76 to 100 of 104 API Design Jobs in London

development. As the Head of Software Architecture you will collaborate with Team Leads across the business to support them with technical architecture and design on large, complex, cloud based distributed systems, ensuring best practice and a cohesive structure. The tech stack is based on modern Java and AWS, using … agentic AI development tools and how to implement them and drive change within the business You have a strong knowledge of microservices architecture, API design, enterprise integration patterns, AWS cloud architecture You have a good understanding of modern software development practices e.g. TDD, CI/CD, DevOps, SecOps ...

cloud platforms is beneficial but not essential) Strong collaboration and communication skills 4+ years of experience in data-focused software development, including data modelling, design patterns, and building scalable, secure systems Working knowledge of software engineering principles and best practices, including testing, packaging, API design, DevOps, DataOps ...

high standards for security, auditability, and compliance Main Skills Needed: Strong background in building and running production-grade systems Solid backend engineering expertise and API design experience Good understanding of relational databases and data modelling Experience working in regulated or audit-heavy environments Full stack capability across frontend ...

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 ...

working hours, patterns and locations to suit you and our business. About the Opportunity As a Principal Solutions Architect, you will specialise in the design, development and governance of integrated digital project controls environments across major capital programmes. This is not a general IT solutions architecture role. … needed. Key Responsibilities Define enterprise aligned solution architectures for programme controls platforms covering cost, schedule, risk, performance reporting and data governance. Lead evaluation, selection, design and configuration of programme controls systems such as EcoSys, Oracle Primavera P6 and Unifier, Aconex, CDEs including SharePoint and ProjectWise, and related digital delivery ...

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. ...

develop new features, enhance existing systems, and ensure our platform remains stable and efficient. Your deep understanding of Rails architecture, PostgreSQL optimisation, and API design will be essential as you contribute to ongoing development projects. If you enjoy collaborating in Agile/Scrum environments, value clean code ...

worlds leading banks in their high-performing engineering teams, building asynchronous, message-driven systems designed for scale, resilience, and near-zero downtime. Design and implement high-throughput, low-latency systems processing millions of real-time payment events Build event-driven architectures using modern Java and reactive frameworks Work extensively … with non-blocking I/O, asynchronous flows, back-pressure, and concurrency Contribute to system and API design, focusing on scalability, fault tolerance, and observability Collaborate closely with architects, engineers, and client teams across Europe Operate in Agile environments (Scrum/Kanban) with a strong engineering culture Tech ...

stuck into some genuinely interesting engineering. Think computational complexity, mathematical optimisation, and performance challenges at scale - a long way from your average API job. Requirements: 7+ years experience developing and maintain scalable Python/FastAPI back-end services Ideally worked with high-performance APIs for complex hierarchical data queries … code Lead technical planning by breaking down roadmap items into scoped engineering work, driving ADRs and setting standards for code quality, testing, and API design Collaborate cross-functionally with front-end, data engineering, modelling and product teams to deliver reliable, impactful features Line-manage a team ...

stuck into some genuinely interesting engineering. Think computational complexity, mathematical optimisation, and performance challenges at scale - a long way from your average API job. ⚡ Requirements: 7+ years experience developing and maintain scalable Python/FastAPI back-end services Ideally worked with high-performance APIs for complex hierarchical data queries … code Lead technical planning by breaking down roadmap items into scoped engineering work, driving ADRs and setting standards for code quality, testing, and API design Collaborate cross-functionally with front-end, data engineering, modelling and product teams to deliver reliable, impactful features Line-manage a team ...

All3 is transforming how buildings are conceived, developed, and delivered. We combine AI-powered design with robotic prefabrication and on-site assembly to build custom architecture at the cost and speed of mass production - unlocking even the most complex sites. We’re currently seeking a Principal Platform Software Engineer … trade-offs to meet business goals; Leading technical discussions across robotics, hardware, controls, and product teams; Applying systems engineering principles to requirements analysis, architecture design, verification, and validation. Expertise: Expert-level experience in production-grade software development with Modern C++ and Python; Strong experience working in embedded Linux environments ...

Sector: Defence & National Security Role Summary Our client is seeking DV cleared Backend Developers to support high impact Defence and Security programmes. You will design, build and operate secure, cloud-native backend services that underpin mission-critical national systems. This is a hands on engineering role, focused on building … will work end to end - from shaping technical designs and delivering features through to improving reliability, resilience and performance in live operations. Key Responsibilities Design and build backend services and APIs, delivering features end-to-end in collaboration with cross-functional teams. Develop cloud-native and containerised applications using ...

