26 to 50 of 55 API Design Jobs in London

Senior AI Engineer

Hiring Organisation
Capco
Location
London, UK
Employment Type
Full-time
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 ...

Lead ETRM Solutions Architect

Hiring Organisation
Appcast
Location
London, UK
solutions. The ideal candidate is a hands-on architect who can define target state architecture, guide engineering teams, and drive best practices across system design, integration patterns, and platform strategy.Responsibilities:Define and own the architecture for applications and services across the end-to-end commodities trade lifecycle.Lead the design … resiliency, including monitoring, alerting, automated controls, reconciliation frameworks, and reprocessing capabilities.Govern architecture decisions with a focus on performance, scalability, maintainability, security, and cost efficiency.Lead design reviews and provide technical direction to engineering teams, promoting strong engineering standards, reusable patterns, and consistent integration approaches.Drive adoption of modern SDLC and platform ...

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. ...

Director, Forward Deployed Engineering

Hiring Organisation
Scale AI
Location
London, UK
Employment Type
Full-time
lead a team of elite engineers who embed directly with Fortune 500 customers to ship deeply integrated AI agents—owning everything from agent design and evaluation to the backend services, data systems, and cloud infrastructure that make them production-ready. You'll partner closely with our Forward Deployed … volume for senior engineering roles.Hands-on fluency with the full AI stack. Deep familiarity with LLMs and agent systems, evaluation frameworks, backend and API design (Python or TypeScript), data systems (PostgreSQL, DynamoDB, MongoDB, or similar), and cloud infrastructure (AWS, Azure, or GCP) including Kubernetes, Docker, and IaC tooling.Experience ...

UI Senior Lead Software Engineer - Commodities

Hiring Organisation
Hackajob Ltd
Location
South West London, London, United Kingdom
Employment Type
Permanent
inclusive team culture. This role emphasizes engineering excellence, operational readiness, and secure, compliant delivery in a fast-paced global environment. Job Responsibilities Lead the design and delivery of user interface capabilities across Execute, from discovery to production support Set front-end technical direction, including architecture, standards, performance, and testing … leadership in setting standards, leading designs, and directly managing or mentoring small teams of mid-level engineers Solid software engineering fundamentals, including OO/design patterns, debugging, and documentation Familiarity with agentic development approaches across the software development lifecycle Strong communication and people skills, with the ability to work ...

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 ...

AI Infrastructure Engineer, Sandbox Platform

Hiring Organisation
Scale AI
Location
London, UK
Employment Type
Full-time
teams to understand how they use the platform, debug their issues, and shape a roadmap that balances immediate needs with long-term architecture.You will:Design and build the sandboxing platform, client library, and API surface for secure code execution across containerized and virtualized environmentsEnsure strong isolation, security … maintain a product roadmap for sandboxing, balancing immediate needs against long-term architectural investmentLead architecture reviews and own projects end-to-end, from design through deployment, in fast-paced cross-functional settingsIdeally you'd have:4+ years of experience building high-performance systems software, with meaningful time spent maintaining ...

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 ...

Senior iOS Engineer

Hiring Organisation
Appcast
Location
London, UK
quality by writing unit and UI tests and contributing to the health of our CI/CD pipelines.Collaborate cross-functionally with Backend Engineers on API design, Product Managers on roadmap priorities, and Designers on seamless user experiences.What makes you great for this positionStrong proficiency in Swift and deep … knowledge of the iOS framework (Objective-C knowledge is a plus).Solid understanding of RESTful API integration and experience working with backend engineers on API design.Experience working with agile methodologies, CI/CD pipelines, and pair programming.Deep care for user interaction, usability, and interface quality—you build things ...

AI Engineer

Hiring Organisation
Oscar Associates (UK) Limited
Location
London, United Kingdom
Employment Type
Permanent
Hybrid Build the AI systems our users actually experience. We're looking for a dynamic AI Engineer (5+ years) to design, build, and deploy autonomous, user-facing AI solutions - LLM-powered applications, agentic workflows, and intelligent systems that perform reliably at scale, not just in a demo. What … Degree in Computer Science (or equivalent) with strong AI/ML/NLP foundations Strong Python skills, familiarity with Java/Kotlin, and solid API design experience Hands-on experience with LangChain, LangGraph, and LLM APIs (OpenAI, Anthropic, etc.) Skilled in prompt engineering and orchestrating AI agents/ ...

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 ...

