1 to 25 of 59 API Design Jobs in London

Senior Software Engineer

Hiring Organisation
Tiro Partners
Location
City of London, London, United Kingdom
Employment Type
Permanent
Salary
£80000 - £120000/annum
Java/Microservices/API design/LLMs/AI/Claude Code/Copilot Role: Senior Software Engineer Company: Financial Services Location: London - Hybrid 3 days per week Salary: up to £120,000 Join a Service Modernisation team driving AI-first software development in financial services. This … 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 Software 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 Role: Senior Software Engineer Company: Financial Services Location: London - Hybrid 3 days per week Salary: up to £120,000 Join a Service Modernisation team driving AI-first software development in financial services. This … 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 ...

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
City of London, London, 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 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 ...

Remote Software Developer

Hiring Organisation
Turing
Location
City of London, London, United Kingdom
Build agents that can verify the quality of the code and identify error patterns. Hypothesize on steps in the software engineering cycle (prototyping, architecture design, API design, production implementation, launch, experiments, monitoring, operational maintenance) and evaluate model capabilities on them Design verification mechanisms that can automatically … experience. Strong expertise in building full-stack applications and deploying scalable, production-grade software using modern languages and tools. Deep understanding of software architecture, design, development, debugging, and code quality/review assessment. Excellent oral and written communication skills for clear, structured evaluation rationales. Engagement Details: Commitment : flexible engagement ...

Remote Software Developer

Hiring Organisation
Turing
Location
East London, London, United Kingdom
Build agents that can verify the quality of the code and identify error patterns. Hypothesize on steps in the software engineering cycle (prototyping, architecture design, API design, production implementation, launch, experiments, monitoring, operational maintenance) and evaluate model capabilities on them Design verification mechanisms that can automatically … experience. Strong expertise in building full-stack applications and deploying scalable, production-grade software using modern languages and tools. Deep understanding of software architecture, design, development, debugging, and code quality/review assessment. Excellent oral and written communication skills for clear, structured evaluation rationales. Engagement Details: Commitment : flexible engagement ...

Remote Software Engineer

Hiring Organisation
Turing
Location
City of London, London, United Kingdom
Build agents that can verify the quality of the code and identify error patterns. Hypothesize on steps in the software engineering cycle (prototyping, architecture design, API design, production implementation, launch, experiments, monitoring, operational maintenance) and evaluate model capabilities on them Design verification mechanisms that can automatically … experience. Strong expertise in building full-stack applications and deploying scalable, production-grade software using modern languages and tools. Deep understanding of software architecture, design, development, debugging, and code quality/review assessment. Excellent oral and written communication skills for clear, structured evaluation rationales. Engagement Details: Commitment : flexible engagement ...

Remote Software Engineer

Hiring Organisation
Turing
Location
East London, London, United Kingdom
Build agents that can verify the quality of the code and identify error patterns. Hypothesize on steps in the software engineering cycle (prototyping, architecture design, API design, production implementation, launch, experiments, monitoring, operational maintenance) and evaluate model capabilities on them Design verification mechanisms that can automatically … experience. Strong expertise in building full-stack applications and deploying scalable, production-grade software using modern languages and tools. Deep understanding of software architecture, design, development, debugging, and code quality/review assessment. Excellent oral and written communication skills for clear, structured evaluation rationales. Engagement Details: Commitment : flexible engagement ...

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 ...

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

Hiring Organisation
Qim info
Location
London Area, 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 ...

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 ...

Senior Full Stack Developer (React & C#.NET)

Hiring Organisation
Adecco
Location
London, United Kingdom
Employment Type
Contract
Python (pyspark): Experience with data pipelines and analytics is a plus. Power BI: Familiarity with developing dashboards and data models. Architecture: Knowledge of microservices, API design, and event-driven architectures. DevOps/CI/CD: Experience with Azure DevOps, GitLab, GitHub Actions, or similar tools. Cloud Platforms: Proficient … Azure preferred). Databases: Strong skills in SQL Server, PostgreSQL, or other relational databases. containerisation: Experience with Docker and Kubernetes. Key Responsibilities Design & Develop: Create and maintain full stack applications using React JS and C#.NET Core. Build Services: Develop high-performance backend services and RESTful APIs with a focus ...

Solution Architect (Principal Consultant)

Hiring Organisation
Jobleads-UK
Location
Greater London, England, United Kingdom
transformation and ensuring data is protected and used ethically. Talan UK & Ireland provides a range of consultancy and outsourcing capabilities including programme management, market design and governance. We also have extensive and award-winning capabilities across cyber security, data privacy and digital transformation. We are IIP Gold accredited … recruiting an ambitious and technically accomplished Solutions Architect to join our Digital business unit as a Principal Consultant. You will lead the design and delivery of scalable, secure, and cloud-native platforms across Energy (including Low Carbon and UK regulatory systems), Financial Services, Public Sector, and Healthcare domains. This ...