Technical Skills Required Data Tools: SQL, Python, Snowflake/Databricks, Tableau/Power BI. Frameworks: Agile/Scrum, MLOps, Data Governance, Metadata Management. Integration: API design, event-driven architecture, and data modeling. Randstad Technologies is acting as an Employment Business in relation to this vacancy. ...

joining a small team building cto.new and shaping how it gets built. What we care about: Strong TypeScript and solid backend fundamentals - data modeling, API design, concurrency, failure modes Production experience with LLM features - tool-calling, prompt iteration, streaming, evals, cost and latency tuning AI-native workflow - fluent ...

evolution of core Ruby on Rails operational platforms. Optimise PostgreSQL performance and Sidekiq background job efficiency. Manage secure third-party integrations and RESTful API design. Partner with Platform teams on AWS and CI/CD reliability. The Person: Deep experience with Ruby on Rails and OOP. Expert in PostgreSQL ...

influence architectural decisions at a critical stage of growth. The 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 to 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 data ...

complex risk calculations and high-throughput financial data processing. This is an environment where your technical expertise in Object-Oriented Programming (OOP) and API design will directly impact global operations and regulatory compliance. Key Responsibilities Engineering: Build scalable, testable, and maintainable applications using .NET Core and RESTful APIs … systems. Collaboration: Work alongside Quants, Risk Managers, and Front Office teams to translate business needs into technical reality. Architecture: Participate in high-level technical design and architectural discussions to evolve the platform. Requirements Technical Core: Extensive experience in C#, .NET, SQL Server, and CI/CD pipelines. Domain Expertise ...

Expert Developer: Java experience (Spring Boot, Bazel, Maven) with a focus on distributed services and Kubernetes (GKE). System Designer: Strong skills in API design (gRPC, GraphQL, REST) and relational databases like PostgreSQL. Cloud Proficient: Hands-on experience with GCP services, including BigQuery and Cloud SQL. Security Minded ...

systems in production and 3–5 years of substantive software/platform engineering Deep JavaScript/Node.js skills Azure Fluency JSON data structures, REST API design, and complex semi-structured data Practical LLM application — RAG architectures, prompt engineering etc Comfort with both relational (MS SQL) and document (MongoDB ...

Acting as a senior technical authority, championing Wilmington s composable, microservice-based platform strategy and making sound architectural decisions on integration approaches and system design • Proactively identifying and mitigating technical risks and support the CTO with technical due diligence for future acquisitions • Operating across multiple scrum teams, bridging project … architecture experience, providing the credibility to confidently interrogate system designs, integration strategies, and technical trade-offs • Strong expertise in composable, microservice-based architectures, including API design, event-driven integration, and service decomposition • Proven track record delivering large-scale platform integration or migration programmes across complex, multi-system ...

Acting as a senior technical authority, championing Wilmington’s composable, microservice-based platform strategy and making sound architectural decisions on integration approaches and system design • Proactively identifying and mitigating technical risks and support the CTO with technical due diligence for future acquisitions • Operating across multiple scrum teams, bridging project … architecture experience, providing the credibility to confidently interrogate system designs, integration strategies, and technical trade-offs • Strong expertise in composable, microservice-based architectures, including API design, event-driven integration, and service decomposition • Proven track record delivering large-scale platform integration or migration programmes across complex, multi-system ...

engineers across the organisation What you'll need to succeed 8+ years' experience in software engineering, with strong fundamentals in distributed systems and system design Proven background building and operating large-scale backend platforms in production Experience working within a product-led environment Hands-on experience with cloud-native … technologies, containers, and CI/CD pipelines Experience influencing technical direction across teams or domains Strong expertise in: Java Distributed systems architecture API design Performance optimisation and scalability Nice to have: Previous experience at Staff/Principal/Tech Lead level Exposure to high-volume, low-latency data ...

that supports business critical functions across the business. My client have migrated significant services to the cloud and now requires a lead architect to design and build the next generation of solutions including core finance and HR technology landscape, automating data flows, integrating systems, supporting in the delivery … real-time reporting and analysis, whilst driving a more mature awareness to data architecture and governance across the business. Responsibilities: - Lead the design and delivery of integrations across technology platforms and solutions. - Produce architectural documentation (HLDs, LLDs, diagrams, support guides). - Ownership of integration and application architecture in alignment ...

share code with iOS. You’ll be joining a collaborative engineering group working on major new features, shaping technical discussions, influencing architecture and API design, and helping to evolve a category-defining product used across the UK, US and several new international markets launching in 2026. What they ...

team. You’ll be interfacing with the business regularly, so strong communication skills are important. Ideal person is tech first (Strong Python engineering fundamentals, API design) while getting exposure to modern tech across the stack such as UI's, messaging frameworks and data validation tools. Having the experience ...