26 to 50 of 289 API Design Jobs in London

Senior Software Engineer – Customer Order

Hiring Organisation
Jobleads-UK
Location
Greater London, England, United Kingdom
Design, build, and evolve backend services that support the complete customer order lifecycle, from order creation through to fulfilment and completion. Develop scalable microservices and APIs using Java/Kotlin, enabling reliable and efficient order processing across multiple channels. Contribute to event-driven architectures using Kafka to support high … volume transactional workflows across Payments, Pricing, and Fulfilment domains. Design and evolve GraphQL and REST APIs, ensuring consistency, performance, scalability, and an excellent developer experience. Build resilient, low-latency solutions using distributed databases, caching technologies, and modern architectural patterns. Collaborate closely with Product Managers, Engineers, Architects, and business stakeholders ...

Backend Developer (Azure)

Hiring Organisation
Amtis Professional Ltd
Location
London, Euston, United Kingdom
Employment Type
Contract
Contract Rate
£425 - £475/day OUTSIDE IR35
outside IR35. This is a hands-on role working on a mature Azure-based backend platform, with responsibility across the full software lifecycle - from design and development through to testing, deployment and production support. You’ll be working with C#, .NET, Azure Functions, Azure SQL, Azure Service Bus, Azure … API Management and Azure DevOps, contributing to a platform that supports connected patient services. This role is particularly suited to a developer who can hit the ground running, work independently and own technical delivery end-to-end without requiring day-to-day technical supervision. What You’ll Be Doing ...

Backend Developer (Azure)

Hiring Organisation
Amtis professional Ltd
Location
London, South East England, United Kingdom
Employment Type
Full-Time
Salary
£425.00 - £475.00 per day
outside IR35. This is a hands-on role working on a mature Azure-based backend platform, with responsibility across the full software lifecycle - from design and development through to testing, deployment and production support. You’ll be working with C#, .NET, Azure Functions, Azure SQL, Azure Service Bus, Azure … API Management and Azure DevOps, contributing to a platform that supports connected patient services. This role is particularly suited to a developer who can hit the ground running, work independently and own technical delivery end-to-end without requiring day-to-day technical supervision. What You’ll Be Doing ...

Software Development Engineer II

Hiring Organisation
Expedia
Location
London, United Kingdom
Salary
£ 80 K
great experience to delight our customers. Our goal is to enhance every traveler's experience and make it better!In this role, you will:Design, develop, and maintain high-throughput, low-latency distributed backend services that deliver efficient, optimal pricing solutions at scale.Implement robust caching mechanisms to enhance application … performance, reduce latency, and optimize resource utilization.Participate in system design, API design, and data modeling for scalable, reliable microservices.Contribute to technical documentation, detailed code reviews, and architecture discussions to ensure high-quality solutions.Analyze complex problems, break them down into manageable milestones, and collaborate with cross-functional teams ...

Software Development Engineer II

Hiring Organisation
Jobleads-UK
Location
Greater London, England, United Kingdom
great experience to delight our customers. Our goal is to enhance every traveler's experience and make it better! In this role, you will: Design, develop, and maintain high-throughput, low-latency distributed backend services that deliver efficient, optimal pricing solutions at scale. Implement robust caching mechanisms to enhance … application performance, reduce latency, and optimize resource utilization. Participate in system design, API design, and data modeling for scalable, reliable microservices. Contribute to technical documentation, detailed code reviews, and architecture discussions to ensure high-quality solutions. Analyze complex problems, break them down into manageable milestones, and collaborate ...

Front Office C# Senior Developer - VP

Hiring Organisation
Barclays
Location
East London, London, United Kingdom
Employment Type
Permanent, Work From Home
Salary
GBP per day
experience (Solace or similar like Kafka/RabbitMQ) Backend focus with UI-awareness for BFF interaction Must Have C# Real time data/streaming API design experience Server side development experience (threading, memory management, performance) Desirable K8S AI/LLM experience (e.g. Claude, Codex, Agents and Agentic flow … Multitude of functions to support UI interaction for pricing Pricing blotter support Adapt messages to proprietary Pricing Engine format sent and received over Solace API design to be flexible reuse where possible for curve construction for Rates, FX, and other problem domains About Barclays Barclays is a British ...

