1 to 25 of 53 API Design Jobs in London

Technical Architect

Hiring Organisation
IPS Group
Location
London, United Kingdom
Employment Type
Permanent
designed to enable long-term career progression. Role Summary Our client is seeking an experienced Technical Architect with strong expertise in integration architecture, systems design best practice, and API design. The role will take technical ownership of the organisations enterprise technology landscape. This is a pivotal position within … wide integration strategy, including the governance of integration patterns (such as synchronous APIs, event-driven architecture, asynchronous messaging, and batch ETL). Lead the design and documentation of internal and external APIs, ensuring best practice in RESTful design, versioning, and OpenAPI standards. Work with Engineering and Data teams ...

Technical Architect

Hiring Organisation
IPS Group
Location
London, South East, England, United Kingdom
Employment Type
Full-Time
Salary
£100,000 - £120,000 per annum
designed to enable long-term career progression. Role Summary Our client is seeking an experienced Technical Architect with strong expertise in integration architecture, systems design best practice, and API design. The role will take technical ownership of the organisation’s enterprise technology landscape.This is a pivotal position within … wide integration strategy, including the governance of integration patterns (such as synchronous APIs, event-driven architecture, asynchronous messaging, and batch ETL). Lead the design and documentation of internal and external APIs, ensuring best practice in RESTful design, versioning, and OpenAPI standards. Work with Engineering and Data teams ...

Mulesoft Developer

Hiring Organisation
Experis
Location
London, United Kingdom
Employment Type
Contract
Contract Rate
£470 - £520/day
Project Manager, architects, clients & other stakeholders to implement MuleSoft APIs. This role will require knowledge of MuleSoft's Anypoint Studio & Anypoint Platform, which includes Design Center, Runtime Manager, API Manager, Exchange, etc. You must be capable of understanding business requirements, working with stakeholders & implementing complex integrations. Responsibilities: Designing … stakeholders to understand business requirements & translate them into integration solutions. Required Skills: Good experience of: Integration concepts & technologies. MuleSoft Anypoint Platform & components (Mule ESB, API Manager, CloudHub, etc.) Java programming & experience with other programming languages such as XML, JSON, SQL Agile software development methodologies. Cloud-based integration platforms such ...

Senior Backend Engineer

Hiring Organisation
Reelables
Location
London Area, United Kingdom
data streams, ensures millisecond latency for global supply chains, and scales seamlessly as we grow from millions to billions of tracking events. Think API performance and data processing efficiency meets cutting-edge innovation. You'll be designing highly performant and distributed services that ingest and process location and temperature … breakthrough technology is already transforming how companies track and manage their shipments globally, and we're just getting started. Responsibilities Core Service Architecture & Scale Design, develop, and maintain highly scalable back-end services that handle millions of concurrent data ingestion events and user requests. Architect and optimize data processing ...

Staff Software Engineer- (Optimizely Analytics, Backend)

Hiring Organisation
Optimizely
Location
London, England, United Kingdom
will work in a small, nimble team. Our team prides itself on shipping with speed and having our engineers be make product and design decisions with ownership and autonomy. As the newest addition to the Optimizely product portfolio, with a rapidly growing customer base there is tremendous opportunity … shaping the foundation of Optimizely Analytics’ backend systems and scaling them to meet the needs of our rapidly growing customer base. You will: Design and evolve the architecture of highly scalable, reliable, and secure distributed systems. Drive technical excellence across the engineering organization by setting standards for code quality ...

Corporate Solutions Engineering, UK

Hiring Organisation
Postman
Location
London, England, United Kingdom
Postman is the world’s leading API platform, used by more than 40 million developers and 500,000 organizations, including 98% of the Fortune 500. Postman is helping developers and professionals across the globe build the API-first world by simplifying each step of the API lifecycle … Insight Partners, and Nexus Venture Partners. Learn more at postman.com or connect with Postman on X via @getpostman. P.S: We highly recommend reading The "API-First World" graphic novel to understand the bigger picture and our vision at Postman. Account Strategy Lead technical discovery sessions to uncover customer challenges ...

