party financial platform APIs and messaging systems Contribute to technical design discussions, architecture reviews, and solution documentation Write clean, well-tested, production-grade code with appropriate unit, integration, and contract testing coverage Participate in code reviews and uphold engineering standards ...

Role: Senior Web Application Developer (Full-Stack) Specialism(s): eCommerce, ASP.NET MVC 5, C#, React, Migrations, Microsites, Cloud-Native, HTML5/CSS3/JavaScript, API, CI/CD, IoC Containers, Agile Type: Contract, Daily Rate Duration: 3+ Months Location: London Pay Rate: £450 - £525 per day (Inside IR35 … ready environment. Role Requirements * Develop and maintain complex web solutions using ASP.NET MVC 5, C#, and React * Support migration activities, ensuring clean architecture, scalable design, and efficient implementation * Produce secure, maintainable, scalable, and fault-tolerant code following SOLID principles and OO design patterns * Contribute to front-end development ...

Java Full Stack Developer (React Mandatory) to join our team in London. This project is associated with one of the largest Bank. Key Responsibilities: Design, develop, and maintain robust, scalable, and high-performance web applications. Build responsive and dynamic user interfaces using React js. Develop backend services and APIs … hands-on experience with React js , Redux (or similar state management libraries). Solid understanding of HTML5, CSS3, JavaScript (ES6+) . Experience with RESTful API design and integration. Familiarity with databases such as MySQL, PostgreSQL, or MongoDB. Experience with version control systems like Git. Strong understanding of object ...

core stack includes: The Engine: Expert-level C# and .NET Core mastery. Architecture: Deep understanding of SOA (Service Oriented Architecture) and complex Object-Oriented design patterns. System Dynamics: Specialized knowledge of concurrency, asynchrony, and parallelism —essential for real-time transactional processing. Data & Web: High proficiency in SQL Server … API design, and modern front-end fundamentals (HTML/CSS/JS). Reliability: A strict practitioner of TDD (Test Driven Development) and robust CI/CD processes. Desired Innovations Our client is actively modernizing. Exposure to the following is highly valued: Cloud & Orchestration: Azure ecosystems, Docker ...

real customers and users across the world. What You’ll Do Own our engineering stack from MVP to scale — backend, frontend, infra . Design architecture, choose tools, and set engineering standards. Work directly with early users to iterate quickly. Collaborate with the founding team on strategy, hiring, and scaling … high-quality, user-focused features (that change Oceans and planet) fast. What We’re Looking For 5+ years of backend expertise in Go including API design, microservices architecture, gRPC/REST services, and database design (PostgreSQL, Redis). Frontend proficiency with React/Next.js, responsive design ...

could be the role for you! What You'll Have the Opportunity to Do: • Develop and execute AWS workloads using cutting-edge cloud patterns • Design expandable application solutions in sync with best practice for performance, resilience and cost • Set up and manage CI/CD pipelines and apply cloud … security principles • Work alongside different clients and multi-functional teams to deliver solutions • Produce premium design documentation • Build and tune system architectures to ensure reliable, scalable and maintainable solutions About The Candidate The right candidate for the role of AWS Architect will have/gain the following experience: • Appropriate ...

full-stack architecture—understanding patterns, quality standards, and modern best practices for both client and server-side development. Collaborate cross-functionally with Product Management, Design, QA, and Customer Success to understand requirements and deliver features in iterative cycles. Contribute to designing and implementing products that are easily monitored, maintained … backend, integrating quality into every build. Participate in discovery and experimentation, using insights from Product and Customer Success to understand customer needs. Contribute to API design, database schema development, and server-side logic implementation. What You Bring 5+ years building modern web applications with Angular for the frontend. ...

GlobalLogic, a Hitachi Group Company and a leader in digital engineering. We help brands across the globe design and build innovative products, platforms, and digital experiences for the modern world. By integrating experience design, complex engineering, and data expertise - we help our clients imagine what’s possible … working. Initially 6-9 months About the role: Experience with C#/.NET Additional languages highly desirable ie Java, Python React/TypeScript RESTful API design Apache Kafka PostgreSQL Git/GitHub workflows Experience with Kubernetes deployments; able to build CI/CD pipelines About you (ideally ...