Senior Python Engineer – AI Agents, Forecasting

Hiring Organisation
Jobleads-UK
Location
Greater London, England, United Kingdom
LangChain or LangGraph (agent memory, tool calling, state management) Dagster in production (assets, sensors, partitions) or equivalent pipeline orchestration Strong backend fundamentals including API design, async programming, and database modelling You've built systems that had to work reliably at scale, not just pass a demo Worked … signal resume keywords Production-Grade Python Development LLM Orchestration Frameworks Dagster Pipeline Orchestration Backend Fundamentals AWS Infrastructure Experience ATS Optimization Keywords Hard Skills Python API Design Async Programming Database Modelling Random Forests Regression Models Scikit-Learn PyTorch Mathematics Statistics Soft Skills Holistic Thinking Research-Driven Problem Solving Leadership ...

Product Manager – Global Card Issuing Platform (BaaS)

Hiring Organisation
WorldFirst
Location
London, United Kingdom
Salary
£ 80 K
grade infrastructure that allows clients to launch card programs anywhere in the world through a single integration.You will be responsible for a unified Global API and SDK suite that abstracts the complexity of regional payment networks. Whether a client is launching in Europe, North America, or APAC, your product … will provide a consistent, white-label experience. You will drive both the technical "how" (API/SDK design) and the strategic "where" (global expansion and regional issuing setups).What you’ll do:Unified Global API Strategy: Design and maintain a single, polymorphic API architecture that ...

Software Engineer - Core Networking

Hiring Organisation
Jobleads-UK
Location
Greater London, England, United Kingdom
part of influencing the strategic direction for connectivity with Neo4j and the drivers together with our product managers. You will be leading the design of new features and improvements to the protocol whilst taking on feedback from other experts and stakeholders within the company. You will then implement these … interest in: Network development (binary protocol specs like Bolt , Frontend/Backend , MongoDB Wire Protocol ) Network packet analysis (e.g., Wireshark) Distributed system design API design Netty Customer experience and developer community interaction Concurrency and asynchronous programming You may have also worked with some of: Database management systems ...

backend developer for developer documentation

Hiring Organisation
Jobleads-UK
Location
Greater London, England, United Kingdom
code reviews, pair programming, and architecture discussions; Collaborate cross-functionally with other Apple teams to integrate tools and systems seamlessly; Write detailed architecture and design proposals; Identify areas for continuous improvement; Mentor other engineers; Contribute to architecture discussions, code reviews, and proposals. Требования Experience shipping high-quality, performant … reliable web applications; Passion for developing products and features; Ability to discuss technical trade-offs across system architecture, database design, API design, and infrastructure; Continuous learning attitude focused on improving personal and team capabilities; Nice to have: BS/MS in Computer Science, Computer Engineering, Informatics ...

Product Lead, EMEA Payments

Hiring Organisation
Stripe
Location
London, United Kingdom
Salary
£ 80 K
behind critical payment flows across EMEA.ResponsibilitiesDefine a multi-year vision for EMEA Payments that anticipates future merchant and ecosystem scale and complexityLead Engineering and Design through every phase of the product lifecycle, from 0-to-1 development to General AvailabilityEnforce rigorous standards for product quality, API design … related product roleA track record of shipping technical B2B2C products at a high velocityAn obsession with product quality in all its forms—from API design to dashboard UX and documentationExisting knowledge of the payments landscape or a demonstrated ability to learn complex domains quicklyStrong written and verbal communication ...

Full Stack Engineer (Contract Role)

Hiring Organisation
Jobleads-UK
Location
Greater London, England, United Kingdom
work alongside architects, product stakeholders and delivery partners to ship software that brokers and analysts use every day. Key Responsibilities Build Across the Stack: Design, build and ship features end to end, from APIs and services through to responsive, accessible user interfaces. Cloud Native Delivery: Develop and run cloud … usable, performant ways for brokers and analysts. AI‐Enabled Development: Build AI‐enabled product features using patterns such as retrieval‐augmented generation, tool and API integration, evaluation and human‐in‐the‐loop design. AI‐Assisted Engineering: Use AI‐assisted engineering tools such as Claude Code or Claude Cowork ...

