51 to 75 of 198 API Design Jobs in the UK

Principal Technology Architect - LLMs, agentic coding systems, intelligent IDEs, AI

Hiring Organisation
Jobleads-UK
Location
Greater London, England, United Kingdom
Required Technology 15+ years of progressive software engineering; 5+ years leading AI‐native solutions at enterprise scale. Hands‐on with LLMs and agentic frameworks; design and deploy AI systems that augment SDLC (requirements → coding → testing → ops). Tooling & Platforms (practitioner proficiency) Claude Code (Anthropic) for secure, context‐rich code …/Gemini for research workflows where permitted; govern enterprise knowledge ingestion. Architecture & Integration Distributed systems, microservices, cloud‐native (Azure/AWS/GCP); secure API design (REST/GraphQL). MLOps & AIOps: CI/CD for AI, model lifecycle (eval, versioning, rollout/rollback), guardrails, telemetry, drift monitoring ...

Backend Engineer

Hiring Organisation
Robert Half Limited
Location
London, United Kingdom
Employment Type
Contract, Work From Home
systems that enable global commerce, while evolving an existing real-time platform to support new markets. You will address backend capacity constraints and help design a shared transaction and ledger layer used across multiple business lines. This is a hands-on senior engineering role requiring both high-quality delivery … strong technical leadership in ambiguous, high-scale environments. You will be expected to: Design scalable systems with correctness and failure modes considered from the outset Clarify and scope requirements before proposing solutions Make pragmatic trade-offs in system design, avoiding over-engineering Operate independently without reliance ...

Senior Tech Lead, Enterprise AI Products (Contract)

Hiring Organisation
Harnham - Data & Analytics Recruitment
Location
London, South East, England, United Kingdom
Employment Type
Contractor
Contract Rate
£700 - £800 per day
deliver against them. It is not a programme, delivery or governance position: you make the architectural calls rather than facilitate them. You will: Design large-scale agentic AI architectures: LLM document processing, structured extraction, RAG, invoice-to-contract matching Own low-level design decisions, including API design ...

Technical Lead - Java

Hiring Organisation
Sanderson Recruitment
Location
London, United Kingdom
Employment Type
Permanent
Salary
£95,000
helping shape modern platforms that leverage Agentic AI, workflow orchestration, and intelligent automation to solve complex business challenges. What You'll Do Lead the design and delivery of scalable Java 17+/Spring Boot microservices Own architecture decisions, system design, and engineering standards Design resilient, high-performance … adoption of AI engineering tools including GitHub Copilot, Cursor, and Claude Code Deliver AI-powered features using LLMs, RAG, semantic search, and intelligent automation Design workflow orchestration solutions using Camunda or similar BPM platforms Lead the implementation of Agentic AI capabilities, autonomous workflows, and AI-driven decision making Drive ...

Senior Software Engineer – Payment Capabilities

Hiring Organisation
Jobleads-UK
Location
Greater London, England, United Kingdom
Design, build, and evolve payment services and capabilities that enable seamless customer transactions across M&S digital platforms. Develop resilient backend services, APIs, and integrations that support millions of customer payment journeys every year. Own features end-to-end, taking responsibility for solution design, development, testing, deployment … testing, and maintainability. Proficient in driving operational excellence through observability and modern engineering practices. Highest-signal resume keywords Java Engineering Expertise Backend Service Development API Design and Integration CI/CD Implementation Observability and Monitoring Hard Skills Backend Development API Development System Design Scalable Systems Resilient ...

Senior Software Engineer

Hiring Organisation
Fruition Group
Location
City of London, London, United Kingdom
Employment Type
Permanent
Salary
£90,000
where correctness, transparency and performance matter. You'll have real ownership, from architecture through deployment, across new and existing products. What You'll Do Design, build and ship features across the full stack (Fastify microservices, React/MUI, shared TypeScript packages in a pnpm monorepo) Design and evolve … backend services for high-volume, distributed screening workloads Build event-driven pipelines (AWS SNS/SQS) with idempotent consumers, DLQs and batch processing Design clean APIs and contribute to architecture across multiple products Integrate external identity, KYC and payments platforms (e.g. Senzing, Auth0, Stripe) Own services ...

