1 to 25 of 146 API Design Jobs

Java Engineer

Hiring Organisation
Tiro Partners Limited
Location
London, South East, England, United Kingdom
Employment Type
Full-Time
Salary
£80,000 - £120,000 per annum
Java/Microservices/API design/LLMs/AI/Claude Code/Copilot Company: Financial Services Location: London - Hybrid 3 days per week CORE BANKING AND TRADING SYSTEMS EXPERIENCE ESSENTIAL Join a newly formed Service Modernisation & AI team driving AI-first software development in financial services. … development tools (e.g. Claude Code, GitHub Copilot, LLMs) Experience with MCP, AI automation, or agentic AI systems Strong understanding of microservices and API design Java/Microservices/API design/LLMs/AI/Claude Code/Copilot ...

Senior Web Application Developer ASP.NET MVC 5, C#, & React

Hiring Organisation
PCR Digital
Location
Hammersmith, London, United Kingdom
Employment Type
Contract
Contract Rate
£425 - £538/day Inside IR35 to Umbrella
years of Web application development experience consisting of strong C#, ASP.NET MVC 5, and React. Strong knowledge of Object-Oriented Programming, SOLID principles, common design patterns and RESTful API design and integration (experience with SOAP WebServices and XML/XPat) also required. We are looking … Server, Entity Framework, and React experience desirable to have HTML5, CSS3, JavaScript, jQuery. * Strong knowledge of Object-Oriented Programming, SOLID principles, and common design patterns. * Experienced in RESTful API design and integration; experience with SOAP WebServices and XML/XPath. * Skilled in using IoC containers (Autofac, Ninject ...

Senior Software Engineer

Hiring Organisation
Expedia Group
Location
London Area, United Kingdom
across Expedia’s white-label and partner platforms. We’re building the next generation of video ad infrastructure, AI-powered tooling, and Rapid API integrations to deliver smarter, more engaging ad experiences. In this role, you will: Design, implement, and evolve high-quality software services and components, including … system design, low-level design, API design, and data modeling to support scalable, reliable products. Lead end-to-end delivery of complex technical features across services or domains, including requirements clarification, solution design, development, testing, deployment, and ongoing operational support. Collaborate closely with product, architecture ...

Lead Backend Engineer - Assistance

Hiring Organisation
N26 GmbH
Location
Berlin, Germany
Employment Type
Permanent
Salary
EUR Annual
well as working with a high degree of autonomy. Who we are N26 has reimagined banking for today's digital world. Technology and design empower everything we do and it's how we are building the global banking platform the world loves to use. We've eliminated physical branches … tech scope: work hand in hand with PM and EM to manage product technical roadmaps and dependencies to minimise technical debt. Architect & Build: Design, develop, and maintain high-availability, high-performance web applications that serve as the backbone of our internal operations. Foster tech-solid delivery: Drive the team ...

Lead Backend Engineer - Assistance

Hiring Organisation
N26 GmbH
Location
Potsdam, Brandenburg, Germany
Employment Type
Permanent
Salary
EUR Annual
well as working with a high degree of autonomy. Who we are N26 has reimagined banking for today's digital world. Technology and design empower everything we do and it's how we are building the global banking platform the world loves to use. We've eliminated physical branches … tech scope: work hand in hand with PM and EM to manage product technical roadmaps and dependencies to minimise technical debt. Architect & Build: Design, develop, and maintain high-availability, high-performance web applications that serve as the backbone of our internal operations. Foster tech-solid delivery: Drive the team ...

Senior Software Developer

Hiring Organisation
Birketts LLP
Location
Sevenoaks, Kent, England, United Kingdom
Employment Type
Full-Time
Salary
Competitive salary
This is a hands-on software engineering role, ideal for someone who thrives on solving complex problems in a collaborative, agile environment. You will: Design, develop and test Azure cloud native software using C# and .Net technologies, in line with an agreed schedule Ensure code is testable, safe, functional … secure, performant and reliable, all proven through testing Apply software development, microservices and API design best practices, and participate in code reviews Produce relevant and high standard documentation, developer-level tests, and deployment procedures Give accurate task estimates, and provide progress status to management Collaborate with cross-functional ...

