Backend Engineer Api in United Kingdom

SpaceXAI’s mission is to create AI systems that can accurately understand the universe and aid humanity in its pursuit of knowledge. Our team is small, highly motivated, and focused on engineering excellence. This organization is for individuals who appreciate challenging themselves and thrive on curiosity. We operate with a flat organizational structure. All employees are expected to be hands-on and to contribute directly to the company’s mission. Leadership is given to those who show initiative and consistently deliver excellence. Work ethic and strong prioritization skills are important. All employees are expected to have strong communication skills. They should be able to concisely and accurately share knowledge with their teammates. ABOUT THE ROLE: As an ideal candidate you have a good understanding of how highly scalable and reliable production infrastructure is built. Most of our backend infrastructure is written in Rust. So familiarity with a compiled language such as C++, Rust, or Go is highly beneficial. RESPONSIBILITIES: Build the SpaceXAI API that serves our models to developers worldwide Own the end-to-end system responsible for high-throughput inference, handling billions of tokens per minute with low latency and high availability, including model serving infrastructure, request routing, SDK development, rate limiting, observability, and efficient scaling BASIC QUALIFICATIONS: Expert knowledge of either Rust or C++ Experience in designing, implementing, and maintaining reliable and horizontally scalable distributed systems Knowledge of service observability and reliability best practices Experience in operating commonly used databases such as PostgreSQL, Clickhouse, and MongoDB PREFERRED SKILLS AND EXPERIENCE: Experience with LLM inference engines and serving frameworks (e.g., SGLang, TensorRT, vLLM) Experience designing or building with agent SDKs and agent orchestration frameworks Experience with Docker, Kubernetes, and containerized applicatio

Who we are About Stripe Stripe is a financial infrastructure platform for businesses. Millions of companies - from the world’s largest enterprises to the most ambitious startups - use Stripe to accept payments, grow their revenue, and accelerate new business opportunities. Our mission is to increase the GDP of the internet, and we have a staggering amount of work ahead. That means you have an unprecedented opportunity to put the global economy within everyone's reach while doing the most important work of your career. About the Organization Money as a Service (MaaS) oversees a diverse portfolio of Stripe's core platforms and services. Our Stripe Treasury suite helps users manage and move their funds with ease, providing the robust financial infrastructure and tools they need to power their businesses on a global scale. Team Matching: exact team matching for one of the subteams within this org will begin during final stages. Please note we may also consider you for different orgs based on your experience, location, etc. More information on our team matching process can be found here . What you’ll do We’re looking for Backend Engineers who want to make an impact on managing money at a global scale with a passion for building ergonomic APIs. You’ll play a key role in extending our foundational Money Management APIs and services powering our Treasury products globally. Our team collaborates with many cross-functional teams – from Infrastructure to Product Manager – at Stripe to deliver innovative solutions that address evolving user needs. Responsibilities Scope, design, build, and maintain APIs, services, and large-scale systems that reliably and efficiently handle billions of money movement requests Debug and solve critical production issues across services and multiple levels of the stack Mentor engineers to help them grow Collaborate with stakeholders across the company to build new features at large-scale, while improving internal engineering standards,

GitLab is the intelligent orchestration platform for DevSecOps. GitLab enables organizations to increase developer productivity, improve operational efficiency, reduce security and compliance risk, and accelerate digital transformation. More than 50 million registered users and more than 50% of the Fortune 100* trust GitLab to ship better, more secure software faster. The same principles built into our products are reflected in how our team works: we embrace AI as a core productivity multiplier, with all team members expected to incorporate AI into their daily workflows to drive efficiency, innovation, and impact. GitLab is where careers accelerate, innovation flourishes, and every voice is valued. Our high-performance culture is driven by our values and continuous knowledge exchange, enabling our team members to reach their full potential while collaborating with industry leaders to solve complex problems. Co-create the future with us as we build technology that transforms how the world develops software. * Fortune 500® is a registered trademark of Fortune Media IP Limited, used under license. Claim based on GitLab data. Fortune 100 refers to the top 20% ranked companies in the 2025 Fortune 500 list, published in June 2025. Fortune and Fortune Media IP Limited are not affiliated with, and do not endorse products or services of GitLab. An overview of this role As a Backend Engineer on the Gitaly team, you’ll help build GitLab’s Git data storage tier, a standalone product that provides reliable, secure, and fast access to Git repositories through application programming interfaces (APIs) and storage operations. You’ll work at the boundary between GitLab and Git to make repository access performant and dependable for GitLab.com , self-managed customers, and GitLab Dedicated. Our work spans distributed storage, repository management, high availability, performance, observability, and operational excellence. We’re currently building the next generation of source co

