26 to 50 of 56 API Design Jobs in London

VodafoneThree - Solution Architect

Hiring Organisation
Vodafone
Location
London, UK
Employment Type
Full-time
solution designs, including key non-functional requirements such as security, performance, resilience and maintainability. You'll possess a strong understanding of REST APIs and API design best practices. You'll have working knowledge of event-driven architecture and related design principles. You'll be able to communicate ...

Principal Product Engineer

Hiring Organisation
Zapp
Location
London, UK
Employment Type
Full-time
creates real customer value, prototype the hardest bets yourself, and bring the team with you. Own delivery end-to-end. Pick up a problem, design the solution, ship the work wherever the feature lives, and see it through to production. Own on-call. Be on the rotation, and stand … just code. You measure your work by what changed for the customer, not the lines of code shipped. Production minded. Solid grasp of API design, observability, scaling, reliability, and security. Care about craft. Clean APIs, attention to detail, and how the system feels to work in. Comfortable ...

Senior Solutions Engineer

Hiring Organisation
Hackajob Ltd
Location
South West London, London, United Kingdom
Employment Type
Permanent
works with top tier global financial institutions and major tech companies to offer our client products and services directly to their customers. Through our API, we help partners to architect and build integrations to our world class-leading international finance products, which in turn improves our client by increasing … turnaround times. Designing and developing innovative new features that expand the functionality of our client's services and exposing these features through the public API, enabling seamless integration with partner systems and empowering them to leverage the full potential of our client's platform. Diagnosing and resolving complex technical ...

Finance AI Engineer (Consultant)

Hiring Organisation
Accenture
Location
London, UK
Employment Type
Full-time
including Python and at least one additional production language such as TypeScript or equivalent, version control, testing, CI, and maintainable code, together with SQL, API design, code review and secure coding practices. Hands-on LLM application development, covering tool use, structured outputs, retrieval and agent frameworks, including embeddings ...

Finance AI Engineer ( Manager )

Hiring Organisation
Accenture
Location
London, UK
Employment Type
Full-time
including Python and at least one additional production language such as TypeScript or equivalent, version control, testing, CI, and maintainable code, together with SQL, API design, code review and secure coding practices. Hands-on LLM application development, covering tool use, structured outputs, retrieval and agent frameworks, including embeddings ...

Full Stack Software Engineer - Global Trading Firm

Hiring Organisation
Robert Walters
Location
London, South East England, United Kingdom
Employment Type
Full-Time
Salary
£600.00 - £700.00 per day
high-impact engineering role combining hands-on full-stack development, scalable architecture and direct collaboration with front-office stakeholders. What you'll be doing Design and build modern applications using React or Vue.js and Java-based back-end services. Develop distributed microservices, APIs and scalable enterprise architectures, with Python … solutions using AWS, Azure or GCP, alongside CI/CD pipelines and automated testing. Optimise application performance, security, reliability and production support. Lead technical design, code reviews and testing, resolve complex engineering challenges and mentor other developers. Work directly with portfolio managers, product owners and cross-functional teams ...

Full Stack Java Developer

Hiring Organisation
Hackajob Ltd
Location
South West London, London, United Kingdom
Employment Type
Permanent, Work From Home
security etc). Working within a project management/agile delivery methodology Experience in technical ownership for a product or software solution, covering design, estimation, shaping and user story/requirement creation Documentation of solutions (e.g. architecture, configuration, release, support-handover Collaborate and liaise with other our client … including microservices and message-driven architectures NFR/Non-Functional requirement understanding and experience developing applications with this in mind Application/Digital Services Design experience Experience in software engineering practices like Code Reviews, CI/CD Pipelines and SOLID/DRY principals Hands-on developing/coding role ...