Lead Full Stack Developer

Hiring Organisation
Goodman Masson
Location
London, South East, England, United Kingdom
Employment Type
Full-Time
Salary
£80,000 - £100,000 per annum
shaping Meteor's digital future. Key Responsibilities Lead, mentor, and inspire a team of developers, fostering a culture of technical excellence and continuous improvement Design, develop, and maintain high-quality software solutions across the full stack Architect and implement systems using .NET, JavaScript, SQL, and modern frontend frameworks Oversee … API design and integrations, ensuring secure and efficient data exchange Translate business and stakeholder requirements into clear technical solutions Conduct code reviews and ensure adherence to coding, security, and quality standards Drive continuous improvement in development workflows, testing, and deployment practices Support the professional development of team members ...

Product Manager – Global Card Issuing Platform (BaaS)

Hiring Organisation
WorldFirst
Location
London Area, United Kingdom
infrastructure that allows clients to launch card programs anywhere in the world through a single integration. You will be responsible for a unified Global API and SDK suite that abstracts the complexity of regional payment networks. Whether a client is launching in Europe, North America, or APAC, your product … will provide a consistent, white-label experience. You will drive both the technical "how" (API/SDK design) and the strategic "where" (global expansion and regional issuing setups). What you’ll do: Unified Global API Strategy: Design and maintain a single, polymorphic API architecture ...

Staff Engineer

Hiring Organisation
Tata Consultancy Services
Location
London Area, United Kingdom
matters, through challenging projects which demand ambitious innovation and thought leadership. The Role As a Staff Engineer (Backend – Java), you will be lead the design and development of highly scalable, resilient, and performant backend systems. This role is suited for a hands-on technical leader who can set engineering … drive complex solutions across multiple teams. Your responsibilities: Technical Leadership Evolve the technical strategy and architectural direction for backend services and distributed systems. Design scalable, fault-tolerant, event-driven, and cloud-native backend architectures. Lead complex engineering initiatives spanning multiple teams, domains, or platforms. Provide deep hands-on expertise ...

Head of Forward Deployment Engineering

Hiring Organisation
Triple
Location
United Kingdom
agents to connect with any core banking system, card processor, or dispute platform Own the technical quality of every client integration, from secure API design and data pipeline reliability to compliance with bank-grade security requirements Create scalable deployment tooling, integration templates, and automation that reduce time … Deep experience integrating with enterprise systems in financial services, payments, or similarly regulated industries Strong proficiency in Python and SQL. Hands-on experience with API design, data pipelines, and infrastructure automation Track record of building engineering teams or functions from early stage, including hiring, process design ...

C# / .Net Software Engineer (Freelance / contractor)

Hiring Organisation
Qim info
Location
City of London, London, United Kingdom
collaborate with international clients and are looking for skilled contractors to support project-based engagements. 📄 Your responsibilities: The objective of this role is to design, build, and govern an API integration layer connecting multiple internal and external systems within a complex energy trading environment. 💼 Required technical skills: API … Integration Architecture: Strong expertise in API integration, REST API design and exposure, interface-driven architectures, integration-heavy environments, abstraction layers, system decoupling Backend Development: .NET Core, C#, API services, integration services Architeture & Platforms: Design of scalable and reusable integration layers, interoperability with multiple systems (internal ...

Lead Software Engineer

Hiring Organisation
Corporate Travel Management (CTM) Group
Location
United Kingdom
right person will be able to break down complex problems from first principles, determine where deterministic logic versus probabilistic systems are most appropriate, and design scalable, secure, maintainable solutions that combine both effectively. You will work across front-end, back-end, APIs, workflows, and system architecture, while helping … someone who can make sound decisions about how intelligent systems should actually be designed, governed, and operated in production. Specialized Skills: Microservices architecture and API design Container orchestration (Kubernetes/Docker) Database design and optimization (SQL/NoSQL) Security best practices and implementation Comfortable with event driven ...

Principal Software Solutions Architect

Hiring Organisation
Moorepay
Location
Manchester, Lancashire, England, United Kingdom
Employment Type
Full-Time
Salary
Competitive salary
technical authority responsible for defining, governing, and evolving the end-to-end architecture of our “AI First” platform, ensuring architectural consistency, secure-by-design principles, and long-term scalability across all engineering squads. Working closely with the Engineering Manager, Cloud & Platform Engineering Lead, and Product leadership, this role shapes … excellence, and provides deep guidance to multiple autonomous squads as we scale towards high-performing, cloud-native teams. The Architect balances hands-on solution design, strategic planning, technical oversight, and stakeholder collaboration to keep the platform robust, secure, and ready for future growth. This role defines the architectural backbone ...

