Jobs in United Kingdom

Application Developer in United Kingdom

73 active opportunities · Updated October 2026

Explore current application developer jobs across United Kingdom. Filter by work mode, employment type, experience, department, date posted and distance.

S
📍 London, England, United Kingdom· Full-time
✓ High-confidence listing

£107K – £262K/yr

Quick readStrong listing-quality and freshness signals

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

SQLPostgreSQLMongoDBDocker
W
📍 United Kingdom· Full-time
✓ Quality checkedCompany trend +37.5%

🚀 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

PythonAWSGCPRest
W
📍 London, England, United Kingdom· Full-time
✓ High-confidence listing
Quick readStrong listing-quality and freshness signals

WPP is the trusted growth partner for the world’s leading brands. We unite cutting-edge media intelligence and data solutions, world-class creativity, next-generation production, transformative enterprise solutions and expert strategic counsel in a single company – powered by exceptional talent and our agentic marketing platform, WPP Open, to help our clients navigate change, capture opportunity and deliver transformational growth. We work with the world's most valuable brands and have global reach across 100+ markets, with deep local expertise. Our people are the key to our success. We're committed to fostering a culture of creativity, belonging and continuous learning, attracting and developing the brightest talent, and providing exciting career opportunities that help our people grow. For more information, visit WPP.com. Why we're hiring: We're looking for an Application & Development Security Lead to help shape and strengthen secure software development governance across one of the world's largest technology and creative ecosystems. Working within WPP's Digital Security & Risk Management team, you'll partner with engineering, product and platform teams to govern secure-by-design ways of working, improve software security governance, and provide oversight across modern development environments. This role isn't about writing code day-to-day. Instead, you'll influence governance of how secure software is built, deployed and maintained across cloud-native platforms, APIs, AI-enabled applications and global engineering teams. This is an opportunity to influence software security governance at global scale, helping shape how security supports innovation across one of the world's largest and most diverse technology environments. You'll work alongside talented security and engineering professionals while helping build secure, resilient products and platforms for the future. What you'll be doing: Define an

AWSAzureCI/CDGit
PE
📍 United Kingdom· Full-time· Hybrid
✓ Quality checked

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

PE
📍 United Kingdom· Full-time
✓ Quality checked

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 Forward Deployed Software Engineers (FDSEs) understand our customers’ greatest pain points and design end-to-end solutions to address them. FDSEs solicit constant feedback on their work from both customers and colleagues, improving our products over time with rapid iteration cycles. FDSEs deploy ground breaking technical solutions to solve our customers’ hardest problems. Projects often start with a nebulous question like “Why are we losing customers?” or “How can we more effectively identify instances of money laundering?” FDSEs lead the way in developing a solution, from high-level system design and prototyping to application development and data integration. As an FDSE, you leverage everything around you: Palantir products, open source technologies, and anything you and your team can build to drive real impact. You work with customers around the globe, where you gain rare insight into the world’s most important industries and institutions. We help our customers detect insider trading, improve disaster relief, fight healthcare fraud, and more. Each mission presents different challenges, from the regulatory environment to the nature of the data to the user population. You will work to accommodate all aspects of an environment to drive real technical outcomes for our customers. Core Responsibilities FDSEs responsibilities look similar to those of a startup CTO: you’ll work in small teams and own end-to-end execution of high stakes projects. A day might span discussing architecture with fellow engineers, wrangling massive-scale data, coding a custom web app, speaking with customer executives, or establishing strategy for your team. Do you aspire to

O
📍 United Kingdom· Full-time
✓ High-confidence listingCompany trend -100%

From £184K/yr

Quick readStrong listing-quality and freshness signals

Secure Every Identity, from AI to Human Identity is the key to unlocking the potential of AI. Okta secures AI by building the trusted, neutral infrastructure that enables organizations to safely embrace this new era. This work requires a relentless drive to solve complex challenges with real-world stakes. We are looking for builders and owners who operate with speed and urgency and execute with excellence. This is an opportunity to do career-defining work. We're all in on this mission. If you are too, let's talk. The Auth0 Sales Team Auth0 supports Okta’s vision of freeing anyone to safely use any technology by providing a secure, highly available, enterprise-grade platform that secures billions of log-ins every year for Consumers and SaaS applications. This team in the UKI is growing exponentially with net new growth headcount being released to support the demand in the market. The Auth0 Enterprise Account Executive Opportunity As an Auth0 Enterprise Account Executive , you'll play a pivotal role in expanding our footprint and driving significant revenue growth in the Public Sector . You'll be instrumental in demonstrating the profound value of our platform to Application Development teams , including Engineering, Product, Security, and Architecture leaders . This isn't just about closing deals; it's about building lasting partnerships, identifying new opportunities, and nurturing existing customer relationships to ensure their continued success and expansion with Auth0. What You'll Do: Drive New Business Growth: Proactively generate and nurture top-of-funnel activity to create a robust pipeline of new customer opportunities. Master the Sales Cycle: Execute every sales engagement with precision, leveraging a methodical and controlled sales approach to navigate complex deals. Strategic Territory Management: Develop and execute comprehensive territory plans, demonstrating strong operational excellence and delivering accurate forecasts. Engage Technical Audience