VP, Senior Backend Developer - Blockchain Infrastructure

Hiring Organisation
Galaxy Digital
Location
London, UK
Employment Type
Full-time
Selective To Be Effective. Be Highly Aligned, Loosely Coupled. Disagree Transparently. Encourage Independent Decision-Making. Build Dream Teams. Who You Are: You'll design and build backend systems powering blockchain infrastructure and staking products across Galaxy — spanning Ethereum-based systems, staking infrastructure (native and liquid), and blockchain data systems … first development environment that increasingly leverages AI-assisted workflows. Typical time allocation: roughly 60% building systems and features, 20% code review and mentorship, 20% design, architecture, and product collaboration. What You'll Do: Build and own backend systemsDesign and build APIs, services, Ethereum data pipelines and indexers, staking ...

Senior Application Security Engineer - DevSecOps & Cloud Security

Hiring Organisation
Additional Resources
Location
London, UK
Employment Type
Full-time
applications, platforms and deployment processes. This is not a traditional vulnerability management role, it is a hands-on Application Security role centred on secure design, CI/CD security, cloud-native technologies, Kubernetes, API security, code analysis, security-as-code and supporting development teams to build secure applications. … controls throughout CI/CD pipelines. Strengthening the security of GitHub Actions and comparable continuous integration and deployment platforms. Providing technical guidance on secure API design and protecting externally accessible systems. Supporting the security of Azure cloud infrastructure, including Azure Kubernetes Service (AKS).Assisting with the protection ...

Lead Developer

Hiring Organisation
Circle Recruitment
Location
London, South East England, United Kingdom
Employment Type
Full-Time
Salary
£600.00 - £629.00 per day
within a multidisciplinary or agile delivery team, including coaching, mentoring, pairing, coordinating technical work and helping teams apply good engineering practices consistently. Ability to design, review and deliver systems with medium to high levels of technical or business complexity, ensuring appropriate technology choices, secure design, maintainability, performance, integration … adherence to modern standards Automated testing, CI/CD, reusable components, observability, secure development, API design, systems integration and continuous improvement of developer experience. The role is likely to suit someone who can operate confidently as the bridge between strategic technical direction and practical delivery within a squad. ...

Senior Application Security Engineer / DevSecOps Engineer

Hiring Organisation
Additional Resources
Location
London, United Kingdom
Employment Type
Permanent
teams to integrate security throughout the software development lifecycle. Microsoft Azure and KQL experience are essential , alongside relevant experience in CI/CD, Kubernetes, API security, security-as-code and security automation . This is a hands-on application security role focused on secure design, application security testing … Integrating security controls into CI/CD pipelines. Strengthening the security of GitHub Actions and similar CI/CD platforms. Providing guidance on secure API design and externally accessible systems. Supporting Azure cloud infrastructure, including Azure Kubernetes Service (AKS). Developing security-as-code and policy-as-code. ...

Technical Architect

Hiring Organisation
McGregor Boyall
Location
London, South East England, United Kingdom
Employment Type
Full-Time
Salary
£750.00 - £850.00 per day
Processing, and Cash & FX. You'll act as the technical authority within delivery teams, driving architecture strategy, governance, and engineering best practice. Key Responsibilities Design modern microservices and event-driven architectures using technologies such as Kafka, REST APIs and cloud platforms. Lead architecture governance, technical reviews, non-functional requirements … Processing Strong software engineering background in Java, Spring Boot, Oracle and SQL databases. Proven experience with: Microservices architecture Event-driven systems (Kafka, MQ, Solace) API design and integration AWS and/or Snowflake Knowledge of SWIFT MT, ISO 20022 and post-trade processing workflows. Experience operating within enterprise ...

Data Platform Architect

Hiring Organisation
ComplySci
Location
London, UK
Employment Type
Full-time
data products, the security master, semantic models, lakehouse technologies, APIs, event-driven services, AI interfaces, and analytics platforms. Establish architectural standards for interoperability, including API design, event contracts, data exchange patterns, versioning, and access controls. Define scalable integration patterns for customers, partners, and enterprise systems across API … technologies or knowledge graphs. Event streaming platforms. MCP or AI integration frameworks. Enterprise integration patterns. Financial services or RegTech experience. Identity and access management. API management platforms. To learn more about our values, mission and the wide-range of perks offered to employees at Comply, visit .Comply ...

