51 to 75 of 94 API Design Jobs in the UK

Software Engineer C#, React, .NET

Hiring Organisation
RX Global
Location
Greater London, United Kingdom
Employment Type
Full Time
.NET/C#,, NET Core and familiarity with SQL or data skills Proficiency in Front end tech stack React or Angular Understanding of system design, domain modelling, and API design principles Experience writing unit and integration tests and working with CI/CD pipelines Exposure to cloud ...

Mid-Level Full Stack Developer

Hiring Organisation
Orcha
Location
Warrington, Cheshire, North West, United Kingdom
Employment Type
Permanent
Salary
£45,000
role: We're looking for an experienced Mid-Level Full Stack Developer to join our engineering team and play a significant role in the design, development, and delivery of our products. This role is ideal for someone at the upper end of mid-level, with strong commercial experience across … ready to take real ownership of their work. You will deliver features end to end with minimal supervision, contribute to technical and design decisions, and help raise standards across the team. The role combines hands-on development with a growing influence on how we build software. A key part ...

Director, Forward Deployed Engineering

Hiring Organisation
Jobleads-UK
Location
Greater London, England, United Kingdom
lead a team of elite engineers who embed directly with Fortune 500 customers to ship deeply integrated AI agents—owning everything from agent design and evaluation to the backend services, data systems, and cloud infrastructure that make them production‐ready. You'll partner closely with our Forward Deployed … volume for senior engineering roles. Hands‐on fluency with the full AI stack. Deep familiarity with LLMs and agent systems, evaluation frameworks, backend and API design (Python or TypeScript), data systems (PostgreSQL, DynamoDB, MongoDB, or similar), and cloud infrastructure (AWS, Azure, or GCP) including Kubernetes, Docker ...

Software Engineer - Android Developer

Hiring Organisation
Talent Locker
Location
Cheltenham, Gloucestershire, South West, United Kingdom
Employment Type
Contract
Contract Rate
£500 - £530 per day
experience with: Android development (Kotlin, Jetpack Compose) Backend development (Rust, Python or Go) Git and modern development workflows Docker + CI/CD pipelines API design (REST/OpenAPI) Working in secure or controlled environments Nice to have: AWS or Azure experience Kubernetes Agile delivery experience Secure coding ...

Technical Lead - Ruby

Hiring Organisation
Run-Time Group Ltd
Location
Reading, Berkshire, South East, United Kingdom
Employment Type
Permanent
fast-moving, product-centric environments. Key requirements: Ruby & Ruby on Rails Full-Stack Engineering: JavaScript, TypeScript, React, Hotwire, Stimulus Node.js & React exposure beneficial API Design: REST, GraphQL, external integrations Data Stores: PostgreSQL, MySQL, Redis, Elasticsearch Async Processing: Sidekiq, Resque Cloud & DevOps: AWS, Heroku, Docker, CI/CD pipelines … Testing & Quality: RSpec, Capybara, TDD methodologies Security, performance tuning, and system hardening AI & LLMs: API integration, prompt engineering, AI-enhanced features and developer tooling Responsibilities: Provides hands-on technical leadership to engineering teams (515 people), including mentoring, code review, and architectural direction. Owns end-to-end system architecture, ensuring ...

Full Stack Developer

Hiring Organisation
Ashdown Group
Location
Manchester, Lancashire, England, United Kingdom
Employment Type
Full-Time
Salary
£45,000 - £62,000 per annum
work from home 1 day a week if desired. The salary on offer is £50,000-£62,000 DOE plus good benefits. Key Responsibilities • Design, develop, and maintain scalable web applications using modern frameworks and technologies. • Integrate Twilio APIs for voice, messaging, and video communication features. • Collaborate with product … Twilio APIs (voice, SMS, video) and related integrations. • Proven ability to build and work with real-time, event-driven systems. • Solid grasp of RESTful API design and microservice architecture. • Hands-on experience with AWS serverless technologies including DynamoDB, Lambda, and API Gateway. • Familiarity with CI/ ...

Frontend Engineer JBLE1 NI

Hiring Organisation
Ocho
Location
Belfast, UK
passionate frontend engineering team The Role As a Frontend Engineer, you'll be responsible for: * Leading the development of frontend software components, from design to deployment and maintenance * Contributing to technological and architectural decisions, ensuring high-quality code and user experience * Advocating for product and user experience, ensuring aesthetic … architecture alignment * Designing and reviewing APIs in collaboration with other teams * Analyzing and improving the performance, scalability, and efficiency of system components * Conducting design and code reviews to maintain best practices About You You're a great fit if you have: * 3+ years of experience in frontend engineering using ...

Backend Development Lead

Hiring Organisation
Oyster Consultant
Location
Manchester, North West, United Kingdom
Employment Type
Permanent, Work From Home
Salary
£80,000
evolve our stack and make constant improvements. Required Skills/Experience Strong C# development experience Experience with both .NET Core and .NET Web API Experience of building Microservices in .Net Core Experience using Message Based Architectures Experience using both SQL & NoSQL technologies Experience of API design Cloud ...