Cloud Data IT Architect (H/F)

Hiring Organisation
Airbus
Location
Castanet-Tolosan, Haute-Garonne, France
Employment Type
Permanent
Salary
EUR Annual
System & Test" DataHub within the PLM family. As part of the Information Management (IM) organization, you will be involved in Cloud and Data architecture design aiming at securing digital continuity and business innovation. Your working environment: Global capital of aeronautics and European capital for space research, Toulouse … more easily and flexibly. Wherever possible, we foster flexible working arrangements to stimulate innovative thinking. Your challenges: Translate business needs into IT requirements and design Architecture Dossiers (ArchiMate, UML). Design End-to-End data transformation pipelines and related APIs (Spark, SQL, REST). Design distributed Cloud ...

Principal Engineer (Agentic AI)

Hiring Organisation
CleverChain
Location
United Kingdom
Principal Software Engineer to join as one of the first hires on this platform. You'll work across the full backend, from database schema design and API implementation through to workflow orchestration, AI integrations, and infrastructure. This isn't maintenance work. It's building. The platform has genuine … extend the platform engine — new workflow node types, control flow improvements, human-in-the-loop infrastructure, provider capabilities, and tooling that product teams consume Design for scale and performance — optimise data storage patterns, manage connection pooling across a large number of tenant databases, reduce latency in high concurrency multi ...

Principal Software Engineer (Payments)

Hiring Organisation
X4 Technology
Location
City of London, London, United Kingdom
their latest platform, provide technical expertise at both the architectural and hands-on development levels, and mentor junior team members. What You’ll Do: Design and build scalable payment applications and APIs Develop modern frontend interfaces and backend services Integrate with payment providers and financial systems Optimise database performance …/Angular), HTML5, CSS3 Backend: Python REST APIs Data: MySQL, PostgreSQL, Redis Cloud & DevOps: AWS, Docker, CI/CD, Kubernetes (nice to have) Architecture: API design, OAuth/JWT authentication, queues, webhooks, payment integrations Previous experience in Financial Services What We’re Looking For: Strong system design ...

Application Integration Architect

Hiring Organisation
IT Talent Solutions
Location
Milton Keynes, Buckinghamshire, United Kingdom
Employment Type
Permanent
Salary
£50000 - £70000/annum excellent benefits and bonus
Application Integration Architect Role Overview We are looking for an experienced Application Integration Architect to lead the design and delivery of scalable, high-performance integration solutions across enterprise systems. This role sits at the intersection of architecture, engineering, and business transformation—driving seamless interoperability between platforms while ensuring reliability … cross-functional teams, including engineering, operations, vendors, and business stakeholders, to define and implement robust integration strategies aligned with enterprise architecture principles. Key Responsibilities Design and architect end-to-end integration solutions using modern integration patterns (e.g., event-driven, microservices, API-led connectivity). Translate complex business requirements ...

Integration Architect

Hiring Organisation
IT Talent Solutions Ltd
Location
Milton Keynes, Buckinghamshire, England, United Kingdom
Employment Type
Full-Time
Salary
£50,000 - £70,000 per annum
Application Integration Architect Role Overview We are looking for an experienced Application Integration Architect to lead the design and delivery of scalable, high-performance integration solutions across enterprise systems. This role sits at the intersection of architecture, engineering, and business transformation—driving seamless interoperability between platforms while ensuring reliability … cross-functional teams, including engineering, operations, vendors, and business stakeholders, to define and implement robust integration strategies aligned with enterprise architecture principles. Key Responsibilities Design and architect end-to-end integration solutions using modern integration patterns (e.g., event-driven, microservices, API-led connectivity). Translate complex business requirements ...

Data Integration Engineer

Hiring Organisation
GlobalLogic
Location
City of London, London, United Kingdom
GlobalLogic, a Hitachi Group Company and a leader in digital engineering. We help brands across the globe design and build innovative products, platforms, and digital experiences for the modern world. By integrating experience design, complex engineering, and data expertise - we help our clients imagine what’s possible … Experience with: Experience with Python for data pipelines, export services, ETL, reconciliation, profiling scripts Data quality assessment Apache Kafka PostgreSQL for data modelling, query design, migrations etc Data modelling and schema design REST API design Ideally you will have: Experience of C# to be able ...

