1 to 25 of 42 Remote/Hybrid API Design Jobs in London

Principal Engineer - Technical Lead (Gen AI and MACH Architecture)

Hiring Organisation
Jobleads-UK
Location
Greater London, England, United Kingdom
believe in the imaginative application of art and science to create beautiful ideas, products and services. With an entrepreneurial and collaborative approach, we design and build adaptive digital products, services and experiences that capture the imagination and deliver impressive returns for our clients. We are looking for a senior … technical leadership, architecture and team guidance. You will lead the technical direction of complex client programmes across MACH architectures and production Generative AI; spanning Design to Code workflows, solution design and API contracts through to cloud infrastructure, deployment and ongoing operation. You will own architecture decisions, write ...

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 + Benefits Join a newly formed Service Modernisation & AI team driving AI-first software … 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 Strong TDD experience Java/Microservices/API design/LLMs/AI/Claude Code/Copilot ...

Enterprise Architect

Hiring Organisation
Jobleads-UK
Location
Greater London, England, United Kingdom
govern the architecture of the Digital Backbone – the foundational layer that connects systems, data, and services across the enterprise – while driving adoption of API-first principles, integration best practices, and enterprise-wide governance.The Digital Backbone is Howden Group's foundational technology and integration layer, designed to eliminate fragmented systems … manual processes, and to enable digital product delivery and innovation at scale. **WHAT WILL YOU BE DOING?** ## Architecture Leadership & Design* Define, own, and communicate the enterprise architecture of the Digital Backbone, establishing it as the strategic integration platform across Howden Group.* Architect and lead the design, development ...

Enterprise Architect

Hiring Organisation
Jobleads-UK
Location
City Of London, England, United Kingdom
core integration and technology platform, shaping and governing the foundational layer that connects systems, data, and services across the enterprise. Responsibilities Architecture Leadership & Design Define, own, and communicate the enterprise architecture of the Digital Backbone. Architect and lead the design, development, and deployment of APIs and integrations, ensuring … alignment with standards and strategic goals. Drive adoption of API‐first design principles and the APIOps methodology, including automation of API deployment and governance. Develop, maintain, and communicate key architecture artefacts such as policies, standards, principles, patterns, templates, and capability models. Manage Group Enterprise Architecture assets – application ...

Senior Software Engineer

Hiring Organisation
Jobleads-UK
Location
Greater London, England, United Kingdom
Full Stack Engineer with a strong back‐end focus to join one of our Profile domain product teams. This role is full stack by design: you will work across back‐end and front‐end codebases, contributing to end‐to‐end product delivery. However, your primary strength will … front end. You will join an established, autonomous product team owning their product end‐to‐end, with real ownership over technical design, implementation, and continuous improvement. Your responsibilities Design, build and evolve scalable back-end services using C# and .NET Core, alongside developing front-end features with modern ...

Senior Software Engineer

Hiring Organisation
Stepstone UK
Location
South East London, London, United Kingdom
Employment Type
Permanent
Full Stack Engineer with a strong back-end focus to join one of our Profile domain product teams. This role is full stack by design: you will work across back-end and front-end codebases, contributing to end-to-end product delivery. However, your primary strength will … front end. You will join an established, autonomous product team owning their product end-to-end, with real ownership over technical design, implementation, and continuous improvement. Your responsibilities Design, build and evolve scalable back-end services using C# and .NET Core, alongside developing front-end features with modern ...

Technical Lead (Golang)| 1 year | London, UK (Hybrid - 3 days/week in office)

Hiring Organisation
Hamilton Barnes
Location
London, United Kingdom
Employment Type
Contract
Contract Rate
GBP 550 Daily
Lead (Golang)| 1 year | London, UK (Hybrid - 3 days/week in office) We're recruiting for an experienced Technical Lead to lead the design, development, and delivery of enterprise-scale cloud-native applications using Golang, Microservices Architecture, and Azure Cloud technologies for a leading organisation. The role requires … mentoring capabilities to drive high-quality software delivery while ensuring scalability, reliability, security, and operational excellence across multiple Agile teams. Key Responsibilities Lead the design, development, and delivery of enterprise-scale applications across Agile teams Provide technical leadership, architectural direction, and engineering best practices to development teams Design ...

Senior Software Engineer

Hiring Organisation
Jobleads-UK
Location
Greater London, England, United Kingdom
play a key part in driving the adoption of AI across engineering, leveraging emerging technologies and embedding AI-native workflows to improve how we design, build, and deliver software. This role is predominantly hands‐on, with around 20–30% of time on technical leadership: architecture, mentoring, and shaping … generated code to our standards for security, reliability, and cost-efficiency (FinOps). These are first-class concerns in agentic pipelines, not afterthoughts. Design, build, and operate software across our platform, applying the same rigor to AI-augmented work as to anything else you ship. Embed deeply with Product ...

