426 to 450 of 455 API Design Jobs

Engineering London, UK or Ljubljana, Slovenia SDK Engineer

Location
Greater London, England, United Kingdom
binary size, startup cost, thread safety, and backward compatibility are the job, not afterthoughts. You will own what you build end to end, from API design through release and live integration support. Based in-office (hybrid model) in London or Ljubljana, Slovenia. You Will Build and maintain … mobile SDK on Android (Kotlin) or iOS (Swift) Own the public API surface: minimal, stable across versions, and hard to misuse Keep the SDK lightweight and resilient, with no crashes in host apps and graceful degradation when the backend is unreachable Own releases, versioning, and distribution (Maven Central, SwiftPM ...

Senior Backend Engineer - Payments Platform Leader

Location
Easthampstead, England, United Kingdom
across markets with a tight-knit team and direct access to product, compliance, and operations. You will own end-to-end backend delivery, from API design to production reliability, while advancing a modern stack with AI-assisted tooling. We seek a senior back-end engineer with 6–10+ … years of production experience, strong C#/.NET skills, and a track record in system design and leadership. #J-18808-Ljbffr ...

Independent Software Engineer: Build Practical Tools

Location
United Kingdom
Sygneus is seeking a Software Engineer to design, build, and maintain scalable systems and automation tools across internal and customer-facing platforms. You will contribute to architecture decisions and work closely with commercial and operational users to deliver practical solutions. The role rewards independence and rapid iteration, with ownership … development from API design to deployment, aligning technical outputs with real market needs and driving measurable value. #J-18808-Ljbffr ...

React Native Engineer

Location
Greater London, England, United Kingdom
with customer requirements and business objectives. Daily Tasks To contribute to Agile Scrum, and ensure deadlines and production quality. To spearhead creative solutions for API and backend related challenges. To manage platform infrastructure for scalability, high availability, and security. To ensure product scalability, high availability, and top-notch code … alerting to maintain high availability. To build, operate, and secure the APIs, backend, and even cloud infrastructure. To incorporate security best practices into the API design and implementation. To evaluate product code against specifications and gathering requirements. To address problems and document all reported issues and actions taken. ...

Senior Product Manager: Lead US Payments Expansion

Location
City of Edinburgh, Scotland, United Kingdom
product roadmap, translate customer needs into scalable payments propositions and collaborate with leadership to drive the strategy forward. You will work with engineering on API design, partner management and go-to-market teams to package and sell the proposition, while remaining hands-on and results-driven. #J ...

Hybrid Laravel Developer: Greenfield & Legacy Apps

Location
Birmingham, England, United Kingdom
applications, employing PHP, Laravel and Vue.js, with the opportunity to influence technical decisions and deliver impact. The role offers exposure to modern web technologies, API design, and cross-functional teamwork in a regulated environment, with emphasis on quality and professional #J-18808-Ljbffr ...

Enterprise AI Solutions Engineer - Hybrid

Location
Greater London, England, United Kingdom
Team to build reusable patterns and drive responsible AI adoption across multiple units. The roles require hands-on AI/ML/LLM development, API design, and a delivery-focused mindset in a large, regulated landscape. Hybrid work and a strong governance focus are offered. #J-18808-Ljbffr ...

Senior Mobile SDK Engineer — Stable APIs, Live Support

Location
Greater London, England, United Kingdom
product, so binary size, startup cost, thread safety, and backward compatibility are the job. You will own what you build end to end, from API design through release and live integration support. Based in-office (hybrid) in London or Ljubljana, Slovenia, you will work on Android (Kotlin ...

Senior Backend Engineer - Cross-Border Payments (C#/.NET)

Location
Easthampstead, England, United Kingdom
rebuilding the platform layer behind cross-border payments and seeks a mid-level back-end engineer to own problems end-to-end—from API design to production reliability and launch. You will work in a small team with direct access to product, compliance, and operations, building services that ...

Backend Engineer

Location
United Kingdom
Encryption, access control and auditability built in from day one. What you'll bring You've designed and run production backend systems Strong in API design, databases and cloud infrastructure You think about security, reliability and scale early Comfort with ownership in a small, fast team Nice ...

