1 to 25 of 126 Permanent API Design Jobs in the UK

office) About the Role We're looking for a Senior Application Engineer with strong backend and cloud development expertise to help design and build scalable, secure services that power Internal Platforms. What You'll Do Design and build scalable backend services and APIs supporting mobile and event-driven … requirements through deployment and maintenance Provide technical guidance and mentorship to engineers within the team Promote best practices such as TDD, BDD, and secure API design Collaborate with technical leads, IT teams, and business stakeholders to deliver high-quality solutions Apply design patterns and engineering best practices ...

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 ...

development aligns with OWASP secure coding standards Contributing to CI/CD pipeline improvements and secure deployment practices Participating in architecture and technical design reviews Collaborating with UI/UX teams using Figma prototypes Maintaining high-quality technical documentation Tech Stack & Experience Core technologies: .NET 10/ASP.NET Core … Entity Framework Core RESTful API design/OpenAPI/Swagger Angular 21 (mandatory) TypeScript/RxJS DevExpress DevExtreme v25 (mandatory) Microsoft Azure (App Services, SQL, Storage) Azure Entra ID Azure Key Vault Infrastructure as Code (Bicep preferred) CI/CD pipelines (Azure DevOps or equivalent) Bitbucket (Git) What ...

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 … experience. 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 … experience. 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 … experience. 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 … experience. 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 … experience. 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 … experience. 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 … experience. 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 … experience. 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 … experience. 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 … experience. 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/ ...

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 ...

built. You'll also play a mentorship role - raising the engineering bar across the team and championing Responsible AI practices as we scale. Responsibilities Design scalable, secure, and fault-tolerant full-stack architectures that seamlessly blend traditional web services with generative AI components, ensuring high availability and resilience across … cost-optimised use of Azure AI APIs, GPU compute, and container orchestration resources Set the standard for code quality through comprehensive code reviews, technical design documents, and architectural decision records; mentor junior and mid-level engineers to grow their capabilities hampion Responsible AI practices including model evaluation, bias monitoring ...

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 ...

SoftwareDeveloper(API Development/Backend Node.js, C#, Fullstack) Birmingham, West Midlands (Hybrid 1 day onsite a week) 55k + Benefits Were partnering with a leading enterprise software house in Birmingham that is expanding its engineering team. Theyre looking for a Software Engineer with strong API and backend development … power enterprise software products. Youll work primarily with Node.js and C#, collaborating with cross-functional teams to deliver well-architected, maintainable solutions. Key Responsibilities Design, build, and maintain RESTful APIs and backend systems. Develop high-quality, scalable code using Node.js and C#. Collaborate with product and engineering teams ...

Software Developer (API Development/Backend – Node.js, C#, Fullstack) Birmingham, West Midlands (Hybrid – 1 day onsite a week)55k + BenefitsWe’re partnering with a leading enterprise software house in Birmingham that is expanding its engineering team. They’re looking for a Software Engineer with strong API … enterprise software products. You’ll work primarily with Node.js and C#, collaborating with cross-functional teams to deliver well-architected, maintainable solutions. Key Responsibilities Design, build, and maintain RESTful APIs and backend systems. Develop high-quality, scalable code using Node.js and C#. Collaborate with product and engineering teams ...

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 ...

Tailwind CSS to deliver end-to-end features. Data Architecture: Deep experience with diverse data stores, specifically PostgreSQL , ElasticSearch , and NoSQL (MongoDB), including schema design and performance tuning. System Design: Expert knowledge of RESTful API design and complex asynchronous request handling . Technical Leadership: Experience ...

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 ...

play a key role in shaping Bidwells’ digital transformation! Working closely with our Director of Technology & Innovation and Senior Solutions Architect, you’ll design, build and deploy modern web applications that drive efficiency, enhance client service and enable data‐driven decision making across the business. A key part … modern JavaScript (ES6+). Hands-on experience with Microsoft Azure services (App Service, Functions, Container Apps, SQL Database). Strong understanding of RESTful API design, microservices architecture and enterprise system integrations. Experience working with SQL databases and ORM frameworks. Familiarity with Git and CI/CD pipelines (Azure ...