1 to 25 of 94 Permanent API Design Jobs in England

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 ...

They're looking for Application Engineer(Backend cloud-based application development), with deep technical expertise and thought leadership. The ideal candidate: Strong experience of API design for mobile application with event driven architecture. Experience of building distributed scalable microservices using Java/Kotlin, Spring Boot, OAuth 2.0, Secure … API design. AWS, API Design, Automation testing. If this sounds like an interesting opportunity to you, feel free to apply for this position or drop me your CV at mohammad.sobee@harveynash.com ...

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 ...

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 ...

must be within a commutable distance to achieve this. Are you a seasoned Lead Developer ready to step up and take real ownership of API strategy, architecture, and delivery Do you thrive in environments where your voice matters, your decisions have impact, and your ability to drive efficiency … space that is scaling its digital product ecosystem. They are investing heavily in modernising and expanding their digital platforms, and they need a Lead API Developer who can steer backend/API development with both technical authority and clear communication.This isn’t just another coding role. This ...

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 ...

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 ...

digital transformation programme. With a rapidly growing customer base and multiple products operating across complex environments, the business is now strengthening its integration and API capability to ensure its platforms communicate seamlessly across internal systems, partners, and external services. This role sits within a highly collaborative engineering environment where … teams to enable reliable, secure, and high-performing integrations that support enterprise-level SaaS delivery. What You’ll Be Doing Designing and building scalable API-led integrations across a modern SaaS platform ecosystem Developing and maintaining RESTful APIs and event-driven integrations between internal services and third-party systems ...

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 ...

consulting company focused on building innovative solutions that address clients’ most complex digital transformation needs. Leveraging our holistic portfolio of capabilities in consulting, design, engineering, and operations, we help clients realize their boldest ambitions and build future-ready, sustainable businesses. With over 230,000 employees and business partners across … ever-changing world. Role Summary We are seeking an AI Architect with deep hands-on experience in AI/ML and Generative AI to design and govern end‐to‐end solutions across application, data, and infrastructure layers. The Architect will own reference architectures , lead solution shaping , and ensure responsible ...

will coordinate with the rest of the team working on different layers of the infrastructure. Therefore, a commitment to collaborative problem solving, sophisticated design, and quality product is important. Responsibilities Working in a team of Front-End engineers Writing clear & concise code Working closely with Back-End engineers Participate … architecture design code reviews API design with the Back-End engineers and other team members to establish more functional, cohesive code Create, maintain documentation while implementing the best coding practices standards Hands-on approach Participation in sprint rituals What you’ll need 6+ years experience developing large ...

that integrate development finance datasets (e.g. OECD, IATI, World Bank, IMF, WHO, etc.) into a unified knowledge graph. Scaling the Knowledge Graph, including schema design, data integration, and optimisations. Developing the data quality framework, implementing provenance tracking, quality indicators, coverage metrics, and automated testing so that every data point … Spanner through the Data Commons infrastructure, alongside BigQuery for internal analytical workloads and MySQL for supporting services. Key responsibilities: Data infrastructure and pipelines Design, build, and maintain open-source ETL/ELT pipelines that ingest, clean, transform, and deliver development finance data from multiple sources. Contribute to data modelling ...

automation, and continuous improvement-and they're looking for someone who shares that mindset. Key responsibilities as the Senior Back-End Software Engineer are: Design and develop backend services using Node.js and TypeScript , deployed in a cloud-native environment. Build and maintain GraphQL and REST APIs to support … team. Skills & Experience needed: Essential: Strong experience with Node.js and TypeScript Proven background in microservices architecture Solid understanding of GraphQL and RESTful API design Experience with SQL and NoSQL databases Familiarity with CI/CD, automated testing, and modern development workflows Desirable: Experience with Azure or other cloud ...