AWS Cloud Engineer

Hiring Organisation
Anson Mccade
Location
London, United Kingdom
Employment Type
Permanent, Part Time, Work From Home
Salary
£70,000
working with modern cloud technologies, and contributing throughout the full software delivery lifecycle. The successful candidate will work within an autonomous DevOps team, helping design, develop, deploy, and maintain cloud applications and services that support critical operational requirements. They'll have the opportunity to influence technical decisions, explore … . They'll be part of a collaborative engineering environment that encourages innovation, continuous improvement, and the adoption of modern DevOps practices. Key Responsibilities Design, develop, deploy, and maintain cloud-based applications and services using AWS. Build and manage cloud infrastructure using Infrastructure as Code (IaC) tools. Identify appropriate ...

AWS Cloud Engineer

Hiring Organisation
Anson Mccade
Location
Manchester, North West, United Kingdom
Employment Type
Permanent, Part Time, Work From Home
Salary
£70,000
working with modern cloud technologies, and contributing throughout the full software delivery lifecycle. The successful candidate will work within an autonomous DevOps team, helping design, develop, deploy, and maintain cloud applications and services that support critical operational requirements. They'll have the opportunity to influence technical decisions, explore … . They'll be part of a collaborative engineering environment that encourages innovation, continuous improvement, and the adoption of modern DevOps practices. Key Responsibilities Design, develop, deploy, and maintain cloud-based applications and services using AWS. Build and manage cloud infrastructure using Infrastructure as Code (IaC) tools. Identify appropriate ...

Senior Software Engineer

Hiring Organisation
Reed Technology
Location
Berkhamsted, Hertfordshire, United Kingdom
Employment Type
Permanent
Salary
£60000 - £80000/annum
resolve defects, ensuring the reliability and stability of the company's platforms aligning with the broader Technology Strategy. Day-to-day of the role: Design, build, test, and ship features across .NET/C# backend and Angular frontend applications. Write clean, well-tested, maintainable code and uphold those standards … administration tasks including deployments, patching, and environment configuration to reduce manual effort and risk. Contribute to architectural decisions, providing input on technology choices, system design, and platform adoption. Use Infrastructure as Code (IaC) to manage and provision Azure resources, ensuring environments are reproducible, auditable, and consistent. Build and maintain ...

Mac UI Frameworks Engineer,Cocoa

Location
Greater London, England, United Kingdom
Apple's platforms. You will be responsible for bringing your ideas to life through all stages of their development: from initial research, to API design and proposals, to testing and development in Swift, to documentation and offering guidance to adopters. You'll join us in energetic discussions … team's work is at a critical part of the macOS stack and we are core contributors to new operating system features, such as design refreshes, new hardware, intelligence integration, and many others - we build what users expect from all apps on the platform. You'll also have ...

Lead Solutions Engineer — Apps & Gaming (Advertising Tech)

Location
Greater London, England, United Kingdom
turn business needs into robust technical outcomes. The role requires a hands-on leader with a track record in software delivery, ML infrastructure, and API design, capable of guiding cross-functional groups and communicating complex concepts clearly across audiences. #J-18808-Ljbffr ...

Cuspai Mid-Level · On-site · London, UK 07 de nov. United Kingdom Scientific Software Engineer (Lab Integration) back-end next.js python fastapi +8

Location
Greater London, England, United Kingdom
material.What You Will DoHelp shape how we connect to partner labs around the world, accounting for different levels of automation and AI-readiness, then design, build and operate the services that send experiment requests from our AI agents and reliably bring results back.Build APIs and data models (e.g. FastAPI … throughput experimentation data pipelines.Strong software engineering background, with production experience building and operating backend services.Deep fluency in Python, including typed, well-tested code and API design.Experience designing distributed systems that integrate with external parties: APIs, message queues or event-driven architectures, and data contracts.Solid understanding of security practices ...

Frontend Lead

Location
England, United Kingdom
integrates seamlessly with our Backend-for-Frontend (BFF) layer, powered by Spring Boot microservices , and deployed on Google Cloud Platform (GCP) . Key Responsibilities: Design and build a high-performance frontend framework using React.js and Micro Frontend (MFE) architecture . Implement SSR/CSR hybrid strategies to optimize rendering … enhance frontend-backend interactions. Improve frontend performance using lazy loading, predictive prefetching, tree shaking, and edge caching. Collaborate with backend engineers to optimize API designs and system efficiency. Define best practices for state management using Redux and Redux-Saga/Thunk for handling complex application flows. Optimize frontend applications ...

