26 to 42 of 42 API Design Jobs in London

owning the cloud-native platform that underpins conversational AI and generative AI products at scale. Sitting at the core of AI delivery, you will design, build, and operate the runtime, infrastructure, and operational layers supporting RAG pipelines, LLM orchestration, vector search, and evaluation workflows across AWS and Databricks. Working … platform powering conversational assistants and generative AI products. Build, operate, and optimise RAG and LLM-backed services, improving latency, reliability, and cost. Design and run cloud-native AI services across AWS and Databricks, including ingestion and embedding pipelines. Scale and operate vector search infrastructure (Weaviate, OpenSearch, Algolia, AWS Bedrock ...

full-stack product delivery, from infrastructure and AI integrations through to React/React Native interfaces, collaborating closely with founders, creators, product, and design to turn lean specs into scalable, user-loved software. We’re looking for a strong generalist with backend depth and real mobile experience. Responsibilities Implement … mobile + web frontend → APIs → data models → integrations) while maintaining quality and velocity. Build React Native mobile apps and shared component systems across products. Design and ship scalable backend services (APIs, integrations, AI workflows). Run tight build → test → iterate → ship loops; provide realistic estimates and surface blockers early. ...

seasoned technical leaders. What matters is how you think, build, and ship. You'll take end-to-end ownership of features from architecture design to measurable impact — shipping code that directly moves revenue, retention, or product velocity. You'll design clean abstractions in ambiguous environments, evolve systems into … . We care about outcomes, not activity. What We're Looking For You've built and shipped real systems. You understand data modelling, API design, system trade-offs, testing, and reliability. You know how to move fast without creating chaos. You're strong in at least one modern ...

senior individual-contributor role within a high-performing engineering team, building asynchronous, message-driven systems designed for scale, resilience, and near-zero downtime. Design and implement high-throughput, low-latency systems processing millions of real-time payment events Build event-driven architectures using modern Java and reactive frameworks Work … extensively with non-blocking I/O, asynchronous flows, back-pressure, and concurrency Contribute to system and API design, focusing on scalability, fault tolerance, and observability Collaborate closely with architects, engineers, and client teams across Europe Operate in Agile environments (Scrum/Kanban) with a strong engineering culture ...

Start Up - Smart Living Platform Fully Remote - Must be UK based £85,000 - £95,000 + Stock Options (DOE) Essential Exp: Laravel, Flutter, SaaS, API Design, MySQL/PostgreSQL/MariaDB G.R.E. Recruitment is DELIGHTED and EXCITED to partner with an exciting UK based PropTech Start-Up company … defining technical standards, scalability strategy, and product direction across the technical ecosystem. In this role you will: Own and evolve a Laravel-based REST API Develop and maintain a Flutter mobile application (iOS & Android) Design and implement secure, multi-tenant architecture Establish clean coding standards and engineering best ...

develop new features, enhance existing systems, and ensure our platform remains stable and efficient. Your deep understanding of Rails architecture, PostgreSQL optimisation, and API design will be essential as you contribute to ongoing development projects. If you enjoy collaborating in Agile/Scrum environments, value clean code ...

evolution of core Ruby on Rails operational platforms. Optimise PostgreSQL performance and Sidekiq background job efficiency. Manage secure third-party integrations and RESTful API design. Partner with Platform teams on AWS and CI/CD reliability. The Person: Deep experience with Ruby on Rails and OOP. Expert in PostgreSQL ...

architectural direction, influencing engineering standards, and shaping the evolution of AI-enabled capabilities across the mobile platform. In this role, you will: Lead the design, development, and maintenance of advanced iOS applications, ensuring high performance, quality, and responsiveness across Expedia Group’s product suite. Architect and implement robust, scalable … system and API designs, including effective data modelling to support complex business requirements. Drive cross-functional collaboration to define, develop, and ship impactful features, ensuring alignment with organisational goals and technical strategy. Champion best practices in software engineering, testability, and maintainability through code reviews and mentoring. Safely integrate ...

ensuring solutions are secure, scalable and aligned with the organisation's long-term technology strategy. Key Responsibilities Define and govern technical architecture standards and design principles Provide hands-on architectural leadership across cloud platforms, integrations and development Lead architecture reviews and technical design decisions Support engineering teams with … Senior Developer Strong experience with Microsoft Azure cloud platforms Experience working with Dynamics 365/CRM environments Knowledge of cloud architecture, integrations and API design Familiarity with DevOps and modern engineering practices Strong communication skills and ability to engage both technical and non-technical stakeholders Benefits Salary ...

. What you’ll be doing: Own end-to-end product slices: frontend UX, backend APIs, data models, integrations, and operational reliability. Lead technical design, propose trade-offs, and set engineering patterns for the team. Build fast, robust AI-assisted workflows handling streaming, async jobs, and complex state management. … pairing, coaching, and high-signal code reviews. Tech stack & experience: Frontend: TypeScript + React/Next.js. Backend: Python (FastAPI or similar), async/concurrency, API design, operational readiness. Databases: Postgres, data modeling, migrations, query optimization. SaaS authentication & permissions: OIDC/OAuth, JWT, RBAC/ABAC. Applied AI experience ...

platform used by clients, operations teams and field contractors across the UK. You will work across Python and Django on the backend, contributing to API design, system architecture and end to end feature delivery. The environment includes modern web technologies such as React and HTMX, supported ...

influence architectural decisions at a critical stage of growth. The Backend Engineer (Full Stack, backend-leaning) will take ownership of complex backend REST API Services and deliver scalable systems using TypeScript and Node.js . You will closely with Product, Engineering and Operations, working alongside the Lead Engineer to refine … technical direction, improve delivery standards and elevate system reliability. The Senior Backend Engineer (Full Stack, backend-leaning) will... • Design and maintain scalable Node.js/TypeScript services and REST APIs • Own backend initiatives end-to-end, from architecture to rollout • Strengthen testing strategy across unit and integration layers • Improve data ...

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 ...

operations teams and field contractors across the UK. You will work on modern web applications using Python, Django, HTML, HTMX and React, contributing to API design, system architecture and end to end feature delivery. This is a high ownership role suited to someone comfortable working autonomously ...

share code with iOS. You’ll be joining a collaborative engineering group working on major new features, shaping technical discussions, influencing architecture and API design, and helping to evolve a category-defining product used across the UK, US and several new international markets launching in 2026. What they ...

Start Up - Smart Living Platform Fully Remote - Must be UK based £85,000 - £95,000 + Stock Options (DOE) Essential Exp: Laravel, Flutter, SaaS, API Design, MySQL/PostgreSQL/MariaDB G.R.E. Recruitment is DELIGHTED and EXCITED to partner with an exciting UK based PropTech Start-Up company ...

typical frontend role. You’ll be working at the heart of a graphics and visualisation engine — solving problems around rendering, performance, correctness, and API design. Why engineers take this role You work on the hard stuff This is core library engineering: rendering engines, chart primitives, 2D graphics, and public … Strong JavaScript and/or TypeScript fundamentals Experience with 2D graphics (Canvas, SVG, Processing, or similar) Solid grounding in data structures, algorithms, and software design Experience with at least one statically typed language Working understanding of basic linear algebra Apply in confidence. Company details shared at first conversation. ...