A World-Changing Company Palantir builds the world’s leading software for data-driven decisions and operations. By bringing the right data to the people who need it, our platforms empower our partners to develop lifesaving drugs, forecast supply chain disruptions, locate missing children, and more. The Role Backend Software Engineers at Palantir build software at scale to transform how organisations use data. Our Software Engineers are involved throughout the product lifecycle, from idea generation, design, prototyping, and production delivery. You will collaborate closely with technical and non-technical teammates to understand our customers' problems and build products that solve them. We encourage movement across teams to share context, skills, and experience, so you'll learn about many different technologies and aspects of each product. Engineers work autonomously and make decisions independently, within a community that will support and challenge you as you grow and develop, becoming a strong technical contributor and engineering leader. Your day-to-day workflow will vary, adapting to the requirements of our users and the technical challenges that arise. One day, you may find yourself collaborating with other engineers to architect a new system that enables a novel workflow, the next you could be fine-tuning performance to enable low-latency operational outcomes. Our Product Development organisation is made up of small teams of Software Engineers. Each team focuses on a specific aspect of a product and work collaboratively to build cross functional capabilities, streamline user workflows and continuously improve our software's efficiency and reliability. We’re hiring engineers who are passionate about solving real-world problems and empowering both developers and end-users to work optimally. If you’re motivated to develop reliable, performant, and scalable systems, and to design robust APIs and primitives, this role offers the opportunity to make a

A World-Changing Company Palantir builds the world’s leading software for data-driven decisions and operations. By bringing the right data to the people who need it, our platforms empower our partners to develop lifesaving drugs, forecast supply chain disruptions, locate missing children, and more. The Role Backend Software Engineers at Palantir build software at scale to transform how organisations use data. Our Software Engineers are involved throughout the product lifecycle, from idea generation, design, prototyping, and production delivery. You will collaborate closely with technical and non-technical teammates to understand our customers' problems and build products that solve them. We encourage movement across teams to share context, skills, and experience, so you'll learn about many different technologies and aspects of each product. Engineers work autonomously and make decisions independently, within a community that will support and challenge you as you grow and develop, becoming a strong technical contributor and engineering leader. Your day-to-day workflow will vary, adapting to the requirements of our users and the technical challenges that arise. One day, you may find yourself collaborating with other engineers to architect a new system that enables a novel workflow, the next you could be fine-tuning performance to enable low-latency operational outcomes. Our Product Development organisation is made up of small teams of Software Engineers. Each team focuses on a specific aspect of a product and work collaboratively to build cross functional capabilities, streamline user workflows and continuously improve our software's efficiency and reliability. We’re hiring engineers who are passionate about solving real-world problems and empowering both developers and end-users to work optimally. If you’re motivated to develop reliable, performant, and scalable systems, and to design robust APIs and primitives, this role offers the opportunity to make a sig

About the Team Our London-based team builds the backend systems that help ChatGPT scale reliably. We work on infrastructure close to the product, partnering with engineering teams to improve the performance, resilience, and operability of critical user-facing systems. Our work combines backend software engineering with distributed systems and production reliability. We build shared capabilities, improve high-traffic workflows, and make it easier to introduce new product functionality without compromising performance or availability. About the Role This role is for software engineers who want to build and evolve backend systems operating at significant scale. You’ll write production code, design shared infrastructure, and solve technical challenges involving performance, distributed systems, and system reliability. You’ll also own how those systems behave in production: how changes are rolled out, how issues are detected and diagnosed, and how recurring operational problems can be addressed through better software and system design. This is a strong fit for backend engineers who enjoy complex systems problems and want a direct connection between the infrastructure they build and the experience of ChatGPT users. In this role, you will: Design, build, and maintain backend systems supporting high-traffic ChatGPT experiences. Develop shared services, APIs, and infrastructure that help product teams build and launch new capabilities safely. Improve the performance, scalability, and efficiency of production systems as usage and product complexity grow. Build and improve systems for asynchronous processing and other large-scale backend workloads. Lead architectural improvements and infrastructure migrations while maintaining correctness, compatibility, and safe rollout and rollback. Strengthen monitoring, alerting, and diagnostics to detect problems early and reduce customer impact. Participate in on-call, incident response, and root-cause analysis, and turn operational lea

