26 to 50 of 52 API Design Jobs in London

Type: Full-time, Permanent About the Role We're looking for a Senior Software Engineer with deep experience in Python and AWS to help design, build, and scale distributed, data-driven Ad-Tech systems. You'll lead the delivery of cross-service features within a modern cloud platform, making … direction, mentoring engineers, and ensuring the systems you build are secure, observable, and resilient. Key Responsibilities Lead complex delivery: Drive the end-to-end design and implementation of Python-based microservices and cloud-native solutions hosted on AWS. Architect and optimise systems: Define service boundaries, data ownership, and failure ...

flow diagrams). Hands-on experience with major cloud platforms (preferably AWS), including Infrastructure as Code, networking, and security. Deep understanding of secure system design, authentication patterns, and observability. Familiarity with languages such as Ruby, Python, or Java, and modern practices (CI/CD, TDD, containerisation). Strong knowledge … data modelling, API design, and integration patterns. If you would like immediate consideration, please send me an updated CV/contact details to jcaria@redglobal.com so we can discuss further or reach out to me through LinkedIn. ...

work across: Advanced theme builds using Liquid Hydrogen, Oxygen and modern Shopify frameworks Custom Shopify app development (Node/React or Ruby) API development and third-party integrations Performance optimisation for high-traffic storefronts Building reusable frontend components and design systems Technical scoping and solution design Code … Shopify developer Proven background in building and maintaining custom Shopify apps Strong knowledge of Liquid, frontend fundamentals and Shopify's latest tooling Understanding of API design, data structures and integration patterns Experience working on large-scale or high-growth ecommerce brands Confident in leading technically and supporting developers ...

Familiar with different multi agent system patterns Build and deploy LLM-based solutions using RAG Familiar with different types of databases: Relational, Graph etc. Design and optimise APIs using Python and FastAPI to serve AI solutions. Familiar with GCP ecosystem and Cloudrun Build and optimise data pipelines for vector … Agentic architectures with ADK, LlamaIndex, or LangGraph. Working with vector databases for embedding and indexing. Strong experience with cloud platforms Strong experience with API design and frameworks like FastAPI or Flask Solid experience with relational databases and SQL Interest in expanding your knowledge into GenAI and machine learning ...

Core Skills: Minimum 4 years of hands-on experience with the Outsystems platform Strong understanding of Outsystems Architecture, including modularization, performance optimization, and scalable design principles. Professional Traditional Web Developer Certification (mandatory). Associate Developer (ODC) Certification (mandatory). Scripting languages such as JavaScript, TypeScript or NodeJS Strong .NET … Core (C#) skills (including Entity Framework and MVC and WebAPI, .NET 8 or later Additional Technical Experience: RESTful API design & integration Security and Architecture certifications are a strong plus. Familiarity with integration patterns (REST/SOAP APIs, external systems, and identity providers like Azure AD). ...

/LLM systems and their integration into applications. Experience with async programming and message queuing (e.g., Celery or equivalents). Strong understanding of API design and real-time data processing. Hands-on AWS experience (e.g., EC2, Lambda, ECS, RDS). Clear track record of shipping production features quickly. ...

What you will do: Architect Python backend systems (FastAPI, gRPC) and define technical standards Build complex APIs, data workflows, and external system integrations Lead design reviews, mentor engineers, and drive technical roadmap Productionise automation-generated code and workflow orchestration pipelines Collaborate with data platform, product and wider support teams … What you will need: 7+ years Python experience (FastAPI) Deep API design expertise (REST, gRPC) and SQL proficiency (PostgreSQL/MySQL) Track record building integrations (APIs) Experience owning a product end-to-end, and driving technical excellence Experience with CI/CD and cloud platforms (AWS/Azure ...

transformation. What You’ll Lead Technical Ownership Act as the senior developer and architect for all systems powering stores, production, POS, loyalty, and website. Design and implement SOA, ensuring all retail and e-commerce systems integrate cleanly and scale reliably. Own CIAM, security rules, and token management (OAuth2/… site or high-traffic environments,. 8+ years in development/architecture, including 3+ years of hands-on technical leadership. Deep understanding of SOA, API design, cloud platforms, networking, and distributed systems. Proven experience integrating POS, WMS, CRM, loyalty, or similar retail systems. Experience with Adobe Commerce, Salesforce ...

+ benefits/Bonus Join a leading financial technology and trading organisation driving innovation in electronic markets. As an eFX Software Engineer, you'll design and deliver high-performance, low-latency trading solutions that underpin mission-critical systems. This role offers the chance to work on cutting-edge technology … where speed, scalability, and resilience are key. About the Role Lead the design and development of secure, high-performance eFX systems Define and evolve Java patterns and techniques optimised for ultra-low latency (<40s) Architect fault-tolerant, scalable trading systems Influence technical strategy, architecture, and product roadmaps Collaborate with ...

customers. Small team. Big impact. Real engineering challenges. The role You’ll work across the backend platform powering key customer-facing experiences. You will: Design and build scalable backend services in Node.js + TypeScript Own systems end-to-end (architecture → deployment → monitoring) Develop APIs and platform components used across … multiple products Solve performance, reliability and observability challenges Ship iteratively with product + design Improve engineering quality and share knowledge If you enjoy autonomy and seeing your work hit production quickly, you’ll love this environment. What you’ll bring 5+ years of backend engineering experience Strong with Node.js ...

product strategy. Requirements: Strong foundations in algorithms, data structures, and distributed systems Experience building and operating large-scale backend systems Expertise in system and API design, scalability, and performance tuning Proficiency in a modern backend language (Java preferred) Knowledge of cloud-native architectures, containers, and CI/ ...