Senior API Technical Consultant (GraphQL Specialist)

Hiring Organisation
Staffworx Limited
Location
London, United Kingdom
Employment Type
Contract
Contract Rate
GBP Annual
Senior API Technical Consultant (GraphQL Specialist) Design and build next generation of high-scale SaaS platforms. We're looking for a senior/lead engineering consultant with deep expertise in GraphQL to take a leading role in developing our robust TypeScript/Node.js Back End. You will … evolution of our APIs, ensuring our services are resilient, scalable and secure within a cutting-edge, cloud-native environment (Helm, Kubernetes). The Deliverables Design and build sophisticated, scalable GraphQL APIs and Back End services using TypeScript and Node.js. Lead the design and evolution of our API ...

Fullstack Developer - SC Cleared

Hiring Organisation
LA International Computer Consultants Ltd
Location
London, United Kingdom
Employment Type
Contract
Contract Rate
GBP Daily
driven integrations on AWS. Technical skills: - Front End: JavaScript, HTML; responsive UI patterns and web standards. - Back End: Node.js and Spring Boot microservices; RESTful API design and API management (policies, rate limiting, security), EKS (Kubernetes), Containerisation (Docker). - Proficient in Kubernetes & Containerisation of Applications - Docker - Integration: data … layer integration; event driven design with Kafka; NoSQL (MongoDB/DocumentDB). - Security: IDAM/IdP, SSO, RBAC, SSL/TLS, KMS (key management and envelope encryption patterns), Graph API. - Cloud operability: telemetry and logging on AWS; performance and availability monitoring. - Tooling & delivery: Jira, Confluence, GitHub, CI/ ...

Senior Backend Engineer (Telco Integration Lead) Golang

Hiring Organisation
Ventula Consulting Limited
Location
London, UK
Employment Type
Full-time
seeking a foundational engineer to own our single greatest strategic asset: our unique, privileged access to network-level intelligence via the GSMA CAMARA API standard. This is our right to win, and you will be the engineer responsible for building the bridge to it. You will be the Critical … build the Security Signal Ingestion path, the secure, low-latency, and out-of-band data channel connecting to our founding members' network API gateways. ? Architect and implement a carrier-agnostic, vendor-agnostic connector layer to consume RESTful APIs from a heterogeneous global landscape of telco partners and IMS vendors ...

Senior Backend Engineer (Telco Integration Lead) Golang

Hiring Organisation
Ventula Consulting Limited
Location
City of London, London, United Kingdom
Employment Type
Permanent, Work From Home
seeking a foundational engineer to own our single greatest strategic asset: our unique, privileged access to network-level intelligence via the GSMA CAMARA API standard. This is our right to win, and you will be the engineer responsible for building the bridge to it. You will be the Critical … build the Security Signal Ingestion path, the secure, low-latency, and out-of-band data channel connecting to our founding members' network API gateways. ? Architect and implement a carrier-agnostic, vendor-agnostic connector layer to consume RESTful APIs from a heterogeneous global landscape of telco partners and IMS vendors ...

Senior Backend Engineer - Systmes Design - Golang

Hiring Organisation
Ventula Consulting Limited
Location
City of London, London, United Kingdom
Employment Type
Permanent, Work From Home
seeking a foundational engineer to own our single greatest strategic asset: our unique, privileged access to network-level intelligence via the GSMA CAMARA API standard. This is our right to win, and you will be the engineer responsible for building the bridge to it. You will be the Critical … build the Security Signal Ingestion path, the secure, low-latency, and out-of-band data channel connecting to our founding members' network API gateways. Architect and implement a carrier-agnostic, vendor-agnostic connector layer to consume RESTful APIs from a heterogeneous global landscape of telco partners and IMS vendors ...

Senior Backend Engineer - Platform Security

Hiring Organisation
Ventula Consulting
Location
London, United Kingdom
Employment Type
Permanent
Salary
GBP 130,000 - 160,000 Annual
seeking a foundational engineer to own our single greatest strategic asset: our unique, privileged access to network-level intelligence via the GSMA CAMARA API standard. This is our right to win, and you will be the engineer responsible for building the bridge to it. You will be the Critical … build the Security Signal Ingestion path, the secure, low-latency, and out-of-band data channel connecting to our founding members' network API gateways. Architect and implement a carrier-agnostic, vendor-agnostic connector layer to consume RESTful APIs from a heterogeneous global landscape of telco partners and IMS vendors ...

