1 to 25 of 28 Permanent API Design Jobs in Central London

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 ...

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 ...

seeking a Senior Java Developer to join a modern engineering team building high-performance, cloud-native services. You will take ownership of backend design and delivery, mentor engineers, and help elevate engineering standards. A key focus of this role is accelerating team capability with GitHub Copilot —we are looking … genuine enthusiast who uses it daily, understands the newest features, and can coach others to use it safely and effectively. Key Responsibilities Design, build, and optimise microservices and APIs using Java 21 . Drive best practice in code quality, testing, secure coding, and performance tuning. Build and integrate with ...

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 ...

pure DevOps role. You will spend significant time on platform engineering, CI/CD, and infrastructure – but you will also contribute to application development, API design, and integration work. We need a generalist who leans platform, not an infrastructure specialist who only touches pipelines. What … fast diagnosis and recovery. • Define and track availability and reliability targets; drive post-incident review and preventative improvements. Application Development • Contribute to backend development: API endpoints, service logic, database schema, and integration code. This is a building role, not only an operations role. • Design and implement integration patterns ...

people actually love to use? We are representing a globally recognized digital product studio that sits at the sweet spot of high-end aesthetic design and hardcore engineering. They're looking for a Senior & Lead Full-stack Engineer to join the growing function. This isn't a "ticket-taking … robust, scalable backend. What You Bring to the Table React Node/TypeScript/JavaScript Cloud: AWS, Azure, or GCP. APIs: API design and integration (REST & GraphQL). Databases: SQL, NoSQL, real-time, etc. AI Tooling: Confident using AI-boosted environments to ensure quality (Claude or similar). ...

development tools across your team Foster culture of learning, experimentation, and knowledge sharing Work with Head of Engineering on architecture, partner with product and design teams About You You're a strong senior engineer ready to lead a team but who still loves writing code. You have solid technical … Strong expertise in Python backend development with async patterns Production experience with modern frontend frameworks (React, TypeScript) Solid understanding of distributed systems architecture and API design Experience with container orchestration, CI/CD, and cloud platforms Experience with NoSQL databases and data modelling Daily user of AI-assisted ...

Computer Science, Mathematics, Software Engineering, Physics, and Data Science. You write and review production-grade Python and SQL, and have strong command of REST API design and integrations. You excel at breaking down complex problems and making quick, well-informed decisions even under pressure. You build strong relationships ...

agility with the backing of a well-established business. The Senior Back End Developer will... take ownership of backend engineering for a new API-first data intelligence platform. Role Highlights Design and build scalable backend systems from a true greenfield starting point Define architecture, balancing rapid delivery with … long-term scalability Develop API-first services for data-heavy, enterprise-grade applications Embed observability, metrics, and performance tracking from day one Collaborate within a small, high-autonomy team shaping a new product You Will Need Extensive backend development experience within data-driven B2B environments Strong programming skills ...

maintain server-side logic using modern backend frameworks (e.g. Node.js, Python, Go) Work with APIs — designing, integrating, and maintaining RESTful endpoints Support database design and optimisation (e.g. PostgreSQL, MongoDB) Collaborate with front-end and product teams to deliver full-stack features Write clean, testable, and maintainable code Help improve ...

create the world’s leading, commercially scalable, safe, and advanced humanoid robots that seamlessly integrate into daily life and amplify human capacity. Responsibilities Design and implement a centralized cloud-based platform for managing a fleet of humanoid robots, monitoring system health, and visualizing fleet-level KPIs Develop robust backend … Expertise Proficiency in one of Python, Javascript, Golang or Rust Familiarity with React (or similar frameworks) for creating user-friendly web applications. Expertise in API design, data modeling, and distributed architectures Proficiency with CI/CD pipelines, containerization (e.g., Docker, Kubernetes), and workflow automation. Proficiency in infrastructure ...

Experience working on the engineering team in a start-up, scale-up or product-driven company Strong understanding and experience with building and consuming API-driven solutions. Experience with database technologies, cloud platforms (e.g., AWS, Azure, GCP), and API design principles. A minimum of a Bachelor ...

+ mobile applications Building and maintaining high‐performance APIs and distributed microservices Solving problems around scalability, reliability, security, and automation Working with modern API protocols including GraphQL and gRPC Enhancing the platform that connects both traditional and on‐chain financial services Must‐have experience: Strong backend engineering background with …/or Golang Solid understanding of microservices, event‐driven systems & distributed architecture Strong knowledge of PostgreSQL and/or Redis Understanding of web semantics, API design & backend web standards Proficiency with Git and version control workflows Experience with CI/CD, build automation and modern engineering pipelines Excellent ...

architecture Extensive experience with PostgreSQL, including performance tuning and complex queries. Experience with background job processing using Sidekiq and Redis. Solid understanding of RESTful API design, JSON serialization, and authentication (e.g., JWT, SSO). Hands-on experience with AWS services and containerised deployments (Docker). Experience troubleshooting ...

