26 to 50 of 58 API Design Jobs in London

this is an opportunity to help shape the future of a rapidly evolving platform. Role The Full Stack Developer will contribute to full-stack design and development across the platform. Design, develop, and maintain both front-end user interfaces and back-end services, APIs, and databases. Monitor platform … strong focus on backend development. Bachelor's or Master's degree in Computer Science, Engineering, or a related discipline. Strong understanding of database design, data modelling, and optimisation, particularly using SQL. Hands-on experience working with Google Cloud Platform (GCP) services. Experience monitoring production systems, triaging issues, and distinguishing ...

enjoys building from the ground up. The salary range is up to £120,000 depending on experience and fit. Key Responsibilities Own the design, development, and operation of the core backend services that power our consumer-facing products and internal operational tooling. Build scalable, low-latency systems that … notification preferences, audience segmentation, and delivery tracking. Integrate with third-party data providers and external services, ensuring robust failure handling, observability, and system resilience. Design and support secure internal tooling APIs, including role-based access controls, audit trails, change history, and safe administrative workflows. Build and operate event-driven ...

regulatory, and technical domains—areas where no single existing team has full coverage, like tax systems, compliance-driven flows, or monetization tools. Solutions Architecture: Design integrations for enterprise prospects by translating their business requirements into technical solutions. Your architectural decisions directly influence deal outcomes—from enabling multi-million dollar … 8+ for Staff) in Java/Spring Boot Excel at making the right level of abstraction—balancing flexibility and simplicity in system/component design Demonstrate clean communication across technical and non-technical stakeholders Make pragmatic decisions on when to optimize for performance vs. velocity based on business impact ...

What were looking for: Hands-on experience running real production workloads on AWS not just deploying to it Strong Postgres/SQL skills: schema design, query tuning, migrations Solid API design chops: clear contracts, versioning, backwards compatibility Python-first mindset (FastAPI or similar) Redis experience: caching patterns ...

stage (ambiguous) environments. You've seen products through from v1 to scale, and you love designing clean systems that last. Your mission is to Design, develop, test, deploy, maintain, and enhance practical AI-powered software solutions for the fintech industry. Own project timelines by managing priorities and delivering high … cloud platforms (AWS/GCP) Strong experience with designing, building and scaling distributed systems Strong background in relational + non-relational databases (PostgreSQL, Redis) API design chops (REST, GraphQL), deployment know-how Bonus Points If You Have built complex workflow orchestration systems Know your way around cloud infra ...

lead a team of elite engineers who embed directly with Fortune 500 customers to ship deeply integrated AI agents—owning everything from agent design and evaluation to the backend services, data systems, and cloud infrastructure that make them production-ready. You'll partner closely with our Forward Deployed … volume for senior engineering roles. Hands‐on fluency with the full AI stack. Deep familiarity with LLMs and agent systems, evaluation frameworks, backend and API design (Python or TypeScript), data systems (PostgreSQL, DynamoDB, MongoDB, or similar), and cloud infrastructure (AWS, Azure, or GCP) including Kubernetes, Docker ...

Tech Lead, Senior Software Engineer or Software Architect who enjoys solving complex technical problems and building modern, scalable software. Role & Responsibilities Lead the technical design and evolution of a large-scale business-critical platform. Improve the existing architecture and define a pragmatic roadmap towards a modern, scalable solution. Design … powered capabilities into the product to improve functionality and user experience. Drive the adoption of AI-assisted software development tools and engineering best practices. Design integrations with enterprise platforms, APIs and wider business systems. Work closely with Product, Architecture and Engineering teams to deliver incremental improvements. Mentor developers ...

Chicago). The role offers the opportunity to contribute to business-critical systems while working in a collaborative and supportive environment. Key Responsibilities Design, develop, enhance, and maintain enterprise applications using C# and .NET technologies. Support and improve existing business-critical systems, ensuring stability, performance, and scalability. Work closely … with business users, analysts, and technical teams to gather requirements and deliver solutions. Participate in the full software development lifecycle, including design, development, testing, deployment, and support. Collaborate with globally distributed development teams across multiple locations and time zones. Contribute to technical discussions, solution design, code reviews ...