Backend Engineer (Ruby), Plan: Spec-Driven Development

Location
United Kingdom
interfaces, and an artificial intelligence gateway.You'll join a small, distributed team working on one of GitLab's highest-visibility product bets, collaborating with design partners toward a public beta. In your first year, you'll lead major features from an unclear problem through release, help shape scope with … other engineers, and influence technical decisions across agent workflows and evaluation methods.What you’ll do- Lead backend features from early product discussions through technical design, implementation, rollout, and post-launch learning.- Build the flows, application programming interfaces, and data models behind agent-generated work items, implementation plans, durable specifications ...

Senior C++ Software Engineer – AI Developer Tools

Location
United Kingdom
NVIDIA’s AI-powered developer-tools ecosystem. Build reliable, performance-sensitive systems connecting native C++ tools with Genie’s retrieval and agentic capabilities. Design maintainable interfaces between C++ applications and AI services exposed through Python, MCP, REST APIs, and structured tool calling. Contribute to agentic workflows, retrieval systems, ingestion … experience. 5+ years of professional experience developing complex production software in modern C++. Strong knowledge of software architecture, concurrency, debugging, performance optimization, and maintainable API design. Experience owning complex systems from design through implementation, deployment, and ongoing operation. Practical experience with AI-powered applications, agentic workflows, developer tools ...

Senior Full Stack Engineer (UK)

Location
United Kingdom
first, builds with modern tooling, and brings strong React/TypeScript front-end instincts alongside solid back-end capability. What You’ll Own: Design and build full stack features end-to-end, from React/TypeScript front ends to APIs and back-end services. Lead with an AI-first … development workflow, tooling, and processes — with an eye for where AI can accelerate delivery and quality. Collaboration & Communication Work closely with Engineering, Product, and Design to deliver high-quality products across the full stack. Contribute to architectural decisions and help define standards for AI-assisted development across the team. ...

Lead Software Engineer - AWS - Lead AI/ML Platform Engineer

Location
Greater London, England, United Kingdom
value creativity, collaboration, and a commitment to excellence. As a Software Engineer in the Firmwide AI/ML Deployment Platform team, you will design and develop cloud-native solutions that support model deployment across the organization. You will work closely with data scientists and engineers to deliver features that … seamless integration of control plane and client accounts Develop and implement APIs for platform functionalities such as automated retraining, scheduling, endpoint deployments, and autoscaling Design robust features to support a growing internal customer base, including multi-region and disaster recovery capabilities Architect and implement model monitoring solutions, with emphasis ...

Member of Technical Staff - Applications

Location
Greater London, England, United Kingdom
usable interfaces. Feed delivery learnings back into platform patterns and defaults so the next system ships faster. What You\'ll Work With Full-Stack & API Development: React, TypeScript, REST, gRPC, FastAPI, Go services, API design. Auth & Governance: OIDC authentication, RBAC, audit logging. Workflows & Integrations: Event-driven systems, workflow … About You Strong full-stack engineering background with experience shipping production-grade applications end-to-end. Comfortable owning the full delivery surface — UI through API through auth — without needing to hand off between layers. Experience integrating with external systems or customer environments and making those integrations reliable and maintainable. ...

Security Engineer - Hybrid London: App & Cloud Security

Location
Greater London, England, United Kingdom
core to our product and to client trust. As our Security Engineer, you will make our platform, cloud estate and internal systems secure by design, working hand in hand with our engineering team. Reporting to the Head of Engineering, this is a permanent, hands-on role where you will … SaaS estate. Own email security and authentication. Own endpoint security across our Windows and Mac fleet, including EDR policy tuning and validation testing. Design and maintain federated authentication with clear rollout guides and rollback procedures. Security monitoring and detection Build, extend and maintain security monitoring across our technical estate ...

Senior Laravel Developer

Location
Greater London, England, United Kingdom
pick up themselves. Work alongside our London team, with direct access to the people building and supporting Jodie. What you'll own Design and ship Laravel services, APIs and background jobs with clear contracts and useful observability. Make webhook processing resilient to retries, duplicate events and partial failures. Improve … ship. What you'll bring Substantial experience shipping and maintaining production Laravel and PHP applications. A strong grasp of relational databases, queues, caching and API design. Practical experience with automated tests, secure authentication and safe deployments. Examples of investigating a production problem and improving the system afterwards. Useful ...