APIs, managing infrastructure with Cloudformation, and building modern user interfaces with React. You will work on a high-traffic system that handles billions of API calls, requiring strong attention to scalability, performance, and reliability. Key Responsibilities Design, develop, and maintain microservices and RESTful APIs (Node.js + AWS Lambda … Handle data and queries using relational databases (e.g., PostgreSQL) Collaborate in designing and developing the user interface using React Integrate and monitor AWS services (API Gateway, S3, CloudWatch, RDS, CloudFront, etc.) Ensure testability, code quality, and DevOps best practices Technical Requirements Minimum of 5 years of experience in full ...

delivering scalable, high-performance applications. This role requires deep technical expertise, strong architectural skills, and the ability to collaborate effectively across teams. Key Responsibilities Design, develop, and maintain robust full-stack applications and services. Architect and implement scalable cloud-based solutions leveraging AWS . Optimise system performance, reliability … Node.js . Proven experience with AWS and cloud-based architectures. Full-stack proficiency with modern frameworks (e.g., React). Solid understanding of software architecture, design principles, and microservices. Experience with serverless architecture, containers (Docker, Kubernetes), and CI/CD pipelines. Excellent problem-solving, debugging, and communication skills. Preferred Qualifications ...

core stack includes: The Engine: Expert-level C# and .NET Core mastery. Architecture: Deep understanding of SOA (Service Oriented Architecture) and complex Object-Oriented design patterns. System Dynamics: Specialized knowledge of concurrency, asynchrony, and parallelism —essential for real-time transactional processing. Data & Web: High proficiency in SQL Server … API design, and modern front-end fundamentals (HTML/CSS/JS). Reliability: A strict practitioner of TDD (Test Driven Development) and robust CI/CD processes. Desired Innovations Our client is actively modernizing. Exposure to the following is highly valued: Cloud & Orchestration: Azure ecosystems, Docker ...

suited to an experienced consultant who enjoys setting technical direction, mentoring engineers, and acting as a trusted technical partner to clients. Responsibilities Lead the design and delivery of full stack JavaScript solutions Set technical direction, standards, and best practices across projects Remain hands-on, contributing to critical areas … Required Experience Extensive commercial experience with JavaScript/TypeScript Strong front-end experience with React (or equivalent) Strong back-end experience with Node.js and API design Proven experience in a Lead/Tech Lead/Senior Consultant role Experience designing and delivering scalable systems Strong stakeholder management ...

suited to an experienced consultant who enjoys setting technical direction, mentoring engineers, and acting as a trusted technical partner to clients. Responsibilities Lead the design and delivery of full stack JavaScript solutions Set technical direction, standards, and best practices across projects Remain hands-on, contributing to critical areas … Required Experience Extensive commercial experience with JavaScript/TypeScript Strong front-end experience with React (or equivalent) Strong back-end experience with Node.js and API design Proven experience in a Lead/Tech Lead/Senior Consultant role Experience designing and delivering scalable systems Strong stakeholder management ...

Hybrid - 3 days in office) Sector: Technology Transformation Type: Permanent The Role We are seeking an experienced Technical Architect to lead the planning, design, and implementation of Python-based applications. You will ensure projects are completed on time and within scope while coordinating between cross-functional teams to align … technical delivery with business goals. Your Responsibilities Architectural Leadership: Lead the design of complex Python applications, focusing on scalability, performance, and maintainability. Framework Selection: Evaluate and select appropriate frameworks (Django, Flask, FastAPI) based on specific project needs. Technical Documentation: Create detailed design documents, including system diagrams, data flow ...

across UK government departments. Our work has positively influenced the lives of over 40 million UK citizens. With a strong commitment to user-centred design and agile delivery, and more to deliver innovative digital services that matter. Role Description As a Lead Software Engineer, you will provide technical leadership … across the development and enhancement of the digital services. You will design and oversee secure, scalable application architectures within Google Cloud Platform, ensuring alignment with GDS standards and public sector governance. You will lead development across Python-based services, APIs and web applications, ensuring integration with data platforms ...