26 to 50 of 51 API Design Jobs in London

Senior AI Engineer

Hiring Organisation
Appcast
Location
London, UK
Consultant) to join our Technology Delivery team. In this role, you’ll combine deep expertise in AI/ML engineering and software development to design, build, and deploy advanced generative AI and agentic systems for leading financial services clients. You’ll work hands-on across the full AI engineering … experience deploying LLMs and multi-modal AI models within enterprise or large-scale production environmentsStrong software engineering expertise in Python, including backend development, API design, and distributed systemsSolid understanding of scalable MLOps, observability, CI/CD practices, and cloud-native AI deployment architecturesExcellent communication, stakeholder management, and problem ...

Senior Application Security Engineer / DevSecOps Engineer

Hiring Organisation
Additional Resources
Location
London, United Kingdom
Employment Type
Permanent
Salary
£80000 - £90000/annum
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. ...

Contract AI Software Engineer - DV Cleared

Hiring Organisation
NSD
Location
City of London, London, United Kingdom
Employment Type
Contract, Work From Home
Contract Rate
£450 - £650 per day
Experience with AWS or Azure Familiarity with Docker and Kubernetes Experience working in secure or highly regulated environments Strong understanding of software architecture and API design IT WOULD BE NICE FOR THE AI SOFTWARE ENGINEER TO HAVE. Experience with RAG pipelines and vector databases Knowledge of MLOps tooling ...

Senior Software Engineer

Hiring Organisation
XCEEDANCE LIMITED
Location
London Area, United Kingdom
skilled Java Software Engineer with a growing interest and demonstrated exposure to AI/ML integration. This role is primarily Java-centric — you will design and build cloud-native microservices on our BPA (Beyond Policy Administration) platform — with the expectation that you actively apply AI tooling and patterns … prototype level. Role Details Location: London Experience: 4–7 years of overall software engineering experience Engagement Model: Full-time, Product Engineering Job Responsibilities Design and implement RESTful APIs and microservices using Java 17+ and Spring Boot 3.x. Build and maintain business logic within the BPA platform, ensuring correctness, performance ...

Net Developer

Hiring Organisation
Pontoon
Location
Bromley, London, United Kingdom
Employment Type
Contract
Contract Rate
£700 - £750/day
Develop and maintain high-quality software applications using .NET (4.5+/.NET Core) and Python. Collaborate with cross-functional teams to gather requirements and design effective solutions. Provide support to team members and stakeholders to ensure smooth project execution. Liaise with technical and business colleagues to understand functional requirements … deliver solutions that align with business objectives. Utilise your understanding of Web Services (REST, SOAP) to design and document APIs effectively. Work with MS SQL Server, including TSQL, SSIS, SSRS for database management and reporting. Utilise version control tools such as Git/Bitbucket and job scheduling tools like ...

Senior Software Engineer – Data Visualisation & Graphics | London

Hiring Organisation
techstack Recruitment
Location
City of London, London, United Kingdom
working on the underlying systems that make complex visualisations fast, accurate, and scalable. The challenges range from rendering performance and interaction design through to algorithms, graphics, API design, and numerical correctness. What you’ll be doing Designing and building core charting features used by developers around … exceptionally high technical standards High levels of ownership and autonomy Small team, significant impact Opportunity to deepen expertise in performance, graphics, visualisation, and systems design Package Salary up to £200,000 Hybrid working (London) Private healthcare Pension Additional benefits If you’re interested in building the technology behind modern ...

Mobile Engineer

Hiring Organisation
Appcast
Location
London, UK
running a business.Teya exists to change that.We’re building a financial platform for local businesses across Europe - one built around simple tools, thoughtful design and real human support. Our Members rely on us to help them run their business with confidence, and that responsibility shapes the way we work.We … friendly experience for merchants across Europe.Collaborate with cross-functional teams to align technical solutions with business objectives.Actively participate in critical project decisions, including architecture design, framework selection, and tool evaluation.Mentor and support team members, fostering a collaborative and growth-oriented environment.Continuously improve applications while applying automation best practices ...

