26 to 50 of 53 API Design Jobs in London

exciting opportunity now available with one of our sector-leading retail clients! They are currently looking for a highly skilled MuleSoft Developer to design, build, and deliver MuleSoft APIs for a complex retail and E-commerce implementation. The role involves hands on development, and design experience within … agile, multi squad environment Job Responsibilities/Objectives Design, develop, test, and maintain MuleSoft APIs and integrations aligned to an API-led connectivity approach (Experience, Process, and System layers). Build and expose RESTful and SOAP APIs in compliance with agreed interface contracts and enterprise API design ...

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 ...

building and knowledge-sharing initiatives Skills & Experience Required Significant senior backend development experience with strong Python proficiency (async programming, concurrency, multithreading) Expertise in RESTful API design, OpenAPI/Swagger documentation and API lifecycle best practices Hands-on experience with ML libraries: PyTorch, PySpark, scikit-learn, Hugging Face … machine learning, cloud computing or data engineering highly advantageous Professional accounting qualification desirable but not required Nice to Have Experience with Microsoft Graph API Background in audit, financial services or regulated industry technology What's on Offer A competitive salary and benefits package, flexible hybrid working across 20+ ...

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 ...

months - Hybrid - INSIDE IR35 I am working with a client who are seeking an experience Enterprise Architect with strong background in leading the architectural design for the replacement of legacy systems (ORACLE) Key Responsibilities: 'As-Is' Architecture Baseline Target State Design Integration Strategy & API Design Transition ...

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 ...

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 ...

product mission by partnering with stakeholders to define strategy, technical architecture, product roadmap, and execution plans. Champion high code quality, scalable and resilient system design, and customer focus across the team. Lead by example, fostering a culture of innovation and ownership. Participate in on‐call rotation every four weeks. … teams of 6+ individual contributors, delivering major product milestones. Experience building scalable, distributed systems in public or private cloud environments. Strong knowledge of REST, API design patterns, and microservices. Experience managing full‐stack development teams (UI and backend services). Familiarity with container orchestration, deployment models, modern ...

role, with strong backend expertise in Typescript and Node and front capability in React Proficiency in SQL, Redux, cloud services (AWS or GCP), RESTful API design and GraphQL Strong analytical skills with the ability to design, optimise, and troubleshoot complex UIs Excellent communication and leadership skills; ability ...

LangChain or LangGraph (agent memory, tool calling, state management) Dagster in production (assets, sensors, partitions) or equivalent pipeline orchestration Strong backend fundamentals including API design, async programming, and database modelling You've built systems that had to work reliably at scale, not just pass a demo Experience 5+ ...

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 ...

work within a small, close-knit team of 4-6 people, involved in every part of the development life cycle, from analysis and design through to testing and production support. We don't separate these functions out across different teams; the team that builds it is the team that … builds a feature also supports it Identify areas of technical debt and help prioritise a healthy balance between addressing debt and delivering new functionality Design solutions for new work in line with technology guidelines and architectural constraints Pair regularly with other members of the team to share knowledge ...

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 ...

improving APIs that support critical platform functionality Investigating production issues and tracing problems across distributed systems Working with product and engineering teams to design scalable solutions Improving reliability, observability and performance across existing services Reviewing code, sharing knowledge and helping raise engineering standards across the team Tackling real-world … APIs used by customers or internal teams Other Skills Needed: Solid backend engineering experience in C#, Java, or Go, with a strong grasp of API design and architecture. Hands-on experience managing and debugging production systems across cloud and self-managed infrastructure. Proven ability to navigate complex third ...

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 ...

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 ...

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 ...

ENGINEER Leading Investment House| London | Contract Role THE ROLE Design and build core AI platform components for a leading buy-side investor. You'll own the LLM gateway, MCP connector layer, observability tooling, and privacy proxy translating business use cases into governed, production-ready AI systems . WHAT … Design and maintain LLM gateway, MCP connector layer, observability, and privacy proxy Develop MCP connectors across data sources (M365, Salesforce, Kensho, Moody's, internal systems) Build AI-powered tools and workflows for business teams Integrate Databricks/Unity Catalog as data foundation for AI features Write clear specifications before ...

Data platforms - Fabric, Snowflake, CosmoDB, DataBricks, MongoDB, RDBMS Data replication/CDC - Qlik Replicate, Oracle Golden Gate Data modeling - ERStudio Message-oriented data movement API design and access Data Analytics and AL/ML - AzureML Data virtualization Streaming data Data integration and ETL/ELT Tools - Matillion, Alteryx … NoSQL data stores, methods, and approaches (star and snowflake, dimensional modelling and third normal form) Experience with data security and data access controls and design Deep understanding of SoX, GDPR and Regulatory/CNI control environments In-depth experience in providing resolution to an extensive range of complicated data ...

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 ...

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 ...

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 reach out for more information. ...

structured, actionable work that delivers measurable outcomes. You'll work across the full analysis lifecycle—from stakeholder engagement and discovery through to requirements, process design, delivery support and benefits realisation. The role suits someone who pairs strong analytical and requirements discipline with the facilitation skill to align stakeholders … operations colleagues to embed new ways of working (Technical/Systems BA) Bridge between business stakeholders and engineering—data flows, integrations, system behaviour, API design from a functional perspective (For Senior/Lead/Head of) Set BA standards and practice, mentor analysts, lead larger transformation and change ...

Live platform Contributing to a shared transaction layer used across multiple products Collaborating with frontend and mobile engineers to deliver consistent experiences Key Responsibilities Design and build backend services end-to-end Contribute to platform and API design decisions Improve system performance and reliability Work within … evolving architecture with real production constraints Profile The Backend Engineer will have strong API and service development skills Experience working on transaction systems, payments, or eCommerce platforms is required Experience with GraphQL preferred Exposure to Elixir, Go, or similar backend technologies Ability to work effectively in ambiguous, fast-changing ...