full-stack product delivery, from infrastructure and AI integrations through to React/React Native interfaces, collaborating closely with founders, creators, product, and design to turn lean specs into scalable, user-loved software. We’re looking for a strong generalist with backend depth and real mobile experience. Responsibilities Implement … mobile + web frontend → APIs → data models → integrations) while maintaining quality and velocity. Build React Native mobile apps and shared component systems across products. Design and ship scalable backend services (APIs, integrations, AI workflows). Run tight build → test → iterate → ship loops; provide realistic estimates and surface blockers early. ...

seasoned technical leaders. What matters is how you think, build, and ship. You'll take end-to-end ownership of features from architecture design to measurable impact — shipping code that directly moves revenue, retention, or product velocity. You'll design clean abstractions in ambiguous environments, evolve systems into … . We care about outcomes, not activity. What We're Looking For You've built and shipped real systems. You understand data modelling, API design, system trade-offs, testing, and reliability. You know how to move fast without creating chaos. You're strong in at least one modern ...

Start Up - Smart Living Platform Fully Remote - Must be UK based £85,000 - £95,000 + Stock Options (DOE) Essential Exp: Laravel, Flutter, SaaS, API Design, MySQL/PostgreSQL/MariaDB G.R.E. Recruitment is DELIGHTED and EXCITED to partner with an exciting UK based PropTech Start-Up company … defining technical standards, scalability strategy, and product direction across the technical ecosystem. In this role you will: Own and evolve a Laravel-based REST API Develop and maintain a Flutter mobile application (iOS & Android) Design and implement secure, multi-tenant architecture Establish clean coding standards and engineering best ...

architectural direction, influencing engineering standards, and shaping the evolution of AI-enabled capabilities across the mobile platform. In this role, you will: Lead the design, development, and maintenance of advanced iOS applications, ensuring high performance, quality, and responsiveness across Expedia Group’s product suite. Architect and implement robust, scalable … system and API designs, including effective data modelling to support complex business requirements. Drive cross-functional collaboration to define, develop, and ship impactful features, ensuring alignment with organisational goals and technical strategy. Champion best practices in software engineering, testability, and maintainability through code reviews and mentoring. Safely integrate ...

ensuring solutions are secure, scalable and aligned with the organisation's long-term technology strategy. Key Responsibilities Define and govern technical architecture standards and design principles Provide hands-on architectural leadership across cloud platforms, integrations and development Lead architecture reviews and technical design decisions Support engineering teams with … Senior Developer Strong experience with Microsoft Azure cloud platforms Experience working with Dynamics 365/CRM environments Knowledge of cloud architecture, integrations and API design Familiarity with DevOps and modern engineering practices Strong communication skills and ability to engage both technical and non-technical stakeholders Benefits Salary ...

edge AI functionality across a flagship cybersecurity platform, building scalable, performant systems that harness the power of data, ML models, and infrastructure. Key Responsibilities: Design, develop, and deploy production-grade ML/AI features — from data prep and model training to inference APIs and monitoring. Integrate and scale LLMs … PyTorch and scikit-learn . Hands-on experience with state-of-the-art foundation models, embeddings, and RAG. Strong knowledge of cloud computing, microservices, API design, and event-driven architectures. Experience with Jupyter notebooks for data exploration and model iteration. About You: You are driven, empathetic, and thrive ...

platform used by clients, operations teams and field contractors across the UK. You will work across Python and Django on the backend, contributing to API design, system architecture and end to end feature delivery. The environment includes modern web technologies such as React and HTMX, supported ...

influence architectural decisions at a critical stage of growth. The Senior Backend Engineer (Full Stack, backend-leaning) will take ownership of complex backend REST API Services and deliver scalable systems using TypeScript and Node.js . You will closely with Product, Engineering and Operations, working alongside the Lead Engineer … refine technical direction, improve delivery standards and elevate system reliability. The Senior Backend Engineer (Full Stack, backend-leaning) will... • Design and maintain scalable Node.js/TypeScript services and REST APIs • Own backend initiatives end-to-end, from architecture to rollout • Strengthen testing strategy across unit and integration layers • Improve ...

commercial software development experience. Proven success in high-performing engineering teams within fast-paced environments. Deep expertise in: Python (Django, Flask, or FastAPI) PostgreSQL (design, optimisation, maintenance) Containerisation (Docker/Kubernetes) Event-driven architecture (Kafka/RabbitMQ) Desirable experience includes: TypeScript/JavaScript (NextJS, NodeJS, Tailwind) Terraform and DevOps … practices Experience in building and scaling SaaS platforms in production. Strong background in software architecture, microservices, and API design. Hands-on experience with AWS platform. Excellent communication skills, capable of motivating and aligning technical teams. Experience with AI tools, APIs, or ML pipelines is highly desirable. Bonus: Exposure ...

operations teams and field contractors across the UK. You will work on modern web applications using Python, Django, HTML, HTMX and React, contributing to API design, system architecture and end to end feature delivery. This is a high ownership role suited to someone comfortable working autonomously ...