Back-End Development Lead

Hiring Organisation
Oyster Consultant
Location
South East London, London, United Kingdom
Employment Type
Permanent, Work From Home
Salary
£80,000
evolve our stack and make constant improvements. Required Skills/Experience Strong C# development experience Experience with both .NET Core and .NET Web API Experience of building Microservices in .Net Core Experience using Message Based Architectures Experience using both SQL & NoSQL technologies Experience of API design Cloud ...

Software Engineer

Hiring Organisation
Corpay
Location
Central London, London, United Kingdom
Employment Type
Permanent, Work From Home
division. This position falls under our Cross Border line of business and is located in London. In this role, you will contribute to the design and development of our eMoney and FX payment systems. You will report directly to the Engineering Manager and collaborate closely with Product, Design … will set you up for success by providing: Assigned workspace or home office setup Company-issued equipment Role Responsibilities Provide significant contribution to the design, development, and maintenance of secure and scalable payment systems. Collaborate with engineering managers, designers, and product teams to gather and analyse requirements, implement technical ...

Python Developer - UK Remote Contract - Outside IR35

Hiring Organisation
Infused Solutions Ltd
Location
Nationwide, United Kingdom
Employment Type
Contract
Agile environment. The ideal candidate will be an experienced Python developer with a strong understanding of modern backend engineering principles, cloud-native development, and API design. Key Responsibilities Design, develop, and maintain scalable backend applications and services using Python Build and optimise RESTful APIs and microservices Develop integrations … between internal and third-party systems Write clean, maintainable, and well-tested code Participate in technical design discussions and architectural decisions Troubleshoot, debug, and resolve complex technical issues Contribute to CI/CD pipelines and deployment processes Collaborate with product, engineering, and DevOps teams to deliver high-quality solutions ...

Software Engineering Manager

Hiring Organisation
Leidos Innovations UK Limited
Location
Farnborough, Hampshire, South East, United Kingdom
Employment Type
Permanent, Work From Home
exciting opportunity to use your experience supporting the Metropolitan Police contract. In this role, you will lead software engineering teams responsible for the design, development, and quality of applications and services. You will provide technical leadership and people management, ensuring engineering standards, best practices, and system integrity are consistently … date Managing interface changes and dependencies Maintaining traceability between ICDs and system requirements Collaborate with architects and technical leads on system design Ensure technical documentation is produced and maintained Support governance, compliance, and audit requirements Basic Qualifications Experience as a Software Engineering Manager or similar role Strong background ...

Senior Java Backend Engineer - Leeds-Based

Hiring Organisation
Jobleads-UK
Location
Leeds, England, United Kingdom
distributed video recording systems and advanced reporting/analytics applications. In this role, you will be deeply involved in hands‐on development, architectural design, and cross‐studio collaboration to advance our internal ecosystem. Key Responsibilities Design & Implementation: Architect and develop robust backend solutions to meet the fast‐paced … challenges of global game development. Technical Leadership: Contribute to the team’s software design guidelines, coding standards, and architectural blueprints. Global Collaboration: Partner and collaborate with other Rockstar technology teams across our worldwide studios. Continuous Innovation: Develop a deep understanding of existing systems while researching and adopting new technologies ...

Fullstack Developer

Hiring Organisation
IO Associates
Location
Bristol, Avon, South West, United Kingdom
Employment Type
Permanent
Essential Strong full-stack experience: comfortable building production frontends (React or similar, TypeScript) and production backend services (Go, Python, Node.js, or similar). Solid API design experience, both REST and event-driven, with an understanding of where each fits. Practical experience with message brokers, streaming, or pub/ ...

Pre-Sales Technical Architect for SaaS Integrations

Hiring Organisation
Jobleads-UK
Location
Greater London, England, United Kingdom
client data will be sourced, validated, and integrated into Mondra, leveraging where possible our existing Import and Export APIs and identifying where custom API development may be required for fulfil Mondra’s data requirements. You will also contribute to the client contracting process, ensuring technical commitments are clearly defined … including mapping data sources, transformation logic, and validation processes. Identify the client’s BI requirements, and define data export strategies (preferably via existing Mondra API). Identify the authentication/authorisation capabilities of the client, and promote the integration with Mondra’s Identity Provider via Single Sign On. Leverage ...

Full Stack Engineer

Hiring Organisation
Total Recruitment Group
Location
West London, London, United Kingdom
Employment Type
Permanent
Salary
£85,000
role, with strong backend expertise in Typescript and Node and front capability in React Proficiency in SQL, Redux, cloud services (AWS or GCP), RESTful API design and GraphQL Strong analytical skills with the ability to design, optimise, and troubleshoot complex UIs Excellent communication and leadership skills; ability ...

