1 to 25 of 70 API Design Jobs in London

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 ...

confidence. You’ll play a key role in bridging backend data with frontend interfaces while helping shape new initiatives across the product landscape. Responsibilities Design and develop APIs that standardise access to complex internal datasets (ideally using NestJS, TypeScript, Kong) Apply thoughtful design practices including API versioning … Qualifications Strong experience with modern JavaScript and TypeScript on both backend (Node.js/NestJS) and frontend (React/Redux) Required Skills Solid understanding of API design principles (auth, scalability, security) Ability to work with diverse data formats such as CSVs, JSON, lists, etc. Experience writing complex database queries ...

Build agents that can verify the quality of the code and identify error patterns. Hypothesize on steps in the software engineering cycle (prototyping, architecture design, API design, production implementation, launch, experiments, monitoring, operational maintenance) and evaluate model capabilities on them Design verification mechanisms that can automatically … . Strong expertise in building full-stack applications and deploying scalable, production-grade software using modern languages and tools. Deep understanding of software architecture, design, development, debugging, and code quality/review assessment. Excellent oral and written communication skills for clear, structured evaluation rationales. Engagement Details: Commitment: flexible engagement ...

Build agents that can verify the quality of the code and identify error patterns. Hypothesize on steps in the software engineering cycle (prototyping, architecture design, API design, production implementation, launch, experiments, monitoring, operational maintenance) and evaluate model capabilities on them Design verification mechanisms that can automatically … . Strong expertise in building full-stack applications and deploying scalable, production-grade software using modern languages and tools. Deep understanding of software architecture, design, development, debugging, and code quality/review assessment. Excellent oral and written communication skills for clear, structured evaluation rationales. Engagement Details: Commitment: flexible engagement ...

scale - component lifecycle, rendering behaviour, and bundle architecture are instincts TypeScript mastery in strict mode - complex generics, discriminated unions, conditional types, and type-safe API boundary design Vite and modern build tooling; tree-shaking, chunk strategy, module federation, and build performance optimisation in CI State management at scale … composite lifecycle, memory profiling, GC pressure, and long-task detection WebGL, Canvas, or custom rendering engine for high-density, real-time financial data visualisation Design system ownership - token architecture, component API design, versioning strategy, and cross-team adoption at scale Testing discipline: unit, integration, E2E (Playwright/ ...

Role We’re hiring a Backend Engineer to build the core infrastructure behind Revax’s AI-native platform for professional services. You’ll design, optimise, and scale the systems that power multi-agent drafting, knowledge graphs, and auditable AI workflows used by accountants, tax advisors, and consultants at leading … graphs, and real-world enterprise workflows. What You’ll Do Build & own core backend systems · Build and optimise databases for complex, real-world data · Design and implement APIs using FastAPI for AI workflows and product features · Build and scale LangGraph-based multi-agent systems with checkpointing, retries, and observability ...

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 ...

pragmatic decision making Act as an escalation point for complex cross team technical challenges Ensure architectural decisions are clearly communicated, understood, and consistently applied Design and Innovation Define and maintain architectural patterns across backend services, APIs, data platforms, and front end systems Design scalable, resilient systems for analytics … data stores, favoring open standards and long term maintainability Architect distributed systems with focus on reliability, fault tolerance, and scalability Standards & Governance Establish API design standards ensuring consistency, discoverability, and ease of integration Define front end standards prioritizing web platform capabilities, progressive enhancement, and accessibility (WCAG) Create governance ...

will be a hands-on technical leader who defines direction, raises engineering standards, and delivers measurable product outcomes, all while remaining deeply involved in design and development. This is not a traditional people-management or delivery-management role—here, you will write code, architect solutions, lead complex projects … role is perfect for leaders seeking high-growth, product-driven environments, who are passionate about distributed systems, and who want to directly influence the design of secure, scalable, and resilient infrastructure while cultivating top engineering talent. What You'll Do: Architect and design scalable, resilient, high-performance backend ...