Here’s a summary of the role: Build cloud software that matters, grow your technical depth, and use modern AI tooling to do your best work. This is a hands-on engineering role for someone who enjoys solving product problems, writing clean code, and helping services run reliably at scale. You’ll work on secure, scalable microservices and APIs using TypeScript, AWS , and modern engineering practices. You’ll be part of a collaborative product engineering team where you can own features, contribute to design discussions, support production systems, and keep growing across backend, cloud, and AI-assisted development workflows. Here’s a breakdown of what you’ll do, not all of it, just the important stuff: Design, build, test, and improve backend services and APIs using Node.js, TypeScript, and AWS . Take ownership of well-defined features from planning through release, including code quality, deployment, and production support . Work closely with product managers, designers, and other engineers to turn requirements into practical, reliable solutions. Contribute to technical design conversations, code reviews, and engineering standards that keep the team moving well. Use AI tools to speed up research, coding, debugging, testing, and documentation, while checking outputs carefully and applying sound judgment. Help keep systems secure, observable, and maintainable by improving monitoring, reliability, and day-to-day development practices. These are the essentials you’ll need to get an interview: 3 to 5 years of professional software engineering experience building production applications in an agile environment. Strong backend development skills with Node.js and TypeScript, including experience building APIs or microservices. Experience with React or Angular in a product engineering environment. Hands-on experience with

Here’s a summary of the role: Build software that matters, take real technical ownership, and use modern AI tooling to do your best work. This is a hands-on senior engineering role for someone who enjoys solving complex product problems, shaping robust solutions, and helping teams deliver reliable services at scale. You’ll work on secure, scalable microservices and APIs using TypeScript, AWS, and modern engineering practices. You’ll play a leading role within a collaborative product engineering team, owning complex features end to end, contributing to design and architectural decisions, supporting production systems, and helping raise the bar across backend, cloud, and AI-assisted development workflows. Here’s a breakdown of what you’ll do, not all of it, just the important stuff: Own and deliver complex backend services and APIs using Node.js, TypeScript, and AWS , from technical design through release and production support. Contribute to design and architecture discussions, making pragmatic decisions that balance delivery speed, maintainability, scalability, and security. Mentor and support less experienced engineers through code reviews, pairing, technical guidance, and day-to-day collaboration. Work closely with product managers, designers, and engineers across the team to turn requirements into practical, reliable solutions. Use AI tools to accelerate coding, debugging, testing, research, and documentation, while validating outputs carefully and applying sound judgment. Strengthen service reliability, observability, and engineering quality by improving monitoring, incident response, testing, and development practices. These are the essentials you’ll need to get an interview: 5 to 8 years of professional software engineering experience delivering production systems in an agile environment. Strong backend development s

We’re looking for a Software Engineer to help shape AI governance for developer tooling at Coder. This role sits on our AI Governance team, which builds and maintains two enterprise-grade components of Coder's AI governance stack. AI Gateway is a centralized LLM gateway that sits between coding agents and providers such as OpenAI or Anthropic, providing organizations with audit trails, token tracking, cost control, and centralized authentication. Agent Firewall wraps those agents with default-deny network policies, controlling which domains and methods they can reach inside workspaces. This team works across the full stack - from Go backend and React frontend, to integrating with LLM provider APIs. Day to day, you'll be shipping features, hardening security boundaries, collaborating with enterprise customers on real-world policy needs, and contributing to Coder's open-source ecosystem. What you'll do here Design and build product features that push the standard for remote development in self-hosted environments Create and improve upon popular open source projects that integrate with VS Code, JetBrains, and other developer tools Champion best practices to both internal team members and external contributors Collaborate with Product and Design teams at Coder, as well as with partners like JetBrains, to execute key product integrations Document the design, implementation, and operations of systems for knowledge sharing within the team Work alongside Customer Success teams to support Coder’s enterprise user base Work with cutting-edge AI technologies to create seamless, painless developer experiences Rapidly iterate from prototype to implementation in a highly adaptive, reactive team environment What we're looking for 3+ years of full-stack experience writing code in a professional setting, with 1+ year(s) writing Go (ideally in current or most recent position) Proficiency in building distributed systems in Go Excellent verbal and written communication skills Exceptiona