Java API Developer, Assistant Vice President

Hiring Organisation
State Street Bank
Location
London, United Kingdom
Salary
£ 80 K
DescriptionRole Summary :We are seeking an experienced Java API Developer to join our Digital Asset development team. This is a hands‐on engineering role responsible for building and operating secure, resilient API services that power institutional digital asset capabilities—spanning digital custody, tokenization enablement, digital transfer agency … will work closely with cross-functional teams to build robust, scalable, and secure digital asset products that meet our business and technical requirements.Role Description:Design, develop, and maintain Java backend services and REST APIs that support digital asset product flows (custody, tokenization, TA, digital cash/settlement) and integrate ...

Full Stack Engineer

Hiring Organisation
Jobleads-UK
Location
Greater London, England, United Kingdom
work alongside architects, product stakeholders and delivery partners to ship software that brokers and analysts use every day.**Key Responsibilities:*** **Build Across the Stack:** Design, build and ship features end to end, from APIs and services through to responsive, accessible user interfaces.* **Cloud Native Delivery:** Develop and run cloud … usable, performant ways for brokers and analysts.* **AI-Enabled Development:** Build AI-enabled product features using patterns such as retrieval-augmented generation, tool and API integration, evaluation and human-in-the-loop design.* **AI-Assisted Engineering:** Use AI-assisted engineering tools such as Claude Code or Claude Cowork ...

Senior Software Engineer, Tech Lead (Full Stack)

Hiring Organisation
Jobleads-UK
Location
Greater London, England, United Kingdom
when: technical approach, task breakdown, sequencing, capacity, and the quality bar, and be accountable for delivery; Hold the line on backend design discipline, so that services stay maintainable as the team and codebase grow; Collaborate with Product, Design, and QA to define, design, and ship features, distinguishing … Tech Lead or in a similar technical-Leadership role, owning a team's technical approach and delivery; Strong backend fundamentals: Clean Architecture, design patterns, and API design, with hands-on experience in C#/.NETor Node/TypeScript; Proven experience building single-page web apps with React ...

Staff Software Engineer

Hiring Organisation
BP
Location
London, United Kingdom
Salary
£ 80 K
value as well as achieving our carbon net-zero goals.As an engineer on this project, you will collaborate with Product Managers and partners to design, develop and maintain enterprise scale software systems and tools.As part of a global team working on a global product, you will lead … distributed production systems.Passionate about mentoring and coaching engineers across both technical and soft skills.Product-centric mentality with the ability to understand business needs and design scalable, resilient systems and solutions.Strong empathy and curiosity to create exceptional user experiences.Self-starter with excellent communication skills, adept at handling ambiguity, navigating uncertainty ...

Senior Developer - Azure Applications

Hiring Organisation
Jobleads-UK
Location
Greater London, England, United Kingdom
BDSthe company helps organisations deliver meaningful digital transformation through cloud, data, AI and cyber security. We work across the public and private sector to design and build technology solutions that make a genuine difference to users. We’re looking for an Azure Application Developer with strong API development … production ready solutions within Microsoft Azure. The RoleAs an Senior Developer at UBDS, you’ll work alongside developers, architects, DevOps and security engineers to design and build cloud native applications and APIs. This is a hands on role where you’ll take solutions from requirements and design through ...

Corporate Solutions Engineer, UK

Hiring Organisation
Jobleads-UK
Location
Greater London, England, United Kingdom
company is the world’s leading API platform, used by more than 45 million+ developers and 500,000 organizations, including 98% of the Fortune 500. the company is helping developers and professionals across the globe build the API-first world by simplifying each step of the API … Partners, and Nexus Venture Partners. Learn more at the company.com or connect with the company on X via ----- P.S: We highly recommend reading The "API-First World" graphic novel to understand the bigger picture and our vision at the company. Account Strategy Lead technical discovery sessions to uncover customer ...

Principal Enterprise Architect

Hiring Organisation
Jobleads-UK
Location
Bromley, England, United Kingdom
enterprise and partner ecosystems. The position also plays a key role in shaping industry best practices and representing the organisation externally. Enterprise & Ecosystem Architecture Design and oversee the implementation of enterprise‐wide software architecture, spanning internal platforms, cloud environments, and external partner ecosystems Develop “big picture” architectural frameworks … adherence to security, compliance, regulatory, and quality standards Identify and mitigate long‐term architectural risks (e.g., vendor lock‐in, scalability constraints, regulatory exposure) Technical Design & Solution Development Conduct research, analyse data, gather requirements, and define end‐to‐end solutions Create architectural artefacts representing system functions, integrations, and user interfaces ...