Senior Full Stack Web Engineer - Trading

Hiring Organisation
Keyrock
Location
London, England, United Kingdom
assets. We're actively building it. Mission statement We are seeking a Full Stack Web Engineer with a strong sense of UI/UX design and a proven track record in the financial services industry. Experience in the crypto or digital asset domain is highly valued. You will work … consistent operational hygiene through clear documentation, smooth migrations, and predictable deployments. Explore and share emerging technologies, with particular interest in Rust, WebAssembly, and modern API frameworks. Background And Experience Proven experience building full stack web applications with strong command of both frontend and backend principles. Proficiency in modern frontend ...

Senior Full Stack Web Engineer - Crypto

Hiring Organisation
Keyrock
Location
City Of London, England, United Kingdom
assets. We're actively building it. Mission statement We are seeking a Full Stack Web Engineer with a strong sense of UI/UX design and a proven track record in the financial services industry. Experience in the crypto or digital asset domain is highly valued. You will work … consistent operational hygiene through clear documentation, smooth migrations, and predictable deployments. Explore and share emerging technologies, with particular interest in Rust, WebAssembly, and modern API frameworks. Background And Experience Proven experience building full stack web applications with strong command of both frontend and backend principles. Proficiency in modern frontend ...

Front End React Developer

Hiring Organisation
Ascend Consulting
Location
North West London, London, England, United Kingdom
Employment Type
Full-Time
Salary
£40,000 - £80,000 per annum
will coordinate with the rest of the team working on different layers of the infrastructure. Therefore, a commitment to collaborative problem solving, sophisticated design, and quality product is important. Responsibilities Working in a team of Front-End engineers Writing clear & concise code Working closely with Back-End engineers Participate … architecture design code reviews API design with the Back-End engineers and other team members to establish more functional, cohesive code Create, maintain documentation while implementing the best coding practices standards Hands-on approach Participation in sprint rituals What you’ll need 6+ years experience developing large ...

Principal Full Stack Engineer React, C#, AWS

Hiring Organisation
Smart Sourcer Limited
Location
City of London, London, United Kingdom
Employment Type
Permanent
Service (PaaS) environment. What Youll Be Doing: Own architecture and technical decisions across squads; accountable for how software is built and shipped. Design and develop distributed, scalable microservices (C# .NET Core or Node.js) and REST/JSON APIs. Build modern React + TypeScript UIs with component-driven design, advanced state management, and reusable frameworks. Leverage AWS services (Lambda, API Gateway, SQS/SNS, Step Functions, S3, IAM) to deliver secure, event-driven systems. Embed testing-first practices (TDD/BDD, contract tests, Jest/RTL, Playwright/Cypress, xUnit/NUnit) to raise code quality. Implement ...

Head of Development and AI

Hiring Organisation
McCabe & Barton
Location
City of London, London, United Kingdom
Employment Type
Permanent
engineering background with proficiency in Python, JavaScript/TypeScript, Java, or Go Experience with modern frameworks (React, Node.js, Django, FastAPI) Knowledge of microservices architecture, API design (REST, GraphQL) Experience with containerization (Docker, Kubernetes) and cloud-native development patterns DevOps & SRE Practices Experience implementing CI/CD pipelines ...

Senior Back End Engineer (.NET/Azure)

Hiring Organisation
E-Solutions IT Services UK Ltd
Location
Central London, London, England, United Kingdom
Employment Type
Contractor
Contract Rate
Salary negotiable
client mortgage journey. We’re looking for an experienced engineer who combines deep .NET and Azure expertise with a collaborative, pragmatic mindset. You’ll design and implement the backend services, APIs, and integrations that power our lending ecosystem, while working closely with front-end, product, and infrastructure teams. This … engineering principles. You’ll be part of a team where architectural thinking, reliability, and craftsmanship are valued just as much as delivery speed. Responsibilities Design, build, and maintain backend services using C# (.NET 8+) and Azure Services. Develop and secure Modern Distributed Systems using Azure Container Apps, integrating with ...