🚀 About WRITER WRITER is where the world's leading enterprises orchestrate AI-powered work. Our vision is to expand human capacity through superintelligence. And we're proving it's possible – through powerful, trustworthy AI that unites IT and business teams together to unlock enterprise-wide transformation. With WRITER's end-to-end platform, hundreds of companies like Mars, Marriott, Uber, and Vanguard are building and deploying AI agents that are grounded in their company's data and fueled by WRITER's enterprise-grade LLMs. Valued at $1.9B and backed by industry-leading investors including Premji Invest, Radical Ventures, and ICONIQ Growth, WRITER is rapidly cementing its position as the leader in enterprise generative AI. Founded in 2020 with office hubs in San Francisco, New York City, Seattle, Austin, Chicago, and London, our team thinks big and moves fast, and we're looking for smart, hardworking builders and scalers to join us on our journey to create a better future of work with AI. 📐 About the role We’re seeking a highly skilled fullstack software engineer to join our engineering team building advanced AI-driven agent systems that execute autonomous workflows, orchestrate multi-step tasks, and extend human capacity across enterprise applications. In this role, you’ll play a key part in designing, building, and scaling next-generation AI agents that integrate with enterprise data and services to solve real-world problems. You will collaborate with cross-functional teams to turn complex agent concepts into production-ready systems. 🦸🏻‍♀️ What you'll do Design, implement, and maintain scalable, secure agent-driven services and systems that autonomously accomplish tasks using modern AI frameworks. Develop and enhance robust infrastructure and high-throughput APIs, focusing on core agent capabilities such as memory, communication channels, skills, intelligent decision logic, security and workflow management. Integrate agent capabilities with backend services

SpaceXAI’s mission is to create AI systems that can accurately understand the universe and aid humanity in its pursuit of knowledge. Our team is small, highly motivated, and focused on engineering excellence. This organization is for individuals who appreciate challenging themselves and thrive on curiosity. We operate with a flat organizational structure. All employees are expected to be hands-on and to contribute directly to the company’s mission. Leadership is given to those who show initiative and consistently deliver excellence. Work ethic and strong prioritization skills are important. All employees are expected to have strong communication skills. They should be able to concisely and accurately share knowledge with their teammates. ABOUT THE ROLE: We are seeking a talented Software Engineer to join our X Money team, focused on building a revolutionary global payment network that will serve over 600 million users and rival the world’s largest financial institutions. In this role, you will specialize in backend development, designing and optimizing robust microservices to ensure scalability, security, and reliability. You will support full-stack efforts, collaborate with cross-functional teams on payments, fraud detection, and compliance initiatives, and contribute to the creation of a high-scale financial products platform. This is an opportunity to work on greenfield projects in a fast-paced, startup-like environment, driving innovation at the intersection of AI and finance. RESPONSIBILITIES: Develop backend services, APIs, and data models to support high-volume, multi-user environments. Work with iOS, Android & Web client engineers to ship products. Design robust infrastructure and microservices for payments, transactions, growth, monetization, and engagement across platforms. Build and maintain fullstack features, including user dashboards, personalized experiences, content delivery, interactive tools, assessments, and real-time analytics. Le

🚀 About WRITER WRITER is where the world's leading enterprises orchestrate AI-powered work. Our vision is to expand human capacity through superintelligence. And we're proving it's possible – through powerful, trustworthy AI that unites IT and business teams together to unlock enterprise-wide transformation. With WRITER's end-to-end platform, hundreds of companies like Mars, Marriott, Uber, and Vanguard are building and deploying AI agents that are grounded in their company's data and fueled by WRITER's enterprise-grade LLMs. Valued at $1.9B and backed by industry-leading investors including Premji Invest, Radical Ventures, and ICONIQ Growth, WRITER is rapidly cementing its position as the leader in enterprise generative AI. Founded in 2020 with office hubs in San Francisco, New York City, Seattle, Austin, Chicago, and London, our team thinks big and moves fast, and we're looking for smart, hardworking builders and scalers to join us on our journey to create a better future of work with AI. 📐 About the role We’re seeking a highly skilled fullstack software engineer to join our engineering team building advanced AI-driven agent systems that execute autonomous workflows, orchestrate multi-step tasks, and extend human capacity across enterprise applications. In this role, you’ll play a key part in designing, building, and scaling next-generation AI agents that integrate with enterprise data and services to solve real-world problems. You will collaborate with cross-functional teams to turn complex agent concepts into production-ready systems. 🦸🏻‍♀️ What you'll do Design, implement, and maintain scalable, secure agent-driven services and systems that autonomously accomplish tasks using modern AI frameworks. Develop and enhance robust infrastructure and high-throughput APIs, focusing on core agent capabilities such as memory, communication channels, skills, intelligent decision logic, security and workflow management. Integrate agent capabilities with backend services

