26 to 50 of 62 API Design Jobs in London

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 ...

team works with top tier global financial institutions and major tech companies to offer Wise products and services directly to their customers. Through our API, we help partners to architect and build integrations to our world class-leading international finance products, which in turn improves Wise Platform by increasing … improve turnaround times. Designing and developing innovative new features that expand the functionality of Wise's services and exposing these features through the public API, enabling seamless integration with partner systems and empowering them to leverage the full potential of Wise's platform. Diagnosing and resolving complex technical issues ...

foundational systems that power our embedded finance platform at global scale. The team owns multi‐tenant infrastructure, drives cross‐domain product capabilities, and helps design technical solutions for enterprise customers. Key areas of ownership include: Embedded Finance Platform: Build and maintain the infrastructure powering customers like Rippling, Navan, Qantas … career development. Set technical direction for scalable, reliable backend systems and partner with senior engineers on architecture and design. Ensure high standards for system design, code quality, testing, and operational excellence. Drive improvements across reliability, observability, security, and developer productivity. Work cross‐functionally with product, design, compliance, sales ...

Boomi AtomSphere, connecting multiple enterprise platforms across cloud and on-premise environments. This is a hands-on technical position requiring strong Boomi development experience, API integration knowledge and the ability to support complex integration landscapes. Key Responsibilities: Design and develop scalable integration solutions using Dell Boomi AtomSphere, including … secure Managed File Transfer (MFT) workflows to support high-volume and sensitive data transfers Publish, secure and govern REST/SOAP APIs through Boomi API Management, including gateway configuration, throttling and developer portal management Develop and maintain CI/CD pipelines using Git, Azure DevOps or Jenkins, supporting automated ...

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+ ...

.NET/C#,, NET Core and familiarity with SQL or data skills Proficiency in Front end tech stack React or Angular Understanding of system design, domain modelling, and API design principles Experience writing unit and integration tests and working with CI/CD pipelines Exposure to cloud ...

.NET 8/9 , with the ability to architect and lead distributed REST microservices. Strong authority across AWS serverless Lambda-first thinking, plus API Gateway, SQS, Step Functions, EventBridge and IAM. Hands-on experience with Claude Code (or similar) and agentic engineering: multi-agent orchestration, context management, custom skills … scaling AI-assisted delivery. Deep data expertise across Aurora MySQL and DynamoDB schema design, access patterns, indexing, tuning and pragmatic trade-offs. Proven experience designing event-driven systems with SQS: idempotency, retries, ordering, DLQs and operational resilience. Strong API design sensibility: versioning, documentation, throttling, backwards compatibility ...

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 ...

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 ...

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 ...

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 ...

Inside IR35 12 month contract ASAP start date Hybrid - as and when required in London (infrequent travel) Skillset: Background in Software Architecture API design (REST is preferable). ++ Designing for use with User Interfaces would be a plus. Event-driven architecture patterns Familiarity with AWS and Kubernetes ...

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 ...