Technical Lead - FinTech ScaleUp

Hiring Organisation
Bondaval
Location
City Of London, England, United Kingdom
GoCardless, Skyscanner). The Role: Technical Lead We are looking for a Technical Lead to join our high-calibre software engineering team. You will design, build, and maintain the core services and APIs that power our proprietary platform, with opportunities to contribute to both back-end and front … next evolution of our platform, designing architecture, managing engineers and shaping how we integrate AI and large language models into our products and workflows. Design, implement, and maintain scalable back-end services and APIs (primarily in Go, with Python for scripting and data). Mentor and manage team members ...

Core Engineer - DeFi - London (F/M/D)

Hiring Organisation
Flowdesk
Location
London, England, United Kingdom
truth and a scalable platform for business units to leverage. We're hiring a Core Engineer to join the team and help lead the design and delivery of a new internal platform. Mission Be a key player in the newly formed Core Engineering team at Flowdesk to build … event streams for downstream consumers; maintain backward compatibility and schema evolution. Ways of working Follow established architecture and coding standards; participate in RFCs/design reviews and propose incremental improvements within existing patterns. Write clean, well-documented code and meaningful tests. Contribute to PR reviews; maintain up-to-date ...

Gen AI Developer

Hiring Organisation
PA Consulting
Location
London, England, United Kingdom
fine tuning LLM models, knowledge graphs, chain of thought prompting, and to contribute to platforms that are scalable to global scale. Responsibilities: Software Development: Design and build high-quality, highly reliable software solutions. Develop and implement AI/ML models with a focus on Generative AI, using open source … with AI development methods Solid understanding of distributed systems and system architecture. Experienced in building and running micro-services at scale. Knowledge of RESTful API design and implementation. Development experience with at least one public cloud provider (e.g., AWS, Azure, Google Cloud). Programming Languages: Proficiency in Python ...

Solution Architect

Hiring Organisation
Henderson Scott
Location
North West London, London, United Kingdom
Employment Type
Permanent
Salary
£75,000
Pension, Support Leave Salary: £70,000 - £75,000 Per Annum. Overview A key role within the Technology function, responsible for shaping solution design for a major business programme. You'll ensure solutions align with architectural standards, support integration and reporting platforms, and work closely with engineering teams and suppliers … deliver high-quality, scalable, and secure outcomes. Key Responsibilities Lead solution design across major programme workstreams, aligning with architectural vision and technical standards. Support cloud and data governance; define best practice for integration and reporting. Maintain and enforce standards for API design, integration patterns, data schemas (including ...

Python Developers Needed - DV/SC Cleared - Amazing Company

Hiring Organisation
Areti Group | B Corp™
Location
London Area, United Kingdom
preference. 2+ years experience in backend or full-stack software development Strong skills in Python, with exposure to JavaScript/TypeScript Experience with API design, microservices, and cloud deployments Solid understanding of software engineering best practices A passion for clean, maintainable code and performance Experience working in high ...

Machine Learning Software Engineer, Research

Hiring Organisation
PhysicsX
Location
City Of London, England, United Kingdom
enabling high-fidelity, multi-physics simulation through AI inference across the entire engineering lifecycle, PhysicsX unlocks new levels of optimization and automation in design, manufacturing, and operations — empowering engineers to push the boundaries of possibility. Our customers include leading innovators in Aerospace & Defense, Materials, Energy, Semiconductors, and Automotive. Note … Will Do Work closely with our research scientists and simulation engineers to build and deliver models that address real-world physics and engineering problems. Design, build and optimise machine learning models with a focus on scalability and efficiency in our application domain. Transform prototype model implementations to robust ...

Senior PHP Developer

Hiring Organisation
Gallagher
Location
London, England, United Kingdom
broader reuse across the platform. Uphold and contribute to platform-wide engineering standards, including secure coding, error handling, and performance optimisation. Collaborate on API design and domain modelling for new services and platform extensions. Support CI/CD workflows and contribute to containerised deployment processes using Docker … guidance to mid-level and junior developers within the team. Stay abreast of Symfony ecosystem updates and relevant advancements in PHP, cloud-native design, and scalable backend patterns. About You Background working on a productised platform or multi-tenant system serving multiple clients. Experience integrating with third-party systems ...