Senior Developer

Hiring Organisation
Reed.co.uk
Location
London, South East, England, United Kingdom
Employment Type
Full-Time
Salary
£80,000 per annum
venture backed by the strength and stability of an established business. Key Responsibilities End-to-end development of high-quality, scalable SaaS platforms from design through deployment and maintenance. Architect and implement robust backend services primarily using Python and PostgreSQL. Develop and maintain responsive, performant front-end applications with … Provide technical mentorship and leadership to development teams, fostering best practices in coding, testing, and deployment. Participate in code reviews, architecture discussions, and system design decisions. Troubleshoot and resolve complex technical issues across the full stack. Ensure software security, scalability, and performance are maintained at all times. Keep abreast ...

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

Hiring Organisation
Salt Search
Location
London, South East, England, United Kingdom
Employment Type
Contractor
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 ...

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 ...

Senior Full Stack Engineer

Hiring Organisation
Prolo
Location
London Area, United Kingdom
PostgreSQL, complex data modelling AI/ML : OpenAI integration, semantic search, conversational agents, unstructured data analysis and extraction Infrastructure : AWS (Lambda, ECS/EKS, API Gateway, S3) DevOps : Terraform, GitHub Actions, Helm, Infrastructure-as-Code Data Science : Graph analytics, data pipelines, ETL workflows, Jupyter notebooks Required Qualifications Software Development … understanding of async programming Experience with Poetry or similar Python dependency management tools Experience building RESTful APIs and micro-services Solid understanding of database design and optimisation (both SQL and NoSQL) Experience with graph databases (Neo4j preferred) or willingness to learn quickly Knowledge of event-driven architectures and message ...

SC Cleared Solution Architect - Permanant

Hiring Organisation
Solirius Limited
Location
London, United Kingdom
Employment Type
Permanent
Salary
GBP Annual
public sector clients, helping to deliver Solirius' services to the highest standard. The role will involve working with multiple business stakeholders, helping them to design business solutions which will then be implemented by the delivery teams. As a Solution Architect, you will be expected to operate with a high … Your role will require innovative thinking, applying best practices and emerging technologies to solve complex business problems in creative and pragmatic ways. Key Responsibilities: Design end-to-end solution architectures that meet business, technical, and security requirements. Translate business and technical requirements into scalable, secure, and cost-effective designs. ...

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 FullStack Developer

Hiring Organisation
Adecco
Location
City of London, London, United Kingdom
Employment Type
Contract
Contract Rate
£600 - £650/day
with CI/CD , microservices , and event-driven architectures is essential, and knowledge of Python (pyspark) for data-driven workflows is advantageous Key Responsibilities Design, develop, and maintain full stack applications using React JS , C#.NET Core , and supporting technologies. Build high-performance backend services, RESTful APIs, and microservices with … calculations, and enterprise-grade BI solutions. Strong understanding of data modeling, performance tuning, and governance in Power BI. Architecture: Strong knowledge of microservices , API design , event-driven architectures , and distributed systems. DevOps/CI/CD: Experience with Azure DevOps, Gitlab, GitHub Actions, or similar. Strong understanding ...

Senior FullStack Developer

Hiring Organisation
Adecco
Location
London, South East, England, United Kingdom
Employment Type
Contractor
Contract Rate
£600 - £650 per day
with CI/CD , microservices , and event-driven architectures is essential, and knowledge of Python (pyspark) for data-driven workflows is advantageous Key Responsibilities Design, develop, and maintain full stack applications using React JS , C#.NET Core , and supporting technologies. Build high-performance backend services, RESTful APIs, and microservices with … calculations, and enterprise-grade BI solutions. Strong understanding of data modeling, performance tuning, and governance in Power BI. Architecture: Strong knowledge of microservices , API design , event-driven architectures , and distributed systems. DevOps/CI/CD: Experience with Azure DevOps, Gitlab, GitHub Actions, or similar. Strong understanding ...

AWS Solution Architect

Hiring Organisation
Anson Mccade
Location
London, United Kingdom
Employment Type
Permanent
Salary
£75,000
impact role delivering large-scale enterprise cloud transformation programmes using AWS. What the Role Involves: As an AWS Solution Architect (Integration Specialist) , you will: Design and deliver AWS cloud-native workloads using serverless, microservices, and containerised architectures Build scalable, resilient, and secure integration solutions across enterprise systems Develop … Salesforce, and Oracle What Youll Need: Hands-on experience as an AWS Solution Architect (Integration Specialist) with Lambda and Kubernetes (EKS) Strong knowledge of API design and security (API Gateway, OpenAPI, OAuth2, JWT) Experience with cloud-native frameworks such as Flask or FastAPI Solid understanding of Kubernetes ...