Backend Developer in United Kingdom

🚀 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 At WRITER, our enterprise customers are building mission-critical AI applications that transform how their businesses operate. As a senior support engineer, your top priority is helping our developer personas and technical users succeed with our platform. You'll act as a leading voice for our enterprise support function, handling intricate customer issues directly while working in a complex and ambiguous environment to drive impactful value across our customers' businesses. You'll collaborate closely with Customer Success, Education, Product, Engineering, and Sales to create great experiences and help customers get the most out of the platform. By leveraging an automation-first mindset, you'll scale our support operations and use our own AI tools to solve problems faster and more efficiently. This role is available for hybrid work in our New York City and London hubs. and you will report directly to the manager of support engineering. 🦸🏻‍♀️ What you'll do Own

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

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

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 Palantir Foundry is an end-to-end platform for data-driven decision-making. We're transforming the way organisations securely integrate their data, so they can then build reliable, critical applications atop that unified foundation. Our customers use Foundry to perform rich analyses that drive core operations within their organisations. They can also build sophisticated, full-fledged programs, such as common operating pictures, alert-triaging inboxes, and resource allocation planning tools driven by rich-ML models. As a Full Stack Engineer focused on application development in Foundry, you will be responsible for crafting the tools used by thousands of users to build the sophisticated applications that power their businesses. You will be architecting and developing interfaces, state management and access patterns to support data-intensive workflows that are both powerful and approachable. You may spend one day interviewing users to better understand their needs and identifying product gaps to improve. The next day, you might find yourself considering that customer context along with signal gathered from other customers in different industries, brainstorming approaches to handling intricate UX needs with your teammates. You’ll regularly be faced with sophisticated technical problems, requiring you to scope out the solution design and finding an incremental path to shipping the new features. As part of this, you will own APIs and schemas that power your frontend code, or work with other backend engineers in developing them together. We're hiring engineers who are passionate about solving real-world problems and empowering both customer app builders and

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 Software Engineers at Palantir build software at scale to transform how organizations 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. Our Product Development organization is made up of small teams of Software Engineers. Each team focuses on a specific aspect of a product. Our infrastructure teams are responsible for the lowest layers of our software stack, often focused on database technologies, distributed systems, large scale data systems, security, and application infrastructure. As a Software Engineer on infrastructure working on our Foundry platform, you'll contribute high-quality code to underpin Palantir Foundry and Gotham with performant, secure, and scalable building blocks, enabling products deployed to the most important institutions in the public and private sector. You'll build the foundational capabilities that power our products used by research scientists, aerospace engineers, intelligence analysts, and economic forecasters, in countries around the world. We’re hiring engineers who are passionate about solving real-world problems and empowerin

Synthesia is the world’s leading AI video platform for business, used by over 90% of the Fortune 100. Founded in 2017, the company is headquartered in London, with offices and teams across Europe and the US. As AI continues to shape the way we live and work, Synthesia develops products to enhance visual communication and enterprise skill development, helping people work better and stay at the center of successful organizations. Following our recent Series E funding round, where we raised $200 million, our valuation stands at $4 billion. Our total funding exceeds $530 million from premier investors including Accel, NVentures (Nvidia's VC arm), Kleiner Perkins, GV, and Evantic Capital, alongside the founders and operators of Stripe, Datadog, Miro, and Webflow. About the role You will focus on friction points around primarily backend issues for all teams in Engineering (90 Engineers). How should we do inter-service testing? Some teams are using monorepo, others aren’t. How can we bring overall stability up? Generally steering BE in the right direction. In the near future, standardising things across all of Engineering and bringing R&D teams (another 40 Engineers and Researchers) closer. You will have ownership of projects that span quarters, requiring you to have the ability to break a problem down into small steps that can be delivered and validated iteratively. You will evaluate your own work, leveraging our data pipeline and frameworks that we have established to understand the impact your features have on our commercial objectives and pivoting where necessary. You will consider the long-term direction of Engineering, making sure that we are developing the engineering capabilities that will allow us to stay ahead of the challenges we are likely to encounter in 12-18 months' time. You will work end-to-end, from our client application written in React to our monolithic backend written in Python, and lead projects that span across multiple teams. What we're looking

Synthesia is the world’s leading AI video platform for business, used by over 90% of the Fortune 100. Founded in 2017, the company is headquartered in London, with offices and teams across Europe and the US. As AI continues to shape the way we live and work, Synthesia develops products to enhance visual communication and enterprise skill development, helping people work better and stay at the center of successful organizations. Following our recent Series E funding round, where we raised $200 million, our valuation stands at $4 billion. Our total funding exceeds $530 million from premier investors including Accel, NVentures (Nvidia's VC arm), Kleiner Perkins, GV, and Evantic Capital, alongside the founders and operators of Stripe, Datadog, Miro, and Webflow. We’re looking for a Principal Engineer to join the ML Platform team at Synthesia. Our team builds and operates the systems that allow researchers and product teams to train, serve, and deploy generative models reliably and efficiently . This includes research infrastructure, production serving systems, internal tooling, and the platform interfaces that connect them. A growing part of our mission is making these systems more automation-friendly and agent-oriented , so that workflows can increasingly be operated through reliable tooling rather than manual effort. We’re looking for a strong generalist with a systems mindset: someone who is comfortable working across infrastructure, backend systems, and tooling, and who has seen ML systems in practice. this is not a pure ML Engineer role. We’re especially interested in people who think deeply about reliability, scalability, performance, and resource efficiency in complex production environments. This is a hands-on IC role with significant ownership. You’ll help shape how our ML platform evolves as we scale the number of models, workloads, tools and teams relying on it. What you’ll do Design and improve the platform systems that support model training, evaluation, an

