6 of 6 Contract API Design Jobs in London

Senior API Technical Consultant (GraphQL Specialist) Design and build next generation of high-scale SaaS platforms. We're looking for a senior/lead engineering consultant with deep expertise in GraphQL to take a leading role in developing our robust TypeScript/Node.js backend. You will be instrumental in shaping our technical direction, driving the evolution of our … APIs, ensuring our services are resilient, scalable and secure within a cutting-edge, cloud-native environment (Helm, Kubernetes). The Deliverables Design and build sophisticated, scalable GraphQL APIs and backend services using TypeScript and Node.js. Lead the design and evolution of our API schemas, ensuring they meet the complex demands of a rapidly growing platform. Champion best … team to guide process improvements and make key architectural decisions. Experience Extensive production experience architecting and delivering complex applications with TypeScript and Node.js . Expert level GraphQL , including advanced API design, schema evolution, performance optimisation. Strong automated testing frameworks like Vitest and Playwright . Proficiency with modern DevOps tooling and cloud-native architecture, including Docker , Helm , Kubernetes . More ❯

the technical direction for our development teams. This role bridges development and operations while ensuring secure, scalable, and resilient systems. The ideal candidate will have deep experience in AWS, API management, infrastructure automation, and secure software development practices, combined with the ability to guide teams on security posture, vulnerability management, and compliance alignment. Key role and responsibilities Architecture & Technical … standards with a focus on security, resilience, and scalability. Provide technical direction and mentorship to development and DevOps teams. Drive adoption of secure coding practices, threat modelling, and resilient design patterns. Security & Compliance Implement and maintain security best practices across CI/CD pipelines and infrastructure. Lead vulnerability management, including scanning, remediation, and dependency upgrades. Ensure API security … using OAuth, JWT, API keys, and other mechanisms. Collaborate with InfoSec teams to align with organizational compliance frameworks. Platform Maintenance & Resilience Oversee regular upgrades of libraries, packages, and infrastructure components. Establish disaster recovery strategies, high availability configurations, and resilience testing. Automate upgrade workflows using Infrastructure-as-Code and CI/CD tools. Infrastructure & DevOps Design and manage secure More ❯

transformation programme, and are looking for an experienced Integration Architect to join on a 12-month contract . This role is ideal for someone who specialises in system integration, API design, and cloud-based architecture (Azure) and enjoys shaping strategy as well as guiding delivery teams. Key Responsibilities Define and deliver the integration architecture strategy for a group … wide transformation. Design and govern API-led integrations, interface specifications, message schemas, and data flows. Work closely with Solution Architects, Cloud Architects, Product Owners and delivery teams to ensure scalable, secure and future-proof integration solutions. Champion integration best practices, standardisation and reusability across programmes. Provide technical leadership, documentation, and mentorship to delivery teams. Ensure all integration solutions … data protection standards. What We're Looking For Proven experience as an Integration Architect/Solution Architect with strong integration focus Hands-on knowledge of Microsoft Azure integration services (API Management, Service Bus, Logic Apps, Event Grid, etc.) Strong understanding of enterprise integration patterns, API management platforms (Apigee/Azure API Mgmt) Experience working in agile delivery More ❯

every year of education • At least 8-10 years of experience with Information Technology Key Responsibilities • Develop and maintain enterprise-scale .NET applications using ASP.NET Core 9.0 and C# • Design and implement RESTful APIs for biogas trading, inventory management, and regulatory reporting • Build complex business logic for RINS credit calculations, LCFS compliance, and carbon credit trading • Work with PostgreSQL … and Microsoft Identity Platform • Develop email workflow systems and automated reporting for regulatory compliance • Create scheduled background jobs using Quartz.NET for data processing and calculations • Integrate with Microsoft Graph API for SharePoint document management via Azure MS Graph • Build real-time features using SignalR for live trading updates • Implement data validation using FluentValidation • Work with Docker and OpenShift for … containerized deployments Required Technical Skills • 5+ years of experience with .NET development (C#, ASP.NET Core) • Strong experience with Entity Framework Core and PostgreSQL • Proficiency in RESTful API design and OpenAPI/Swagger documentation • Experience with authentication systems (OAuth2, JWT, Azure AD) • Knowledge of containerization (Docker) and Kubernetes/OpenShift • Experience with background job processing and scheduled tasks • Understanding More ❯

based applications that leverage generative AI capabilities. This hands-on position requires deep technical expertise to translate business needs into robust, scalable, and intelligent software solutions. Your responsibilities: Software Design & Development: Design, develop, and maintain high-quality, scalable, and efficient software applications and services. Write clean, well-documented, and maintainable code following established best practices. Translate complex business … requirements into detailed technical specifications, architectural designs, and API contracts. Create and implement microservice architectures via APIs and services, ensuring seamless integration and data flow. GenAI Application Development: Develop and integrate advanced Generative AI models and Agentic AI approaches into new and existing applications. Optimize application code and architecture for performance, scalability, security, and cost-effectiveness. Work with data … engineers, to deliver features iteratively. Participate actively in agile ceremonies (e.g., stand-ups, sprint planning, retrospectives). Create and maintain comprehensive technical documentation, including code documentation, system designs, and API specifications. Security & Compliance (Application Layer): Ensure all software solutions adhere to secure coding practices, data privacy regulations, and compliance standards. Implement robust security measures within the application code, including More ❯

and Spring Boot experience, solid understanding of Kubernetes and AWS services, and hands-on database development with SQL-based systems. Familiarity with mobile integrations (iOS/Android native), RESTful API design, and Agile delivery methodologies will be highly beneficial. This is an exciting opportunity to work in a dynamic FinTech environment where innovation, quality, and performance are at More ❯