Python Application Developer with DevOps

Hiring Organisation
Jobleads-UK
Location
Greater London, England, United Kingdom
environment Qualifications Hands-on experience in production environments as a Software Developer and DevOps/Platform Engineer Strong production experience with Python and software design patterns (SOLID, DRY) Expertise in AWS (or similar cloud providers), Containerization and Kubernetes Deep understanding of RESTful API or GraphQL API design ...

Python Application Developer with DevOps

Hiring Organisation
Jobleads-UK
Location
City Of London, England, United Kingdom
team? Hands-on experience in production environments as a Software Developer and DevOps/Platform Engineer Strong production experience with Python and software design patterns (SOLID, DRY) Expertise in AWS (or similar cloud providers), Containerization and Kubernetes Deep understanding of RESTful API or GraphQL API design ...

Senior Engineer - PayE

Hiring Organisation
Jobleads-UK
Location
Greater London, England, United Kingdom
development of our next-generation platform channels. Partner on the delivery of new products while continuously maintaining and improving existing ones. Architecture & Design: Collaborate with team members and engineering leaders to design new services and components utilizing our internal Request for Comments (RFC) process. End-to-End Ownership … Frontends (MFEs) is a major plus. DevOps & Cloud: Hands-on experience with Docker, Kubernetes, Terraform , and AWS . Foundations: Strong understanding of system architecture, API design, scalable service integration, Linux systems, and Git version control. Core Soft Skills: Strong knowledge of basic algorithms, object-oriented/functional design ...

Senior Backend Engineer - UK

Hiring Organisation
Jobleads-UK
Location
Greater London, England, United Kingdom
startup with experience building SaaS products. You will also have a deep understanding of the key challenges engineers face and a firm grasp on design principles in prioritizing key features and capabilities. Your superpower is how to bridge the gap between technical specifics and business needs effortlessly and turn … engineering mastermind behind Heidi developing AI products which will change the face of healthcare Autonomously deliver beautiful & robust code with considerations on code structure design and scalability. Implement and optimize data storage solutions. Design, build, and maintain high-performance backend systems using Python. Architect and manage cloud infrastructure ...

Backend Engineer

Hiring Organisation
Robert Half Limited
Location
London, United Kingdom
Employment Type
Contract, Work From Home
systems that enable global commerce, while evolving an existing real-time platform to support new markets. You will address backend capacity constraints and help design a shared transaction and ledger layer used across multiple business lines. This is a hands-on senior engineering role requiring both high-quality delivery … strong technical leadership in ambiguous, high-scale environments. You will be expected to: Design scalable systems with correctness and failure modes considered from the outset Clarify and scope requirements before proposing solutions Make pragmatic trade-offs in system design, avoiding over-engineering Operate independently without reliance ...

Principal Developer

Hiring Organisation
Jobleads-UK
Location
Greater London, England, United Kingdom
delivery methodology to ensure timely and high-quality delivery of software applications. Technical Ownership: Take technical ownership of a product or software solution, covering design, estimation, shaping, and user story/requirement creation. Solution Documentation: Document solutions, including architecture, configuration, release, and support handover. Stakeholder Collaboration: Collaborate and liaise … practices and modern architectural patterns, including microservices and message-driven architectures. Non-Functional Requirements: Experience developing applications with non-functional requirements in mind. Application Design: Experience in application/digital services design. Software Engineering Practices: Proficiency in software engineering practices like code reviews, CI/CD pipelines, and SOLID ...

Developer Enablement, Technical Architect – Release on Demand (SVP)

Hiring Organisation
Jobleads-UK
Location
Greater London, England, United Kingdom
built to last and built to scale. Drive Scalability & Reliability. Lead the engineering effort to make RoD elastically scalable and enterprise-grade reliable. Design for high availability, graceful degradation, and zero-downtime deployments. Define SLOs, own the SRE practice for the platform, and be accountable when things need fixing. … fully understood at all times. You will set the standard and ensure the team can operate with confidence. Establish End-to-End Testing. Design and champion a robust E2E testing strategy across the platform. From contract testing at service boundaries to full integration and regression suites, you will ensure ...

Senior Engineer

Hiring Organisation
Jobleads-UK
Location
Greater London, England, United Kingdom
Treasury foundation that can scale with us. 🎯 Your Responsibilities in this Role Own key architecture and implementation decisions for the collections & treasury foundation Lead design work (RFCs, diagrams, API and system specs) to align on solutions before building Partner with PMs and stakeholders to translate business intent into … technically sound requirements Design and build customer-facing and internal APIs to support collections and payment strategies Build reliable infrastructure for vIBAN provisioning and collections orchestration Drive engineering quality across API standards, testing strategy, code review bar, and maintainability Manage delivery by breaking down complex work, sequencing milestones ...