Backend Engineer

Hiring Organisation
Harnham - Data & Analytics Recruitment
Location
London, South East England, United Kingdom
Employment Type
Full-Time
Salary
£70,000 - £80,000 per annum
including APIs, workflow engines, data services, and system integrations. Develop and support integrations between Java/Spring platform components and Python-based AI services. Design secure, reliable, and high-performance systems. Collaborate with cross-functional engineering teams to deliver robust backend solutions for demanding production environments. Implement and enhance … API architectures, observability frameworks, automated testing, and security best practices. Contribute to cloud infrastructure, CI/CD pipelines, and operational excellence across AWS-based environments. YOUR SKILLS AND EXPERIENCE : Strong commercial experience building backend applications. Strong Python experience is essential, with FastAPI as highly desirable Strong SQL and PostgreSQL ...

AI Software Engineer

Hiring Organisation
Matchtech
Location
London, UK
Employment Type
Full-time
level role focuses on building intelligent AI agents that can plan, reason, operate security tooling and identify exploitable vulnerabilities within controlled environments. Key Responsibilities: Design, build and deploy AI agents that automate penetration testing, including planning, tool use and reasoning over security findingsDevelop sandboxed cyber-lab and range infrastructure … using containers and KubernetesDeliver AI features from initial design through to production, including evaluations, guardrails and monitoringImprove agent performance through prompt engineering, tool orchestration, evaluation and token and cost optimisationIntegrate security tools and enable agents to operate safely within defined scopesWork closely with security researchers to translate offensive security ...

Senior Software Developer - Wise Platform

Hiring Organisation
Wise
Location
London, UK
Employment Type
Full-time
work: We're a small team that ships frequently and iterates on real partner feedback. Engineers own features from technical discovery and design through to production support. We work closely with our PM and designer to understand partner needs, and with adjacent teams (API Experience, Account Discovery … identity mapping between partner systems and Wise. The communication layer services between Wise and partners, extending them to handle new case types and workflows. API design for partner-facing endpoints. We care about consistency, documentation, and making them usable without hand-holding. Work with FinCrime, Compliance ...

Senior React & Node Developer (AI & Full Stack)

Hiring Organisation
Infused Solutions Ltd
Location
London, United Kingdom
Employment Type
Permanent
Salary
£65000 - £75000/annum
part of a small, highly experienced engineering team responsible for transforming ambitious ideas into production-ready software. Working closely with Product, Design and AI specialists, you'll take concepts from whiteboard sketches through to prototypes, proof of concepts, MVPs and ultimately scalable products. If you enjoy solving complex problems … frontend development, backend engineering and cloud technologies to rapidly build and validate new AI-powered products. You'll be heavily involved in architecture, technical design and proof-of-concept development, collaborating directly with stakeholders to transform ideas into working software. This is a hands-on engineering role where ...

ML Ops Engineer

Hiring Organisation
CMC Markets
Location
London, South East England, United Kingdom
Employment Type
Full-Time
Salary
Competitive salary
What you’ll bring 3–7 years’ experience in ML Ops, ML platform or infrastructure engineering, or backend engineering. Strong production Python skills, including API design, testing and maintainable services. Experience deploying and operating ML models in production. Familiarity with the ML lifecycle, from training and validation through … Experience with CI/CD and workflow orchestration. Comfort working with cloud infrastructure, containers and infrastructure as code. A sound understanding of observability, system design and common failure modes in ML systems. The ability to weigh reliability and operational trade-offs, and communicate clearly across teams. Nice to have ...