supporting GST. What you'll do Work as a full-stack software engineer, coding, developing, and testing applications using Golang and Python, across service, API, and automation layers Lead the strategic development and implementation of the AI Operations platform, driving AI-enabled software solutions for alert ingestion, correlation, automation … operational workflows Design, build, and operate software and automated testing frameworks on AWS, including unit tests, integration tests, API tests, and environment-based validation Document and maintain every aspect of applications and software, including design specifications, configuration, deployment processes, and troubleshooting runbooks Train, mentor, and oversee development ...

supporting GST. What you'll do Work as a full-stack software engineer, coding, developing, and testing applications using Golang and Python, across service, API, and automation layers Lead the strategic development and implementation of the AI Operations platform, driving AI-enabled software solutions for alert ingestion, correlation, automation … operational workflows Design, build, and operate software and automated testing frameworks on AWS, including unit tests, integration tests, API tests, and environment-based validation Document and maintain every aspect of applications and software, including design specifications, configuration, deployment processes, and troubleshooting runbooks Train, mentor, and oversee development ...

supporting GST. What you'll do Work as a full-stack software engineer, coding, developing, and testing applications using Golang and Python, across service, API, and automation layers Lead the strategic development and implementation of the AI Operations platform, driving AI-enabled software solutions for alert ingestion, correlation, automation … operational workflows Design, build, and operate software and automated testing frameworks on AWS, including unit tests, integration tests, API tests, and environment-based validation Document and maintain every aspect of applications and software, including design specifications, configuration, deployment processes, and troubleshooting runbooks Train, mentor, and oversee development ...

supporting GST. What you'll do Work as a full-stack software engineer, coding, developing, and testing applications using Golang and Python, across service, API, and automation layers Lead the strategic development and implementation of the AI Operations platform, driving AI-enabled software solutions for alert ingestion, correlation, automation … operational workflows Design, build, and operate software and automated testing frameworks on AWS, including unit tests, integration tests, API tests, and environment-based validation Document and maintain every aspect of applications and software, including design specifications, configuration, deployment processes, and troubleshooting runbooks Train, mentor, and oversee development ...

supporting GST. What you'll do Work as a full-stack software engineer, coding, developing, and testing applications using Golang and Python, across service, API, and automation layers Lead the strategic development and implementation of the AI Operations platform, driving AI-enabled software solutions for alert ingestion, correlation, automation … operational workflows Design, build, and operate software and automated testing frameworks on AWS, including unit tests, integration tests, API tests, and environment-based validation Document and maintain every aspect of applications and software, including design specifications, configuration, deployment processes, and troubleshooting runbooks Train, mentor, and oversee development ...

supporting GST. What you'll do Work as a full-stack software engineer, coding, developing, and testing applications using Golang and Python, across service, API, and automation layers Lead the strategic development and implementation of the AI Operations platform, driving AI-enabled software solutions for alert ingestion, correlation, automation … operational workflows Design, build, and operate software and automated testing frameworks on AWS, including unit tests, integration tests, API tests, and environment-based validation Document and maintain every aspect of applications and software, including design specifications, configuration, deployment processes, and troubleshooting runbooks Train, mentor, and oversee development ...

supporting GST. What you'll do Work as a full-stack software engineer, coding, developing, and testing applications using Golang and Python, across service, API, and automation layers Lead the strategic development and implementation of the AI Operations platform, driving AI-enabled software solutions for alert ingestion, correlation, automation … operational workflows Design, build, and operate software and automated testing frameworks on AWS, including unit tests, integration tests, API tests, and environment-based validation Document and maintain every aspect of applications and software, including design specifications, configuration, deployment processes, and troubleshooting runbooks Train, mentor, and oversee development ...