AI & Agentic Technical Delivery Lead

Hiring Organisation
Appcast
Location
London, UK
AIWe AreAccenture Song accelerates growth and value for our clients through sustained customer relevance. Our capabilities span ideation to execution: growth, product and experience design; technology and experience platforms; creative, media and marketing strategy; and campaign, content and channel orchestration. With strong client relationships and deep industry expertise … edge cases, and real consequences when something went wrong.You have led engineering teams — hands-on enough to review a pull request and challenge a design decision, senior enough to set the technical direction and make it stick. You know how development teams work from the inside, which means ...

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 ...

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 ...

Knowledge Graph Consultant

Hiring Organisation
NTT DATA
Location
London, UK
Employment Type
Full-time
Graph ArchitectExperience: 10+ years (5+ years in Knowledge Graphs/Ontology Engineering)Role OverviewWe are looking for a Knowledge Graph Architect to lead the design and governance of enterprise knowledge graphs. This role will define the ontology, data model, and canonical vs. interpretive boundaries, enabling scalable, high-quality graph … prioritization, and skill developmentStakeholder CollaborationPartner with data, AI/ML, and business teamsTranslate requirements into semantic modelsProvide thought leadership on graph adoptionRequired SkillsNeo4j Schema Design (Cypher, property graph modeling)Ontology Engineering (OWL/RDF, Protégé)Graph RAG (LLM integration, retrieval strategies)API Design (REST/GraphQL)Preferred ...

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 ...

Fullstack Engineer, Scale

Hiring Organisation
Airwallex
Location
London, UK
Employment Type
Full-time
business, regulatory, and technical domains—areas where no single existing team has full coverage, like tax systems, compliance-driven flows, or monetization tools.Solutions Architecture: Design integrations for enterprise prospects by translating their business requirements into technical solutions. Your architectural decisions directly influence deal outcomes—from enabling multi-million dollar … technical stakeholdersMake pragmatic decisions on when to optimize for performance vs. velocity based on business impactThrive in cross-functional environments spanning Product, Design, Compliance, and SalesDesign for scale, maintainability, and production excellencePreferred qualifications: Fintech, payments, or regulated industry experienceHigh-scale performance tuning (100k+ QPS, large user bases, strict latency ...

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 ...

Agentic Platform Consultant

Hiring Organisation
NTT DATA
Location
London, UK
Employment Type
Full-time
Platform LeadExperience: 10+ years (5+ years in AI/LLM platforms, RAG, or agentic systems)Role OverviewWe are seeking an Agentic Platform Lead to design and deliver the consumption layer for AI agents, defining how agents query, interpret, and interact with knowledge graphs and enterprise data.This role will focus … agent workflowsTeam LeadershipLead a team of AI and platform engineersDemonstrate strong capability in coaching, mentoring, and leading internal teamsProvide hands-on technical guidance and design reviewsBuild a high-performing, collaborative team cultureDrive delivery, prioritization, and skill developmentStakeholder CollaborationPartner with AI/ML, data, and business teamsTranslate requirements into agent ...

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 ...

Quantitative Analyst (Rates Electronic Market Making)

Hiring Organisation
Citigroup
Location
London, UK
Employment Type
Full-time
trading spaceExtensive programming experience.Technology/programming skills in Rust, C++, Java, KDB, Python, SQLExtensive experience in messaging and data serialization technologies, market data processing, API design, latency optimization, code testing, build and deployment toolsExperience in taking ownership of existing technologies, building new ones, and performing technology migrations.Working knowledge ...

Vice President, Full-Stack Engineer

Hiring Organisation
Hackajob Ltd
Location
South West London, London, United Kingdom
Employment Type
Permanent
deployment, observability, and reliability. Raise engineering excellence and resilience: best practices and automation across code, testing, microservices/APIs, performance, and infrastructure; secure-by-design with threat modeling, logging/monitoring, incident playbooks, and disaster recovery. Partner with product, design, and operations to translate outcomes into measurable technical … building distributed systems and microservices in agile environments (Scrum/Kanban). Deep Java experience (Spring), architectural patterns for scalable, observable, testable systems; strong API design. Strong DevOps practices: CI/CD (e.g., GitLab), automated testing (JUnit/Spock), code reviews, telemetry/observability (Splunk, AppDynamics), containers (Docker ...

Core IP Security Software Engineer

Hiring Organisation
G Research
Location
London, UK
Employment Type
Full-time
detection and scanning tools.As a Software Engineer, you will take ownership of designing, developing and operating these systems across service backends, cryptographic libraries, API integrations and hardened infrastructure. The software you build must meet the highest standards of correctness, auditability and availability.You will work on both new capabilities … following skills and experience:Essential:Strong experience delivering production-quality software, ideally using C#/.NETStrong understanding of software architecture, concurrency, distributed systems and API designExperience building or operating security-sensitive systems where correctness and auditability are criticalSound engineering judgement, balancing security, performance, reliability and deliveryClear communication skills ...