Staff Product Manager - API Connectivity

Hiring Organisation
ebury
Location
London, United Kingdom
Salary
£ 80 K
operate globally, get in touch - we’d love to discuss how Ebury can accelerate your career so you can shape the future.Staff Product Manager - API ConnectivityProduct Ebury London Office - Hybrid: 4 days in the office, 1 day working from home per weekWe are looking for an experienced Product Manager … API Connectivity with ERP and accounting platforms. This role will lead the strategy, delivery, and evolution of integrations with systems such as Sage, QuickBooks, and ERP aggregators (e.g. Codat, Merge, Apideck).You will be responsible for building scalable, high-quality integrations that power financial workflows for our partners ...

Senior Software Engineer, Inference Platform

Hiring Organisation
Jobleads-UK
Location
Greater London, England, United Kingdom
after you’re helping with UI/UX, customer success, documentation and product ops. What You’ll Do Inference Platform Architecture & Core Services Design and build the company's inference service platform the backbone for serving AI models at scale across diverse workloads Own and architect core platform components … Gateway, Resource Orchestrator, Runtime Engines, and Autoscaler Design highly modular, scalable, and extensible low‐level designs (LLDs) for inference infrastructure components Lead high‐level design discussions, establish architectural patterns, and drive technical decision‐making for the inference stack Model Deployment & Lifecycle Management Understand and optimize the dynamics ...

Senior Java Developer

Hiring Organisation
CODEVERSE LIMITED
Location
London, South East England, United Kingdom
Employment Type
Full-Time
Salary
£300.00 - £400.00 per day
experienced Senior Java/Python Engineer to join a high-performing Agile engineering team delivering secure, highly available and scalable microservices and API platforms. You will be hands-on with modern engineering technologies, working across microservices, APIs, Kafka, cloud databases, containers and observability, while also providing technical leadership … mentoring junior engineers. Key Responsibilities Design and develop scalable Java/Python microservices and REST APIs. Build and operate event-driven solutions using Apache Kafka . Design and optimise AWS Aurora PostgreSQL databases and data platforms. Deploy and support applications using Docker and Kubernetes . Develop API ...

Java API Developer, Officer

Hiring Organisation
State Street Bank
Location
London, United Kingdom
Salary
£ 80 K
Role Summary :We are seeking a Java API Developer to join our Digital Asset development team. This is a hands-on software engineering role responsible for designing, developing, testing, and supporting RESTful APIs and backend services in a financial services environment. The role contributes to building reliable, secure … will work closely with cross-functional teams to build robust, scalable, and secure digital asset products that meet our business and technical requirements.Role Description :Design, develop, and maintain Java-based backend services and REST APIs that support financial services workflows and data use cases.Implement APIs in line with internal ...

Python Technical Lead FinTech

Hiring Organisation
Run-Time Group Ltd
Location
City of London, London, United Kingdom
Employment Type
Permanent
major advantage. Key Responsibilities Technical Leadership Own the technical roadmap, guide architectural decisions, and ensure engineering excellence across backend services. Python Engineering Design and build robust, secure, and scalable microservices using Python (FastAPI, Django, Flask). System Architecture Lead the design of distributed systems, event-driven architectures … data intelligence. DevOps & Cloud Collaborate on CI/CD pipelines, containerisation (Docker, Kubernetes), and cloud deployments (AWS/GCP/Azure). Data & API Strategy Oversee API design, data modelling, and integration with internal and external financial systems. Security & Compliance Ensure systems meet regulatory, security, and audit ...

Senior Full Stack/Native Cloud Engineer (Vice President)

Hiring Organisation
Jefferies Financial Group
Location
London, United Kingdom
Salary
£ 100 K
full technology stack, from backend services and distributed data architecture through to responsive user interfaces, production support, and engineering best practice.Key ResponsibilitiesLead the design, development, and delivery of backend services and platform components using Java 8+/Spring Boot and Python/FastAPI. Build, enhance, and operate event-driven … real-time data pipelines using Kafka and related streaming technologies. Provide deep technical expertise in distributed systems, data architecture, and scalable platform design. Design, implement, and maintain Java-based APIs and microservices, including REST, OpenAPI, GraphQL, and gRPC services. Work with modern data technologies including PostgreSQL, MongoDB, and Amazon ...