supporting GST. What you'll do Work as a full-stack software engineer, coding, developing, and testing applications using Golang and Python, across service, API, and automation layers Lead the strategic development and implementation of the AI Operations platform, driving AI-enabled software solutions for alert ingestion, correlation, automation … operational workflows Design, build, and operate software and automated testing frameworks on AWS, including unit tests, integration tests, API tests, and environment-based validation Document and maintain every aspect of applications and software, including design specifications, configuration, deployment processes, and troubleshooting runbooks Train, mentor, and oversee development ...

supporting GST. What you'll do Work as a full-stack software engineer, coding, developing, and testing applications using Golang and Python, across service, API, and automation layers Lead the strategic development and implementation of the AI Operations platform, driving AI-enabled software solutions for alert ingestion, correlation, automation … operational workflows Design, build, and operate software and automated testing frameworks on AWS, including unit tests, integration tests, API tests, and environment-based validation Document and maintain every aspect of applications and software, including design specifications, configuration, deployment processes, and troubleshooting runbooks Train, mentor, and oversee development ...

supporting GST. What you'll do Work as a full-stack software engineer, coding, developing, and testing applications using Golang and Python, across service, API, and automation layers Lead the strategic development and implementation of the AI Operations platform, driving AI-enabled software solutions for alert ingestion, correlation, automation … operational workflows Design, build, and operate software and automated testing frameworks on AWS, including unit tests, integration tests, API tests, and environment-based validation Document and maintain every aspect of applications and software, including design specifications, configuration, deployment processes, and troubleshooting runbooks Train, mentor, and oversee development ...

supporting GST. What you'll do Work as a full-stack software engineer, coding, developing, and testing applications using Golang and Python, across service, API, and automation layers Lead the strategic development and implementation of the AI Operations platform, driving AI-enabled software solutions for alert ingestion, correlation, automation … operational workflows Design, build, and operate software and automated testing frameworks on AWS, including unit tests, integration tests, API tests, and environment-based validation Document and maintain every aspect of applications and software, including design specifications, configuration, deployment processes, and troubleshooting runbooks Train, mentor, and oversee development ...

supporting GST. What you'll do Work as a full-stack software engineer, coding, developing, and testing applications using Golang and Python, across service, API, and automation layers Lead the strategic development and implementation of the AI Operations platform, driving AI-enabled software solutions for alert ingestion, correlation, automation … operational workflows Design, build, and operate software and automated testing frameworks on AWS, including unit tests, integration tests, API tests, and environment-based validation Document and maintain every aspect of applications and software, including design specifications, configuration, deployment processes, and troubleshooting runbooks Train, mentor, and oversee development ...

supporting GST. What you'll do Work as a full-stack software engineer, coding, developing, and testing applications using Golang and Python, across service, API, and automation layers Lead the strategic development and implementation of the AI Operations platform, driving AI-enabled software solutions for alert ingestion, correlation, automation … operational workflows Design, build, and operate software and automated testing frameworks on AWS, including unit tests, integration tests, API tests, and environment-based validation Document and maintain every aspect of applications and software, including design specifications, configuration, deployment processes, and troubleshooting runbooks Train, mentor, and oversee development ...

supporting GST. What you'll do Work as a full-stack software engineer, coding, developing, and testing applications using Golang and Python, across service, API, and automation layers Lead the strategic development and implementation of the AI Operations platform, driving AI-enabled software solutions for alert ingestion, correlation, automation … operational workflows Design, build, and operate software and automated testing frameworks on AWS, including unit tests, integration tests, API tests, and environment-based validation Document and maintain every aspect of applications and software, including design specifications, configuration, deployment processes, and troubleshooting runbooks Train, mentor, and oversee development ...

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 ...

GraphQL specialist ready to lead the integration layer of a major HR systems programme? Our client is seeking a Hasura DDN Integration Engineer to design and deliver a centralised integration platform connecting a core HR system with several external services. The project requires expertise in Hasura, GraphQL, and microservices … This is a hands-on contract role, ideally suited to a senior integration engineer with strong experience in Hasura DDN (or Hasura v2), GraphQL API design, and complex system integrations . The Role Working within a multi-vendor delivery environment, the successful candidate will take ownership ...