Synthesia is the world’s leading AI video platform for business, used by over 90% of the Fortune 100. Founded in 2017, the company is headquartered in London, with offices and teams across Europe and the US. As AI continues to shape the way we live and work, Synthesia develops products to enhance visual communication and enterprise skill development, helping people work better and stay at the center of successful organizations. Following our recent Series E funding round, where we raised $200 million, our valuation stands at $4 billion. Our total funding exceeds $530 million from premier investors including Accel, NVentures (Nvidia's VC arm), Kleiner Perkins, GV, and Evantic Capital, alongside the founders and operators of Stripe, Datadog, Miro, and Webflow. We’re looking for an Engineer to join the ML Platform team at Synthesia. Our team builds and operates the systems that allow researchers and product teams to train, serve, and deploy generative models reliably and efficiently . This includes research infrastructure, production serving systems, internal tooling, and the platform interfaces that connect them. A growing part of our mission is making these systems more automation-friendly and agent-oriented , so that workflows can increasingly be operated through reliable tooling rather than manual effort. We’re looking for a strong generalist with a systems mindset: someone who is comfortable working across infrastructure, backend systems, and tooling, and who has seen ML systems in practice. this is not a pure ML Engineer role. We’re especially interested in people who think deeply about reliability, scalability, performance, and resource efficiency in complex production environments. This is a hands-on IC role with significant ownership. You’ll help shape how our ML platform evolves as we scale the number of models, workloads, tools and teams relying on it. What you’ll do Design and improve the platform systems that support model training, evaluation, and product

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

At Speechmatics, we’re expanding our user platform offering. We're looking for a Senior Front-End Software Engineer with a strong product mindset to help drive that growth. This is an opportunity to own end-to-end feature development at a leading-edge AI company, from shaping the user experience through to shipping and iterating based on real user feedback and analytics data. What you'll do Own product features from ideation through to delivery, contributing to UX thinking, frontend execution, and post-launch iteration Build polished, accessible user interfaces using React, JavaScript, HTML, and CSS Make UX and UI decisions independently, collaborating closely with designers and PMs rather than waiting on detailed handoffs Design and run A/B tests to validate product decisions and surface insights that improve the user experience Use analytics tooling such as Mixpanel to understand how people interact with the product and feed that learning back into what gets built Partner with backend engineers, product managers, and designers to ship features that genuinely move the needle for users and the business Write and maintain robust UI tests, taking ownership of quality in production and at scale Run user interviews and meet customers to understand how people use the product and what drives adoption What you'll need Proficiency in React, JavaScript, HTML, and CSS with a track record of shipping production-quality frontend code A product-minded engineering approach Comfort owning UX and UI decisions independently Hands-on experience with iterative development practices, including A/B testing and feature experimentation Familiarity with user analytics tools such as Mixpanel or a comparable platform Experience with UI testing frameworks and a solid grounding in frontend engineering best practices Confidence collaborating cross-functionally with designers, PMs, and backend engineers A track record of using user feedback and data to improve features Nice to have Experience us

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

🚀 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

We're looking for an ML Data & Platform Engineer to own the infrastructure that powers our speech AI models: the pipelines that source and prepare training data, and the platform that trains, evaluates, and serves them in production. Speech AI has a data problem most ML teams don't, and you'll be at the centre of solving it, working as part of our ML team to remove friction across the entire lifecycle and get better models into production faster. This is a broad, cross-functional role suited to someone who enjoys working across the full stack: data infrastructure, distributed systems, and production ML, and who takes ownership of problems end to end rather than waiting to be told what to fix. What you'll do Designing, building, and maintaining scalable data pipelines for ingesting, transforming, validating, and storing large datasets used to train our models Developing and maintaining web scraping and data acquisition solutions to keep training datasets fresh, high-quality, and available at scale Building and operating the infrastructure that lets the ML team deploy and evaluate new models quickly, and that serves models efficiently and reliably in production Optimising infrastructure for both iteration speed and production reliability, including GPU utilisation, job scheduling, and training efficiency Implementing observability (monitoring, logging, alerting) across data pipelines and ML systems to catch issues early and keep things running smoothly Troubleshooting complex issues across distributed systems, spanning data infrastructure, training, and inference Continuously improving our data and MLOps practices, and helping shape the roadmap for how our platform evolves as we scale What you'll need Strong proficiency in Python and SQL, with a solid backend or data engineering foundation Hands-on experience with containerisation and orchestration (Docker, Kubernetes), and working with a major cloud provider Experience building data pipelines and ETL/ELT processe

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're seeking an exceptional Android engineer to join a small, high-impact team dedicated to creating the world's most valuable AI application, judged by the impact it delivers to users. You'll shape cutting-edge mobile experiences, blending technical mastery with a keen product sense to deliver brilliance that resonates with users. You will work on the most critical product or technical challenge at any given time. BASIC QUALIFICATIONS: Proficient in Kotlin, Jetpack Compose and reactive programming. Has a strong product sense and high craft bar. Builds intuitive and delightful user experiences. Experienced in architecting modern large production apps while embodying technical excellence. Strong sense of ownership and agency. Able to put on multiple hats and take responsibility for large areas. Able to optimize for performance, stability and reliability. PREFERRED SKILLS AND EXPERIENCE: A proven track record of shipping standout apps or features that demonstrate both technical excellence and exceptional product intuition. Deep expertise in the Android ecosystem and related development tools (Android Studio, Gradle, etc.). Rust for working with our backend components. COMPENSATION AND BENEFITS: £107,000 - £262,0