Senior Full-Stack Engineer, North Tools & Retrieval

Hiring Organisation
Appcast
Location
London, UK
senior generalist who can move freely across backend and frontend as the roadmap demands. You will pick up any layer of a feature, from API design and database schema to the frontend that sits on top of it, and own it end-to-end.In this role, you will … Design, build, ship, and maintain features across the full stack for our roadmap surfaces: large-scale file upload and management, shared knowledge bases, the agent extensibility framework (skills and integrations), and the pipeline that syncs external enterprise data into the platform.Own features end-to-end, from technical design ...

Principal Software Architect

Hiring Organisation
Spectrum IT Recruitment
Location
Uxbridge, London, United Kingdom
Employment Type
Permanent
Salary
£100000 - £120000/annum
models and integration patterns Reviewing significant technical initiatives and providing architectural guidance across multiple engineering teams Embedding security, resilience, scalability and observability into platform design from the outset Identifying architectural risk, technical debt and platform constraints Partnering with Engineering and Product leadership on strategic technical decisions Influencing engineering teams … experience defining architecture across SaaS, product-led or platform-based environments Experience working across complex, multi-system or distributed technology landscapes Strong understanding of API design, integration architecture and service-oriented systems Cloud architecture experience, ideally within Azure A strong appreciation for security-by-design, resilience, scalability ...

Integration Architect

Hiring Organisation
i3
Location
City of London, London, United Kingdom
plus bonus and benefits City of London Hybrid An experienced Enterprise Integration Architect with deep London Market insurance knowledge who can design, govern, and modernise complex integrations between insurance systems, Lloyd's platforms, brokers, bureaus, and partners while ensuring security, resilience, and scalability. My client is looking for someone … design and lead the messaging technology that allows the exchange of data securely and reliably with external organisations , particularly within the London Market and Lloyd's insurance ecosystem . The ideal candidate: an experienced integration architect with 8+ years designing enterprise integration solutions. Lloyd's, bureau messaging, bordereaux, delegated ...

Engineering Lead - Xplan

Hiring Organisation
Experis UK
Location
City of London, London, United Kingdom
role in shaping the future technology landscape supporting advisers and clients across the organisation. The Role As Engineering Lead, you'll own the design, development, integration and operation of the firm's financial planning platform, ensuring it remains scalable, secure and fit for future growth. You'll provide technical … Experience Strong experience with iRESS Xplan , including configuration, customisation and integration. Proven leadership experience within software engineering or platform engineering environments. Strong understanding of API design and enterprise integration patterns. Experience delivering solutions within regulated financial services environments. Knowledge of cloud and middleware technologies, including serverless architectures. Experience ...

Solution Architect - Azure Services, API, HLD/LLD

Hiring Organisation
Fusion People
Location
London, United Kingdom
Employment Type
Permanent
Salary
GBP 85,000 - 95,000 Annual
architectural function from scratch and a transformation modernization. You will report into the Head of Architecture and work closely with architects across domains to design (HLD, LLD) and deliver scalable solutions and end to end integration solutions in marketing, security, finance, data, product, archiving, document management amongst others. Essential … projects Although a solution architect role, a good understanding of enterprise architecture principals Solution integration technology - experience designing integration solutions across enterprise applications. API design, messaging patterns, and integration architectures. Experience with security architecture, data protection, relational databases (SQL Server) and data integration patterns. Nice to have: Experience ...

S/4HANA - Coupa Integration Architect

Hiring Organisation
CBSbutler Holdings Limited
Location
London, United Kingdom
Employment Type
Contract
Contract Rate
Up to £558 per day + inside ir35
between Coupa and SAP S/4HANA. This is an opportunity to work on a high-profile global programme, owning integration architecture from initial design through to deployment, cutover and Hypercare. What you'll be doing: Designing and delivering Coupa SAP S/4HANA integrations across complex enterprise landscapes … Leading integration architecture, solution design and technical delivery Building and managing APIs including REST/JSON, OData, IDocs and BAPIs Supporting procurement process integrations covering: Supplier and Business Partner data Purchase Orders Goods Receipts Service Entry Sheets Invoices and payment status updates Master data synchronisation Working with integration platforms ...