Chicago). The role offers the opportunity to contribute to business-critical systems while working in a collaborative and supportive environment. Key Responsibilities Design, develop, enhance, and maintain enterprise applications using C# and .NET technologies. Support and improve existing business-critical systems, ensuring stability, performance, and scalability. Work closely … with business users, analysts, and technical teams to gather requirements and deliver solutions. Participate in the full software development lifecycle, including design, development, testing, deployment, and support. Collaborate with globally distributed development teams across multiple locations and time zones. Contribute to technical discussions, solution design, code reviews ...

client data will be sourced, validated, and integrated into Mondra, leveraging where possible our existing Import and Export APIs and identifying where custom API development may be required for fulfil Mondra’s data requirements. You will also contribute to the client contracting process, ensuring technical commitments are clearly defined … including mapping data sources, transformation logic, and validation processes. Identify the client’s BI requirements, and define data export strategies (preferably via existing Mondra API). Identify the authentication/authorisation capabilities of the client, and promote the integration with Mondra’s Identity Provider via Single Sign On. Leverage ...

Tech Lead, Senior Software Engineer or Software Architect who enjoys solving complex technical problems and building modern, scalable software. Role & Responsibilities Lead the technical design and evolution of a large-scale business-critical platform. Improve the existing architecture and define a pragmatic roadmap towards a modern, scalable solution. Design … powered capabilities into the product to improve functionality and user experience. Drive the adoption of AI-assisted software development tools and engineering best practices. Design integrations with enterprise platforms, APIs and wider business systems. Work closely with Product, Architecture and Engineering teams to deliver incremental improvements. Mentor developers ...

evolve our stack and make constant improvements. Required Skills/Experience Strong C# development experience Experience with both .NET Core and .NET Web API Experience of building Microservices in .Net Core Experience using Message Based Architectures Experience using both SQL & NoSQL technologies Experience of API design Cloud ...

division. This position falls under our Cross Border line of business and is located in London. In this role, you will contribute to the design and development of our eMoney and FX payment systems. You will report directly to the Engineering Manager and collaborate closely with Product, Design … will set you up for success by providing: Assigned workspace or home office setup Company-issued equipment Role Responsibilities Provide significant contribution to the design, development, and maintenance of secure and scalable payment systems. Collaborate with engineering managers, designers, and product teams to gather and analyse requirements, implement technical ...

features-you will be building impactful, user-facing applications from day one. Working closely with the founding team, you will help architect robust APIs, design intuitive frontend interfaces, and integrate cutting-edge AI/ML models into our core product. Qualifications & Experience Essential: 0-2 years of hands … projects). Education: A degree in Computer Science, Information Technology, or a related discipline. Core Fundamentals: A solid grounding in web development fundamentals, REST API design, and secure coding practices. Frontend: Proficiency in React and TypeScript, with a clear sense of how to build maintainable component hierarchies. Backend ...

Data & ML Pipelines: Model data for strict auditability, versioning, and efficient querying, feeding structured datasets directly into downstream machine learning models. Empower Internal Teams: Design and implement intuitive, responsive web interfaces that allow non-technical stakeholders (Legal, Operations, Trust & Safety) to author and manage content policies with robust approval … services using Java, Kotlin, or Go . Modern Frontend Skills: Hands-on experience building clean, intuitive internal tooling using React and TypeScript . System Design & Integrity: Deep understanding of API design, backward compatibility, and data modeling for complex, versioned systems where stability is critical. Data Savvy: Experience ...

across the business, embeds intelligent automation into products and workflows, and uses modern AI tools to accelerate engineering and innovation. What you'll do Design and build scalable backend services in Python (FastAPI or similar). Own cloud infrastructure across AWS (GCP experience a bonus). Build secure APIs … with product, data and client teams. What we're looking for Proven experience building and operating production backend systems at scale. Strong Python, Postgres, API design and AWS expertise. Experience with Redis, CI/CD and cloud-native architectures. A genuine AI advocate with experience using ...