Principal Developer

Hiring Organisation
Jobleads-UK
Location
Greater London, England, United Kingdom
delivery methodology to ensure timely and high-quality delivery of software applications. Technical Ownership: Take technical ownership of a product or software solution, covering design, estimation, shaping, and user story/requirement creation. Solution Documentation: Document solutions, including architecture, configuration, release, and support handover. Stakeholder Collaboration: Collaborate and liaise … practices and modern architectural patterns, including microservices and message-driven architectures. Non-Functional Requirements: Experience developing applications with non-functional requirements in mind. Application Design: Experience in application/digital services design. Software Engineering Practices: Proficiency in software engineering practices like code reviews, CI/CD pipelines, and SOLID ...

Java Developer - Government Experience Needed

Hiring Organisation
Stealth IT Consulting Limited
Location
United Kingdom
Employment Type
Contract
Contract Rate
£400 per day 400 Inside IR35
Title: Java Developer Rate: £400 (Inside IR35) Duration: 12 Months Location: Remote Clearance: BPSS Stages: 1 Stage Must Have Government Experience Key Responsibilities Design and develop high-quality Java applications and microservices. Build and maintain RESTful APIs and Back End services. Collaborate with architects, business analysts, testers, and DevOps … engineers. Contribute to technical design discussions and architectural decisions. Implement automated testing and support a TDD approach. Participate in code reviews and promote engineering best practices. Develop and deploy applications using cloud-native technologies. Troubleshoot and resolve production issues. Ensure solutions meet security, performance, and accessibility requirements. Essential Skills ...

Developer Enablement, Technical Architect – Release on Demand (SVP)

Hiring Organisation
Jobleads-UK
Location
Greater London, England, United Kingdom
built to last and built to scale.* **Drive Scalability & Reliability.** Lead the engineering effort to make RoD elastically scalable and enterprise-grade reliable. Design for high availability, graceful degradation, and zero-downtime deployments. Define SLOs, own the SRE practice for the platform, and be accountable when things need fixing. … fully understood at all times. You will set the standard and ensure the team can operate with confidence.* **Establish End-to-End Testing.** Design and champion a robust E2E testing strategy across the platform. From contract testing at service boundaries to full integration and regression suites, you will ensure ...

Solutions Architect

Hiring Organisation
Euro Car Parks
Location
Central London, London, United Kingdom
Employment Type
Permanent
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 ...

Senior .Net Developer

Hiring Organisation
Ascend Consulting
Location
Mill Hill, Dumfriesshire, United Kingdom
Employment Type
Permanent
Salary
GBP 50,000 - 85,000 Annual
Senior .Net Developer, C#/VB.Net, API, SQL, NW London to £85K A Back End Developer is required to join this established financial software house based in North London. They work with some of the leading brands in retail and media, offering financial management systems developed in house … required with expertise in Visual Basic .NET, C#, SQL Server, and SAP Business One integration. The ideal candidate should have strong skills in RESTful API development, database optimization, and Azure DevOps pipeline management. Knowledge of API security, CI/CD automation, and Swagger documentation is recommended. Responsibilities API ...

Senior .Net Developer

Hiring Organisation
Ascend Consulting
Location
NW7, Mill Hill, Greater London, United Kingdom
Employment Type
Permanent
Salary
£50000 - £85000/annum
Senior .Net Developer, C#/VB.Net, API, SQL, NW London to £85K A Back End Developer is required to join this established financial software house based in North London. They work with some of the leading brands in retail and media, offering financial management systems developed in house … required with expertise in Visual Basic .NET, C#, SQL Server, and SAP Business One integration. The ideal candidate should have strong skills in RESTful API development, database optimization, and Azure DevOps pipeline management. Knowledge of API security, CI/CD automation, and Swagger documentation is recommended. Responsibilities API ...

Java Developer

Hiring Organisation
Capgemini
Location
Manchester, United Kingdom
Employment Type
Full Time
Tomorrow., you will help deliver high-quality, business-critical solutions that create measurable client outcomes. Working alongside multidisciplinary teams, you will contribute to the design, development, and evolution of scalable applications, while embracing innovation, continuous improvement, and AI-enabled ways of working. This role is ideal for individuals … unable to work at home 100% of the time. Your Role: Deliver scalable, secure, and resilient application solutions that meet client and business objectives. Design, develop, and maintain high-quality backend services and reusable components. Contribute to the successful delivery of distributed and service-oriented solutions that enable business ...