Sr. Software Engineer The Team + The Role Pendo's engineering teams build the product experiences that help customers understand, improve, and act on product usage data. This team is focused on AI-powered features that turn raw usage signals into automatic, actionable suggestions, reducing the manual work customers need to do before they can get value from Pendo. As a Senior Software Engineer, you will help shape and ship intelligent product experiences from discovery through delivery. You will work full-stack with a lean toward frontend, using TypeScript, Vue.js, backend services, and AI coding tools to build high-quality features on a small, fast-moving team. This role also owns product judgment: validating problems with customers, sizing opportunities, defining success metrics, and making pragmatic tradeoffs in ambiguous spaces. This role is based in our Sheffield office. What this looks like day-to-day AI-powered feature delivery: Build and ship features that use AI to turn product usage data into actionable suggestions for customers. You will work end to end across the experience, with attention to quality, usability, and the unique failure modes of AI-backed products. Full-stack engineering: Own delivery across the frontend and backend, with a strong lean toward TypeScript, Vue.js, DOM-level work, component architecture, and in-browser data capture. You will reason about backend services and APIs while building polished, reliable customer-facing experiences. Product discovery: Help validate problems, shape scope, and test direction before and while building. You will join customer calls, test prototypes, and use real feedback to make sure the team is solving meaningful problems. Success metrics and iteration: Define what success looks like for the features you build and use product usage data to guide iteration. You will not just close tickets; you will measure whether the work is creating the intended customer impact. AI-enabled development: Use AI coding too

As a Staff Software Engineer on Coder’s Agentic Engineering team, you’ll shape the systems behind our agentic development experience. You’ll work across the agent harness, integrations, and workflows that connect agents with real development environments. You’ll stay hands-on while setting the team's technical direction. You’ll lead complex work, make sound architectural decisions, and help other engineers do their best work. What you’ll do here Set technical direction across Coder’s agent harness, integrations, and workflows. Design and build production systems in Go, with work across React and TypeScript where needed. Evolve agent execution, tool use, context management, streaming, and long-running workflows. Extend our provider-agnostic architecture as models and capabilities change. Lead complex projects from early ambiguity through production. Raise the engineering bar through design reviews, code reviews, and technical mentorship. Partner with Product and Design on clear, useful agent experiences. Improve the reliability, performance, and operability of agentic systems. What we’re looking for Deep experience building and operating production software systems. Strong hands-on experience with Go. Experience with React and TypeScript. Hands-on experience building systems around LLMs and agentic workflows. Experience with model APIs, tool calling, context management, or agent loops. Strong distributed systems knowledge. Working knowledge of AWS. A track record of setting technical direction without formal authority. Strong architectural judgment and comfort working through ambiguity. Someone who makes the engineers around them better. Our tech stack Backend: Go, Postgres Frontend: TypeScript, React Infrastructure: AWS, Kubernetes Observability: Prometheus, Grafana CI/CD: GitHub Actions Bonus tacos if you have (Tacos? If you need an ice-breaker, ask how we say thanks by giving tacos!) Experience building coding agents, developer tools, or cloud development environm

GitLab is the intelligent orchestration platform for DevSecOps. GitLab enables organizations to increase developer productivity, improve operational efficiency, reduce security and compliance risk, and accelerate digital transformation. More than 50 million registered users and more than 50% of the Fortune 100* trust GitLab to ship better, more secure software faster. The same principles built into our products are reflected in how our team works: we embrace AI as a core productivity multiplier, with all team members expected to incorporate AI into their daily workflows to drive efficiency, innovation, and impact. GitLab is where careers accelerate, innovation flourishes, and every voice is valued. Our high-performance culture is driven by our values and continuous knowledge exchange, enabling our team members to reach their full potential while collaborating with industry leaders to solve complex problems. Co-create the future with us as we build technology that transforms how the world develops software. * Fortune 500® is a registered trademark of Fortune Media IP Limited, used under license. Claim based on GitLab data. Fortune 100 refers to the top 20% ranked companies in the 2025 Fortune 500 list, published in June 2025. Fortune and Fortune Media IP Limited are not affiliated with, and do not endorse products or services of GitLab. An overview of this role As a Senior Fullstack Engineer on GTM Engineering, you will design and build the backend systems and services that power our go-to-market and growth platforms, while also contributing across the stack where needed. This is a strong fit if you want to work in a 0 to 1 space where you can shape what gets built, guide architectural choices, and guide work from specification through production health. What you'll do Design, build, and maintain backend services and APIs that support GTM and growth platforms Contribute across the stack, including frontend work, when a feature or project calls for it Contribute