across the business, embeds intelligent automation into products and workflows, and uses modern AI tools to accelerate engineering and innovation. What you'll do Design and build scalable backend services in Python (FastAPI or similar). Own cloud infrastructure across AWS (GCP experience a bonus). Build secure APIs … with product, data and client teams. What we're looking for Proven experience building and operating production backend systems at scale. Strong Python, Postgres, API design and AWS expertise. Experience with Redis, CI/CD and cloud-native architectures. A genuine AI advocate with experience using ...

develop new features, enhance existing systems, and ensure our platform remains stable and efficient. Your deep understanding of Rails architecture, PostgreSQL optimisation, and API design will be essential as you contribute to ongoing development projects. If you enjoy collaborating in Agile/Scrum environments, value clean code ...

delivering multiple major milestones of products. Experience building scalable distributed systems running in public and/or private cloud environments. Knowledgeable of REST, API design patterns and microservices. Experience managing Full stack development teams, engineers working on UI Development and backend services. Familiarity with Container orchestration technologies ...

Autogen, Google ADK). Architecting RAG pipelines, vector database integrations, and prompt management strategies. Building guardrail frameworks to prevent hallucinations, injection and bias. Designing API-first and event-driven architectures. Influencing enterprise roadmaps, governance forums and technical standards. Partnering with senior engineers, value streams, and product stakeholders. What … bring Expertise in Azure AI, AWS Bedrock or Google Vertex. Strong experience with LLM evaluation/MES frameworks. Deep knowledge of integration security, API design and cloud-native patterns. Experience delivering solutions in regulated environments (desirable). Naturally proactive, consultative and comfortable influencing at senior levels. TPBN1_UKTJ ...

products (e.g., Concierge an agentic AI workflow tool, Prism a Mercer knowledge fabric for scheme data, and similar initiatives), from problem framing and design through build, release, and support. Translate risk advisory/consulting needs into clear technical requirements, user stories, and solution designs; partner with stakeholders through … Proven experience as a Tech Lead/Lead Engineer delivering production software, including hands-on coding and code review ownership. Strong backend engineering skills (API design, data modelling, performance) and experience building secure, role-based applications. Experience working directly with business stakeholders in a financial firm, with ...

Chicago). The role offers the opportunity to contribute to business-critical systems while working in a collaborative and supportive environment. Key Responsibilities Design, develop, enhance, and maintain enterprise applications using C# and .NET technologies. Support and improve existing business-critical systems, ensuring stability, performance, and scalability. Work closely … with business users, analysts, and technical teams to gather requirements and deliver solutions. Participate in the full software development lifecycle, including design, development, testing, deployment, and support. Collaborate with globally distributed development teams across multiple locations and time zones. Contribute to technical discussions, solution design, code reviews ...

maps, filters, and recommendations across multiple lines of business such as lodging, cars, activities, flights and packages. 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 modeling to support complex business requirements. Drive cross-functional collaboration to define, develop, and ship impactful features, ensuring alignment with organizational goals and technical strategy. Champion best practices in software engineering, testability, and maintainability through code reviews and mentoring. Safely integrate ...

heavily backend-biased position but given the size of the team you will be working across the stack when needed Build scalable, performant systems Design and deliver end-to-end features with direct impact on customer value Work with product and ML teams to help translate abstract and complex … software function About you: Strong ability across scalable and performant systems You have a product mindset Statically typed language expertise Experience with API design Low ego and love of engineering Full details are available. Please don't hesitate to get in touch for more information. ...

Central London (Hybrid, 3 days in-office) Engagement: Contract with potential to convert to permanent Rate: Competitive The Role: You will join a critical API team responsible for high-throughput backend services and real-time payment routing decisions. This is foundational infrastructure where your work directly affects payment acceptance … complex services in production. Production-level expertise in Go and/or Java. Experience building or maintaining high-volume, low-latency distributed systems. Strong API design skills. Hands-on experience with AWS cloud-native deployment. A systems-thinking approach to performance, correctness, and failure modes under load. Background ...