Python Developer

Hiring Organisation
Spencer Rose Ltd
Location
Watford, Hertfordshire, United Kingdom
Employment Type
Permanent
Salary
GBP 70,000 - 75,000 Annual
occasional out-of-hours support. Ensure unit tests are implemented and fit for purpose. Research and evaluate new technologies that could benefit the organisation. Design and develop high-quality Python software that meets complex business needs. Ensure code, documentation, and testing align with engineering standards. Deliver solutions that meet … expectations, and operational reliability. Integrate products with monitoring and support tooling. Experience/Skills required: Experienced Python Developer who can make sound trade-offs, design for scale, and contribute to complex systems without over-engineering. Strong engineering judgement and real-world delivery experience. Senior-level experience designing and building ...

Product Management - Private markets, Charles River Development, Assistant Vice President

Hiring Organisation
Jobleads-UK
Location
Greater London, England, United Kingdom
deliver the roadmap for horizontal platform capabilities serving all private markets asset classes - including core data services, cross-fund analytics, workflow automation, and API infrastructure. Lead initiatives in AI/ML-enabled product features, including document extraction (e.g., fund documents, LP agreements, investment memos), NLP-powered search, and intelligent … reporting cycles. Demonstrated experience owning platform-level or infrastructure product workstreams with high technical complexity. Familiarity with data architecture concepts: data modeling, ETL pipelines, API design, and event-driven systems. Experience with agile development methodologies; strong proficiency with product management tools (Jira, Confluence, Productboard, or similar). Exceptional ...

Developer

Hiring Organisation
Parity Network
Location
Edinburgh, City of Edinburgh, United Kingdom
Employment Type
Contract
Contract Rate
£475/day
across Scotland. The Role You'll play a key role in developing and supporting modern digital services, working within high-performing Agile teams to design, build and enhance secure, resilient and user-focused applications. Key responsibilities include: Developing and supporting modern software solutions using Java, Spring Boot and React. … pipelines and cloud-native deployments. Designing and implementing scalable technical solutions aligned to Digital First and GDS standards. Building reusable UI components and maintaining design systems. Developing automated testing using TDD, Playwright and Consumer-Driven Contract Testing. Troubleshooting issues across cloud-native platforms and legacy environments. Participating in code ...

Senior Engineer

Hiring Organisation
Jobleads-UK
Location
Greater London, England, United Kingdom
services effectively. The role will be working closely alongside the SPM business team and technology vendors to engineer solutions supporting their strategic roadmap. Responsibilities: Design, build, and improve modern application services that support a strategic business platform, focusing on quality, maintainability, and performance. Develop backend services and APIs supporting … strong track record of delivering production systems. Strong experience building backend applications and APIs, ideally in Java. Practical experience across service‐based architecture, API design, integration patterns, and modern web application delivery. Experience contributing to modernisation or platform evolution initiatives is strongly desirable. Strong engineering discipline across testing ...

Senior Cloud Software Engineer

Hiring Organisation
Jobleads-UK
Location
Cambridge, England, United Kingdom
Title: Senior Cloud Software Engineer Location: Cambridge, UK - Hybrid Employment Type: Full-time Key Responsibilities Design, develop, and maintain secure, resilient features for AVEVA CONNECT Core Services Contribute to technical design and implementation decisions across cloud and service-based architectures Build and improve services using modern engineering practices … engineering productivity, code quality, and delivery Work collaboratively in an agile development team and share knowledge on cloud technologies and practices Essential Requirements Strong design and coding skills, with a record of delivering high-quality technical outcomes Experience developing microservice or service-oriented architectures Good understanding of REST API ...

AI Platform/ DevOps Engineer

Hiring Organisation
The Portfolio Group
Location
City of London, London, Castle Baynard, United Kingdom
Employment Type
Permanent
Salary
£70000 - £100000/annum + Benefits
secure, and cost-efficient platform infrastructure that enables AI engineering teams to ship and operate AI products reliably in production. What you'll do Design, build, and operate cloud-native AI platform infrastructure across AWS (Lambda, API Gateway, DynamoDB, S3, CloudWatch) and Databricks Deploy and operate containerised services … workflows, and RAG components Implement observability across AI workloads using CloudWatch, MLflow, and OpenTelemetry - covering latency, throughput, cost, and system health Apply secure-by-design principles including IAM, encryption, network controls, and audit logging Work closely with AI engineers to translate prototypes and proof-of-concepts into production-ready ...