Android Engineer- Regional Experience

Hiring Organisation
Wise
Location
Greater London, United Kingdom
Employment Type
Full Time
Salary
68000 to 87500 GBP Annually
verification, through to receiving, sending, and spending money. We're looking for engineers who want to take initiative, collaborate directly with product and design, and work on the highest impact projects across all of our markets. You'll have the opportunity to help shape the engineering culture … modern app architectures like Unidirectional Data Flow, Dependency Injection, Structured Concurrency with Kotlin Coroutines, amongst others Desire to write testable code Understanding of REST API design Strong product mindset and passion for user experience, with a focus on prioritising work that addresses user needs and making data-driven ...

Senior Product Manager / Head of Product

Hiring Organisation
Sanderson
Location
City of London, London, United Kingdom
vertical, evolving it from a standalone capability into a scalable platform proposition Lead expansion into new acceptance channels and emerging adjacent sectors.] Own API strategy and enablement, ensuring seamless integration with partner technologies and external devices. Develop the vision and roadmap for a key new vertical, shifting from … within Card Present/In-Person Payments Experience owning and scaling payment APIs and third-party integrations Ability to engage in technical discussions around API design, integrations and hardware/software interactions Proven track record identifying product-market fit and expanding into new verticals Experience operating within Agile ...

Applied AI Engineer

Hiring Organisation
Tenth Revolution Group
Location
London, South East, England, United Kingdom
Employment Type
Full-Time
Salary
£150,000 - £190,000 per annum
concept and production-grade AI solutions. Architect, develop and deploy AI-native applications leveraging Large Language Models (LLMs), agentic systems and multimodal AI technologies. Design, build and orchestrate intelligent agent workflows using the Gemini Enterprise Agent Platform, Agent Development Kit (ADK) and Agent2Agent (A2A) protocol. Develop and implement Retrieval … using modern front-end technologies such as React, Next.js and Svelte. Build robust backend services, APIs and orchestration frameworks to support AI-powered applications. Design and manage data architectures across SQL, NoSQL and vector database environments. Collaborate with business stakeholders to identify, prioritise and deliver AI use cases that ...

iOS Software Engineer

Hiring Organisation
Burton Recruitment
Location
London, South East, England, United Kingdom
Employment Type
Full-Time
Salary
£70,000 - £100,000 per annum
performance, reliability, and user trust are critical. Build and maintain iOS applications using Swift and SwiftUI. Integrate AI-powered features through backend APIs. Design UX patterns for AI interactions, including loading states, streaming responses, retries, and fallbacks. Optimize performance, memory usage, and battery efficiency. Capture user signals and feedback … support AI evaluation and iteration. Collaborate closely with backend and ML engineers on API design and system behavior. Maintain high App Store quality, stability, and production reliability. Requirements: 3+ years of iOS development experience using Swift. Hands-on experience integrating AI-powered features into mobile apps. Strong understanding ...

Software Developer

Hiring Organisation
Randstad Technologies
Location
London, South East, England, United Kingdom
Employment Type
Contractor
Contract Rate
£559 - £600 per day
Basel III/IV, CCAR, counterparty limit monitoring, or live exposure calculations. Core Tech Stack: Expert-level C#/.NET (.NET Core), scalable API design, and solid OOP/architectural principles. Data & High Performance: Strong SQL skills, experience handling large data volumes, and working with event-driven/ ...

Software Developer (233204-1)

Hiring Organisation
Randstad Technologies
Location
London, South East, England, United Kingdom
Employment Type
Contractor
Contract Rate
£600 - £700 per day
Basel III/IV, CCAR, counterparty limit monitoring, or live exposure calculations. Core Tech Stack: Expert-level C#/.NET (.NET Core), scalable API design, and solid OOP/architectural principles. Data & High Performance: Strong SQL skills, experience handling large data volumes, and working with event-driven/ ...