Engineering Manager | Payments, Abuse, and Conversion

Hiring Organisation
Jobleads-UK
Location
Greater London, England, United Kingdom
depth in fraud prevention, abuse detection, rate limiting, or bot protection to guide architectural decisions across a complex, multi‐layered fraud stack. Distributed systems design: Proven experience designing, building, and operating scalable, highly available distributed systems in a cloud‐native environment. Modern tech stack experience: Demonstrable experience with cloud … platforms (preferably AWS), containerisation (Docker, Kubernetes), and API design (gRPC, REST). Database expertise: Hands‐on experience with both relational and NoSQL databases. A people‐first approach: Deep commitment to the growth and well‐being of your team, with proven experience in coaching, mentorship, and performance management. Commercial ...

Senior Product Engineer

Hiring Organisation
Jobleads-UK
Location
Greater London, England, United Kingdom
contexts Use customer feedback, analytics, and direct user insights to inform technical decisions, prioritise improvements, and validate that shipped features deliver measurable value Design and implement complex data flows, API integrations, and background processing systems that handle high-volume operations reliably while maintaining system performance and data integrity … Partner with product, design, and customers to shape solutions early, translating business requirements into technical architecture while surfacing risks and opportunities that impact customer outcomes Mentor and coach other engineers, raising the bar for technical excellence through code reviews, pair programming, and architectural guidance Beyond the tech ...

Senior Full Stack Java Developer

Hiring Organisation
Hackajob Ltd
Location
South West London, London, United Kingdom
Employment Type
Permanent, Work From Home
Salary
£85,000
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 Version … 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 ...

Senior C# Engineer .NET 9, AWS Lambda, SQS, SNS Outside IR35

Hiring Organisation
Smart Sourcer Limited
Location
City of London, London, United Kingdom
Employment Type
Contract
Contract Rate
From £700 to £800 per day
Overview: Youll operate as the technical spearhead for a greenfield product build, reporting to the Director of Engineering. Expect deep backend engineering, distributed system design, and high-quality serverless delivery, plus the chance to adopt modern AI-assisted development practices as part of your workflow. What Youll Bring: Senior … ability to architect and lead distributed REST microservices at scale. Strong authority in AWS serverless engineering: Lambda-first mindset, hands-on experience with API Gateway, SQS, Step Functions, EventBridge and IAM. Deep data expertise across Aurora MySQL and DynamoDB: schema design, access patterns, indexing, query tuning, and pragmatic ...

AI Native Engineer

Hiring Organisation
Jobleads-UK
Location
Greater London, England, United Kingdom
centres already operating at 100% whole slide image scanning capacity in Geneva and Lausanne. Core Responsibilities Core Agentic Architecture & Retrospective Extraction LLM Extraction Agents: Design, build, and maintain production-grade LLM-based extraction pipelines to automatically parse years of unstructured PDF pathology reports. Structured Parsing: Programmatically extract clinical entities … biomarker statuses from raw, free-text documents. Framework Selection: Evaluate and integrate specialized agentic frameworks and orchestration tooling (e.g., LangChain, LlamaIndex, or direct LLM API implementations) based on measurable extraction accuracy against real-world clinical text, rather than what is fashionable. Confidence Scoring & Human-Review Loops: Build programmatic confidence ...

C# .Net Developer

Hiring Organisation
Pontoon
Location
Bromley, Kent, England, United Kingdom
Employment Type
Contractor
Contract Rate
£700 - £750 per day
Chicago). The role offers the opportunity to contribute to business-critical systems while working in a collaborative and supportive environment. Key Responsibilities Design, develop, enhance, and maintain enterprise applications using C# and .NET technologies. Support and improve existing business-critical systems, ensuring stability, performance, and scalability. Work closely … with business users, analysts, and technical teams to gather requirements and deliver solutions. Participate in the full software development lifecycle, including design, development, testing, deployment, and support. Collaborate with globally distributed development teams across multiple locations and time zones. Contribute to technical discussions, solution design, code reviews ...

C# .NET Developer

Hiring Organisation
Pontoon
Location
Bromley, London, South Yorkshire, United Kingdom
Employment Type
Contract
Contract Rate
£650 - £750/day Inside IR35
Chicago). The role offers the opportunity to contribute to business-critical systems while working in a collaborative and supportive environment. Key Responsibilities Design, develop, enhance, and maintain enterprise applications using C# and .NET technologies. Support and improve existing business-critical systems, ensuring stability, performance, and scalability. Work closely … with business users, analysts, and technical teams to gather requirements and deliver solutions. Participate in the full software development lifecycle, including design, development, testing, deployment, and support. Collaborate with globally distributed development teams across multiple locations and time zones. Contribute to technical discussions, solution design, code reviews ...

Senior Backend Python Engineer

Hiring Organisation
Interact Consulting Limited
Location
South West London, London, United Kingdom
Employment Type
Permanent, Work From Home
What were looking for: Hands-on experience running real production workloads on AWS not just deploying to it Strong Postgres/SQL skills: schema design, query tuning, migrations Solid API design chops: clear contracts, versioning, backwards compatibility Python-first mindset (FastAPI or similar) Redis experience: caching patterns ...

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 ...