influencing product strategy.Requirements: Strong foundations in algorithms, data structures, and distributed systems Experience building and operating large-scale backend systems Expertise in system and API design, scalability, and performance tuning Proficiency in a modern backend language (Java preferred) Knowledge of cloud-native architectures, containers, and CI/ ...

accounting infrastructure that underpins Pleo's spend management solution. You will be the deep subject matter expert on accounting, transaction management, and external API capabilities, ensuring our platform is robust, scalable, and compliant. You will own the product direction for the systems responsible for processing and managing payment transaction … will: Bring deep subject-matter expertise in accounting, with a strong focus on payment transaction records, reconciliation flows, and financial data management Understand API fundamentals - particularly the requirements for exposing APIs externally - and ensure the platform enables seamless integrations for customers and partners Incorporate compliance and regulatory considerations relevant ...

designing high-performance architectures and distributed systems Strong grasp of FX pricing, risk, and trading workflows Solid engineering fundamentals: testing, CI/CD, API design, automation Why join? Work on mission-critical systems powering global trading Highly technical culture with genuine ownership and impact Flexibility in working hours ...

commercial software development experience. Proven success in high-performing engineering teams within fast-paced environments. Deep expertise in: Python (Django, Flask, or FastAPI) PostgreSQL (design, optimisation, maintenance) Containerisation (Docker/Kubernetes) Event-driven architecture (Kafka/RabbitMQ) Desirable experience includes: TypeScript/JavaScript (NextJS, NodeJS, Tailwind) Terraform and DevOps … practices Experience in building and scaling SaaS platforms in production. Strong background in software architecture, microservices, and API design. Hands-on experience with AWS platform. Excellent communication skills, capable of motivating and aligning technical teams. Experience with AI tools, APIs, or ML pipelines is highly desirable. Bonus: Exposure ...

commercial software development experience. Proven success in high-performing engineering teams within fast-paced environments. Deep expertise in: Python (Django, Flask, or FastAPI) PostgreSQL (design, optimisation, maintenance) Containerisation (Docker/Kubernetes) Event-driven architecture (Kafka/RabbitMQ) Desirable experience includes: TypeScript/JavaScript (NextJS, NodeJS, Tailwind) Terraform and DevOps … practices Experience in building and scaling SaaS platforms in production. Strong background in software architecture, microservices, and API design. Hands-on experience with AWS platform. Excellent communication skills, capable of motivating and aligning technical teams. Experience with AI tools, APIs, or ML pipelines is highly desirable. Bonus: Exposure ...

model, built to deliver expressive, high-fidelity video at unmatched speed. It powers both our own products and a growing ecosystem of partners through API integration. The company is also known globally for pioneering consumer creativity through products like Facetune, one of the world’s most recognized creative brands … which helped introduce AI-powered visual expression to hundreds of millions of users worldwide. We combine deep research, user-first design, and end-to-end execution from concept to final render, to bring the future of expression to all. Why Join Us We’re here to push the boundaries ...

opportunity to make a real impact in a rapidly growing team, while working on cutting-edge AI technology. What You'll Work On: Design and implement scalable backend systems using Python (FastAPI, Flask, or Django) Integrate AI-generated code into production-ready services Take ownership of projects from idea … agentic-coding workflows to accelerate development Who You Are: 5+ years of experience in back-end development (Python based stack ideally) Strong understanding of API design and systems architecture Strong communication and collaboration skills Exposure to AI, LLMs or modern ML-backed systems is a plus! Apply ...

finance or trading environment Hands-on experience with CFD, spread betting, or investment product development Confident using JIRA, Confluence, Figma, Miro Strong understanding of API design , agile practices, and release processes Proven ability to collaborate directly with engineering leadership Bonus Skills Familiarity with trading platform architecture or microservice ...

appropriate test coverage You are a Front-End specialist but you understand aspects of the full tech stack and can contribute meaningfully to API design and overall system architecture The Extras Working at Slice comes with a comprehensive set of benefits, but here are some of the unexpected ...

appropriate test coverage You are a Front-End specialist but you understand aspects of the full tech stack and can contribute meaningfully to API design and overall system architecture The Extras Working at Slice comes with a comprehensive set of benefits, but here are some of the unexpected ...

build innovative products Evaluate, appropriately test, and debug your work, striving for high quality Knowledge, Skills & Abilities: Strong knowledge in C++ Strong understanding of API design Ability to independently execute on medium sized features, taking a few weeks and multiple PRs to complete Ability to understand, debug ...

leading global investment management firm in London. Paying up to 120k plus bonus per annum, you will contribute to the development, optimisation, and design of front-office applications, collaborating with portfolio managers and product owners to create innovative and high-performance solutions. As a Senior Full Stack Software Engineer …/UX. Proven backend expertise, particularly with Java (Python, Node.js a plus), and experience building distributed microservices-based architectures. Strong knowledge of system design principles, scalable architecture patterns, and API design. Hands-on experience with relational (Postgres, MySQL) and NoSQL (DynamoDB) databases. Proficiency in cloud platforms (AWS, Azure ...

details Rely on data and customer feedback to guide decisions and prioritise effectively Being able to go into the details of API design, payment messages or whatever is required Are passionate about developing people and creating an inclusive, collaborative team environment Enjoy working in a fast-paced, constantly ...

mitigate risks associated with migration and system cutover. Core Skills & Experience: Proven expertise in PAS systems and complex data migration projects. Strong knowledge of API design and integration . Advanced data modelling skills for structured and semi-structured data. Proficiency in XML, JSON, and Excel for data handling ...