Senior Java Software Engineer

Hiring Organisation
Salt
Location
West Sussex, England, United Kingdom
engineering discipline, independent problem‐solving ability, and a commitment to building robust, scalable systems. You will work across modern cloud‐native architectures, contribute to API and microservices development, and help drive best practices across the engineering organisation. Key Responsibilities Design, develop, and maintain high‐quality Java applications using … Spring Boot. Build and optimise RESTful APIs and contribute to GraphQL service development. Develop cloud‐native solutions using AWS services such as Lambda, API Gateway, DynamoDB, ECS, S3, and others. Contribute to microservices architecture, event‐driven systems, and distributed design patterns. Implement CI/CD pipelines using tools ...

Senior Java Engineer (AWS, REST, SOAP) - Hybrid - Sussex

Hiring Organisation
Salt
Location
London, United Kingdom
Employment Type
Contract
Contract Rate
£500 - £700 per day
engineering discipline, independent problem-solving ability, and a commitment to building robust, scalable systems. You will work across modern cloud-native architectures, contribute to API and microservices development, and help drive best practices across the engineering organisation. Key Responsibilities Design, develop, and maintain high-quality Java applications using … Spring Boot. Build and optimise RESTful APIs and contribute to GraphQL service development. Develop cloud-native solutions using AWS services such as Lambda, API Gateway, DynamoDB, ECS, S3, and others. Contribute to microservices architecture, event-driven systems, and distributed design patterns. Implement CI/CD pipelines using tools ...

Lead AI Engineer

Hiring Organisation
KPMG UK
Location
City of London, London, United Kingdom
Data Analytics, and Software Development, the team is revolutionising the auditing process to deliver smarter, faster, and more reliable outcomes. Our mission is to design and implement robust, intelligent, and scalable technologies that not only streamline workflows but also enhance audit quality and generate actionable insights for auditors … backend development as a Senior role. Languages/Frameworks: Strong proficiency in Python with hands-on experience in asynchronous programming, concurrency and multithreading. API Expertise: Proven experience in building and integrating APIs, with expertise in API documentation and schema definition using OpenAPI/Swagger. Strong understanding of RESTful ...

Software Developer

Hiring Organisation
Erin Associates
Location
Birmingham, West Midlands, United Kingdom
Employment Type
Permanent
Salary
£55,000
SoftwareDeveloper(API Development/Backend Node.js, C#, Fullstack) Birmingham, West Midlands (Hybrid 1 day onsite a week) 55k + Benefits Were partnering with a leading enterprise software house in Birmingham that is expanding its engineering team. Theyre looking for a Software Engineer with strong API and backend development … power enterprise software products. Youll work primarily with Node.js and C#, collaborating with cross-functional teams to deliver well-architected, maintainable solutions. Key Responsibilities Design, build, and maintain RESTful APIs and backend systems. Develop high-quality, scalable code using Node.js and C#. Collaborate with product and engineering teams ...

Software Engineer - Data Platform for Trading

Hiring Organisation
Harrington Starr
Location
City of London, London, United Kingdom
large-scale financial data platform, modernising legacy enterprise systems while building scalable cloud-based services on AWS. Own SQL Server optimisation, backend service design, and API development in a high-impact platform modernisation initiative. What You'll Do Develop and optimise SQL Server queries, stored procedures, and data … processing logic Design and build backend services in Python or C# Modernise legacy platforms and improve system performance Build and maintain AWS-hosted services and APIs Collaborate with distributed engineering and product teams Top Skills Required Advanced SQL Server expertise (performance tuning, indexing, complex queries) – non-negotiable Backend development ...

AWS Solution Architect - Integration Specialist

Hiring Organisation
Anson Mccade
Location
East London, London, United Kingdom
Employment Type
Permanent
Salary
£75,000
focused on designing and delivering modern, cloud-native integration solutions across complex enterprise environments. You'll work across the full lifecycle - from architecture and design through to implementation - leveraging AWS services and best practices to build scalable, secure, and high-performing systems. You'll collaborate closely with clients … include: Designing and implementing AWS-based integration solutions using serverless, microservices, and containerised architectures Building scalable and resilient applications using services such as Lambda, API Gateway, and Kubernetes (EKS) Developing and managing CI/CD pipelines and automation frameworks Applying cloud security best practices, including IAM, encryption, and compliance ...