Java / Scala Developer

Hiring Organisation
Appcast
Location
London, UK
something you are passionate about.The Java Scala developer will be involved in:Web application greenfield developmentWeb analytics & business intelligenceMachine learning, risk modelling, fraud detection.API design and provisionIntegration patterns & messagingHybrid cloud infrastructureJavaScript application developmentWeb application performanceScalabilityExceptional knowledge of low-high level systems coupled with true programming ability.Java Scala Developers MUST ...

Junior Java / Scala Developer Fintech

Hiring Organisation
Appcast
Location
London, UK
passionate about.The Junior Java Scala developer will be involved in:Web application greenfield developmentWeb analytics & business intelligenceMachine learning, risk modelling, fraud detection.API design and provisionIntegration patterns & messagingHybrid cloud infrastructureJavaScript application developmentWeb application performanceScalabilityExceptional knowledge of low-high level systems coupled with true programming ability.Junior Java Scala Developers MUST have ...

Cloud Engineer

Hiring Organisation
Anson McCade
Location
City of London, London, United Kingdom
technology organisation delivering mission-critical systems that support national security and help protect the UK. Working as part of empowered DevOps teams, you'll design, develop, deploy and maintain cloud-based applications and services, collaborating with engineers and end users to solve complex technical challenges. The Role … opportunity to work with cutting-edge cloud technologies, contribute to innovative solutions and continue developing your skills within a supportive engineering community. Key Responsibilities •Design, develop and maintain secure cloud solutions using AWS. •Build and support applications and services across AWS environments. •Work within agile DevOps teams to deliver ...

Java & React Engineer

Hiring Organisation
Randstad Technologies Recruitment
Location
City of London, London, United Kingdom
Employment Type
Permanent
Salary
£60000 - £70000/annum Market Rate/ Negotiable
Role: We are seeking an experienced Full-Stack Engineer (5-7 years) to join a leading global financial institution in London. You will design, build, and maintain high-performance, cloud-native applications supporting critical financial operations. Key Responsibilities: Design and deliver end-to-end applications using Java (Spring … proficiency in Java, Spring Boot, and ReactJS . Hands-on experience with AWS, Kubernetes, and Kafka . Strong grasp of multithreading, microservices architecture, and API design. Financial services, Investment Banking, or Risk domain experience is highly advantageous. Ability to work from the London office 3 days per week . ...

Senior Data & Integration Architect

Hiring Organisation
Appcast
Location
London, UK
requires clear ownership of data, well-defined integration patterns, and controlled transitions between systems. The Senior Data & Integration Architect provides the architectural leadership to design these flows, define boundaries, and ensure that the service can operate reliably throughout this evolution.Role PurposeThe Senior Data & Integration Architect is responsible for defining … platform teamsEnsure architectural consistency across domains and delivery streamsRequired ExperienceSenior-level experience in solution architecture with strong focus on:Data architectureSystem integration and API designComplex application landscapesExperience in large-scale transformation programs, such as:Service transitionsCarve-outs or M&A environmentsMulti-platform coexistence scenariosSolid understanding of:Data ownership ...

Solution Architect - Integration - Salesforce

Hiring Organisation
SR2
Location
London, United Kingdom
Employment Type
Contract
Contract Rate
£650 - £750/day
drive architectural decisions will be essential. Responsibilities Define and maintain the end-to-end solution architecture across the rewards portal and wider Salesforce ecosystem. Design integration patterns across Salesforce, customer identity, APIs, mobile applications and enterprise platforms. Translate business and technical requirements into scalable, resilient and maintainable solution designs. … Define the architecture for SSO, customer identity integration and associated authentication journeys. Review and assure API designs, data flows, integration components and system dependencies. Support the design of mobile and in-app webview customer experiences. Produce architecture artefacts, solution options, design decisions and technical roadmaps. Coordinate suppliers ...