Senior Full Stack Engineer (GCP, Python, JavaScript) Remote

Hiring Organisation
Exalto Consulting
Location
London, United Kingdom
Employment Type
Contract
Contract Rate
£400 - £410/day
assisted development workflows. ● Agile Experience: Proven track record working within Agile teams and participating in iterative delivery. ● Core Engineering: Proficiency in Git, REST API design, and modern CI/CD practices This is a great opportunity to work for an exciting organisation and to start ASAP. The role ...

Senior Python Engineer: AI Agents & Forecasting

Hiring Organisation
Jobleads-UK
Location
Greater London, England, United Kingdom
LangChain or LangGraph (agent memory, tool calling, state management) Dagster in production (assets, sensors, partitions) or equivalent pipeline orchestration Strong backend fundamentals including API design, async programming, and database modelling You've built systems that had to work reliably at scale, not just pass a demo Experience 5+ ...

Lead Software Engineer

Hiring Organisation
MARSH CORPORATE SERVICES LIMITED
Location
City of London, London, United Kingdom
Employment Type
Permanent, Work From Home
products (e.g., Concierge an agentic AI workflow tool, Prism a Mercer knowledge fabric for scheme data, and similar initiatives), from problem framing and design through build, release, and support. Translate risk advisory/consulting needs into clear technical requirements, user stories, and solution designs; partner with stakeholders through … Proven experience as a Tech Lead/Lead Engineer delivering production software, including hands-on coding and code review ownership. Strong backend engineering skills (API design, data modelling, performance) and experience building secure, role-based applications. Experience working directly with business stakeholders in a financial firm, with ...

Senior Developer

Hiring Organisation
Addition
Location
London, South East, England, United Kingdom
Employment Type
Full-Time
Salary
£70,000 - £90,000 per annum
improving APIs that support critical platform functionality Investigating production issues and tracing problems across distributed systems Working with product and engineering teams to design scalable solutions Improving reliability, observability and performance across existing services Reviewing code, sharing knowledge and helping raise engineering standards across the team Tackling real-world … APIs used by customers or internal teams Other Skills Needed: Solid backend engineering experience in C#, Java, or Go, with a strong grasp of API design and architecture. Hands-on experience managing and debugging production systems across cloud and self-managed infrastructure. Proven ability to navigate complex third ...

Ruby Developer

Hiring Organisation
Proactive Appointments
Location
London, United Kingdom
Employment Type
Permanent
Salary
GBP 70,000 - 80,000 Annual
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 ...

Ruby on Rails Backend Engineer

Hiring Organisation
Rise Technical Recruitment
Location
Fulham, London, United Kingdom
Employment Type
Permanent
Salary
£60000 - £80000/annum Private Healthcare + Holiday + Pensi
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 ...

Senior Firmware Engineer

Hiring Organisation
Smartbox Assistive Technology
Location
Bristol, Avon, South West, United Kingdom
Employment Type
Permanent, Work From Home
budget and quality requirements, and coordinating others as needed. Firmware Architecture and Lifecycle: Develop reliable, portable firmware with a long-life cycle. Firmware Development: Design, develop and maintain embedded firmware in C for Zephyr RTOS and Embedded Linux, including board bring up, drivers and HALs. Code Quality and Standards … another scientific subject. 8+ years of experience in embedded software development in C. A strong knowledge of Computer Science fundamentals in data structures, algorithm design, problem-solving, and complexity analysis. A strong grounding in embedded software architecture, with a focus on maintainability, modularity, fault-tolerance and testability. Confident ...

AI Solutions Architect

Hiring Organisation
Infosec
Location
Wales, United Kingdom
Employment Type
Permanent
Salary
£90,000
Autogen, Google ADK). Architecting RAG pipelines, vector database integrations, and prompt management strategies. Building guardrail frameworks to prevent hallucinations, injection and bias. Designing API-first and event-driven architectures. Influencing enterprise roadmaps, governance forums and technical standards. Partnering with senior engineers, value streams, and product stakeholders. What … bring Expertise in Azure AI, AWS Bedrock or Google Vertex. Strong experience with LLM evaluation/MES frameworks. Deep knowledge of integration security, API design and cloud-native patterns. Experience delivering solutions in regulated environments (desirable). Naturally proactive, consultative and comfortable influencing at senior levels. ...

Technical Architect - BPSS

Hiring Organisation
Jobleads-UK
Location
East Hagbourne, England, United Kingdom
modernising a complex service-oriented architecture environment. This is a hands‐on architectural leadership role requiring strong stakeholder engagement, technical analysis, and strategic design capability. The successful candidate will play a key role in assessing the current architecture, defining future‐state technical direction, and guiding development teams through scalable … Architect within complex enterprise environments Strong background in service-oriented and distributed system architecture Experience designing scalable, resilient, and maintainable platforms Strong understanding of API design and service communication protocols Experience with messaging technologies and event-driven architectures Knowledge of data integration, data flows, and system interoperability Experience ...