Python Software Engineer

Hiring Organisation
Spencer Rose Ltd
Location
Watford, Hertfordshire, UK
Employment Type
Full-time
hours support. \n Ensure unit tests are implemented and fit for purpose. \n Research and evaluate new technologies that could benefit the organisation. \n Design and develop high-quality Python software that meets complex business needs. \n Ensure code, documentation, and testing align with engineering standards. \n Deliver solutions … Integrate products with monitoring and support tooling. \n\n Experience/Skills required: \n \n Experienced Python Engineer who can make sound trade-offs, design for scale, and contribute to complex systems without over-engineering. \n Strong engineering judgement and real-world delivery experience. \n Senior-level experience designing ...

VP & Staff Software Engineer(s)

Hiring Organisation
Jobleads-UK
Location
Greater London, England, United Kingdom
work: billing, payments, subscriber management, RADIUS‐based network authentication, and integrations with ISP billing systems and mobile money providers. We are replacing legacy, non‐API systems with a modern API platform, and real money is already flowing through the system. This is a small, high‐intensity engineering team … when they hit technical walls. You will not manage people. You will build systems. What you will own Payments domain: SasaPay collections integration (C2B API, STK push, IPN handling), revenue split engine (per‐partner, per‐BNG percentage logic), ChoiceBank treasury operations (withdrawals, internal transfers, OTP flows), and the payment ...

Cloud Engineer

Hiring Organisation
BAE Systems
Location
City and Borough of Leeds, United Kingdom
Employment Type
Full Time
core mission capabilities. You’ll work as part of empowered, autonomous DevOps teams with regular contact with end-users to flexibly and efficiently understand, design, develop, deploy and maintain applications and services on AWS. You’ll be encouraged to identify new ways of solving problems and get to work … help you with them AWS Certification at Associate level eg Solution Architect, Developer or DevOps Expertise in microservices and API design Docker, and container runtime platforms such as Kubernetes, EKS, ECS etc Strong understand of operational concepts on AWS, particularly monitoring and observability, FinOps Utilising CI/ ...

Senior Software Engineer

Hiring Organisation
Lynx Recruitment Limited
Location
South West London, London, United Kingdom
Employment Type
Permanent
applications while collaborating with architects, engineers and stakeholders to deliver innovative digital solutions. The Role As a Senior Software Engineer, you'll lead the design and development of modern cloud-native applications, working closely with clients to understand business requirements and translate them into robust technical solutions. … contribute to solution design, mentor other engineers, promote engineering best practices, and help shape scalable, resilient platforms built on Microsoft Azure. What You'll Be Doing Design, develop and deliver modern cloud-native applications. Build scalable, secure and resilient event-driven solutions. Develop production-quality software using .NET ...

Senior Software Engineer

Hiring Organisation
Lynx Recruitment Ltd
Location
London, South East, England, United Kingdom
Employment Type
Full-Time
Salary
£75,000 - £105,000 per annum
applications while collaborating with architects, engineers and stakeholders to deliver innovative digital solutions. The Role As a Senior Software Engineer, you'll lead the design and development of modern cloud-native applications, working closely with clients to understand business requirements and translate them into robust technical solutions. … contribute to solution design, mentor other engineers, promote engineering best practices, and help shape scalable, resilient platforms built on Microsoft Azure. What You'll Be Doing Design, develop and deliver modern cloud-native applications. Build scalable, secure and resilient event-driven solutions. Develop production-quality software using .NET ...

Senior Product Engineer

Hiring Organisation
Jobleads-UK
Location
Greater London, England, United Kingdom
contexts Use customer feedback, analytics, and direct user insights to inform technical decisions, prioritise improvements, and validate that shipped features deliver measurable value Design and implement complex data flows, API integrations, and background processing systems that handle high-volume operations reliably while maintaining system performance and data integrity … Partner with product, design, and customers to shape solutions early, translating business requirements into technical architecture while surfacing risks and opportunities that impact customer outcomes Mentor and coach other engineers, raising the bar for technical excellence through code reviews, pair programming, and architectural guidance Beyond the tech ...