Scala Developer

Hiring Organisation
SF Partners
Location
London, United Kingdom
Employment Type
Permanent
Salary
GBP 75,000 - 85,000 Annual
following key skills: - At least three years commercial scala programming - Strong framework experience (Akka, Play etc) - Relational database experience - PostgreSQL - MongoDB, NoSQL - RESTful API design and integration experience - Solid unit test understanding - Spec2, scalaTest etc - Experience working in a TDD/BDD driven environment - Containerization experience - Docker, Kubernetes … well-established friendly team then please apply now to be considered and for further details. Scala Developer Up to £85,000 Scala, REST Api, NoSQL, TDD/BDD, functional programming, CI/CD, Play, Akka ...

Scala Developer

Hiring Organisation
SF Partners Admin
Location
South West London, London, United Kingdom
Employment Type
Permanent, Work From Home
Salary
£85,000
following key skills: - At least three years commercial scala programming - Strong framework experience (Akka, Play etc) - Relational database experience - PostgreSQL - MongoDB, NoSQL - RESTful API design and integration experience - Solid unit test understanding - Spec2, scalaTest etc - Experience working in a TDD/BDD driven environment - Containerization experience - Docker, Kubernetes … well-established friendly team then please apply now to be considered and for further details. Scala Developer Up to £85,000 Scala, REST Api, NoSQL, TDD/BDD, functional programming, CI/CD, Play, Akka ...

Lead Software Engineer, Team Lead

Hiring Organisation
Marsh & McLennan Companies
Location
London, UK
Employment Type
Full-time
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 ...

AI Architect / Engineer (Agentic AI & LLM Architecture)

Hiring Organisation
Talan
Location
London, UK
Employment Type
Full-time
DescriptionAs our AI practice scales, we are seeking an experienced AI Architect/Engineer to act as the senior technical authority shaping how we design and deliver next-generation AI solutions. This is a role for someone who has moved beyond building individual models to architecting entire systems: agentic … ambiguous business problems into robust, deployable architectures. As engagements mature, you will provide the technical oversight that keeps delivery teams aligned to the original design intent. Your influence will be felt in pre-sales conversations, solution blueprints, and the technical standards that define how our practice builds. This ...

Full Stack .net Core Developer - Fintech50- Bath

Hiring Organisation
Quant Capital
Location
London, UK
Employment Type
Full-time
/3Strong C#NET WebAPIDocument oriented databases (MongoDB, DocumentDB or others)GraphQL experience (Frontend/backend)Strong React/TypeScriptSingle Page ApplicationBDD/TDDESTful API design and developmentKnowledge and experience with Git and GithubCloud experience will be gained as they are currently running a massive migration and development project … packages in the market, all inclusive. My client is based in Bath.net core, ASP.NET MVC, razor, c#, sql, mvc, .net, javascript, greenfield, , data, analytics, api, jquery ...

Angular Developer

Hiring Organisation
Lime Street Recruitment Limited
Location
City of London, London, United Kingdom
Employment Type
Permanent
Salary
£45,000
core business systems. This is a hands-on development role working closely with other Developers, Business Analysts, Testers and Product Owners to design, build and support high-quality, maintainable software. In particular: Designing and developing robust Modern .Net (C#) and Angular solutions that support critical business processes Building well … knowing how to manage those risks. SKILLS REQUIRED You will be comfortable working in a collaborative development team, understanding business requirements, contributing to technical design decisions and delivering well-structured code that is reliable, maintainable and easy to support. You will be able to demonstrate: Strong commercial experience with ...

Senior iOS Engineer

Hiring Organisation
Randstad Technologies Recruitment
Location
London, United Kingdom
Employment Type
Contract
Contract Rate
£498 - £664/day
partners across product, legal, policy, and design. What We're Looking For 8+ years of professional iOS development experience with modern Swift and Cocoa design patterns. Agentic workflow adoption: Hands-on experience integrating tools like Cursor and Claude into daily engineering. Platform & API design: Proven track record ...