AWSRestMachine LearningAI
O
📍 United Kingdom· Full-time
✓ High-confidence listingCompany trend -100%

From £164K/yr

Quick readStrong listing-quality and freshness signals

Secure Every Identity, from AI to Human Identity is the key to unlocking the potential of AI. Okta secures AI by building the trusted, neutral infrastructure that enables organizations to safely embrace this new era. This work requires a relentless drive to solve complex challenges with real-world stakes. We are looking for builders and owners who operate with speed and urgency and execute with excellence. This is an opportunity to do career-defining work. We're all in on this mission. If you are too, let's talk. The Auth0 Sales Team Auth0 supports Okta’s vision of freeing anyone to safely use any technology by providing a secure, highly available, enterprise-grade platform that secures billions of log-ins every year for Consumers and SaaS applications. This team in the UKI is growing exponentially with net new growth headcount being released to support the demand in the market. The Auth0 Enterprise Account Executive Opportunity As an Auth0 Enterprise Account Executive , you'll play a pivotal role in expanding our footprint and driving significant revenue growth. You'll be instrumental in demonstrating the profound value of our platform to Application Development teams , including Engineering, Product, Security, and Architecture leaders . This isn't just about closing deals; it's about building lasting partnerships, identifying new opportunities, and nurturing existing customer relationships to ensure their continued success and expansion with Auth0. What You'll Do: Drive New Business Growth: Proactively generate and nurture top-of-funnel activity to create a robust pipeline of new customer opportunities. Master the Sales Cycle: Execute every sales engagement with precision, leveraging a methodical and controlled sales approach to navigate complex deals. Strategic Territory Management: Develop and execute comprehensive territory plans, demonstrating strong operational excellence and delivering accurate forecasts. Engage Technical Audiences: Employ a sophistica

AWSRestMachine LearningAI
S
📍 United Kingdom· Full-time
✓ Quality checkedCompany trend -100%

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. Location: Europe remote or London hybrid About the role: As our engineering and research organisation grows, so does the complexity of securing it. Our Application Security team is at the forefront of that challenge — building AI-native security tooling, embedding security into the development lifecycle at scale, and finding ways to make a small, highly capable team punch well above its weight. We're looking for an Engineering Manager to lead and grow the AppSec team. This is not a coordination role. You'll be leading a team of exceptionally senior and staff-level engineers who are deeply self-directed and technically excellent. To earn their trust and enable their best work, you'll need to be genuinely close to the craft — able to engage at depth on threat modelling, agentic security tooling, SDLC design, and application risk. You'll also own AppSec strategy and be accountable for how the function scales alongside a product organisation that is growing fast and leaning heavily into AI-assisted development. Important note: Anyone working as a manager within the Infosec team will need to follow the Infosec Team Management Tenets . Key Responsibilities: Lead, support, enable and grow the AppSec team — owning hirin

JavaScriptPythonJavaAWS
PE
📍 United Kingdom· Full-time
✓ Quality checked

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 organisations around the world use data. As a Software Engineer Intern, you’ll have an opportunity to grow more quickly than you ever envisioned, as you contribute high-quality code directly to Palantir Gotham, Palantir Foundry, or Palantir Apollo: products that are deployed at some of the most important institutions across the public and private sectors. You'll create features used by research scientists, aerospace engineers, intelligence analysts, and economic forecasters, in countries around the world. Palantir's Product Development organisation is made up of small teams of Software Engineers, each focusing on a specific aspect of a product. For example, you might join a team that builds a Foundry front-end application, or a component of the Gotham release infrastructure. We encourage communication and collaboration among teams to share context, skills, and experience, so you'll learn about many different aspects of each product. Core Responsibilities As a Software Engineer, you are involved throughout the product lifecycle - from idea generation, design, and prototyping to execution and shipping while also being paired with a mentor dedicated to your growth and success. You'll collaborate closely with technical and non-technical counterparts to understand our customers' problems and build products that tackle them. One of the most effective ways to understand what our users need is to meet them. You may receive an opportunity to tour the assembly line at an auto-manufacturer or join a counter-terror analyst at their desk to really understand their mission and difficulties. SWE

TypeScriptJavaReactGit
PE
📍 United Kingdom· Full-time· Hybrid
✓ Quality checked

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 organisations around the world use data. In this role, you’ll have an opportunity to grow more quickly than you ever envisioned as you contribute high-quality code directly to Palantir Gotham, Palantir Apollo, or Palantir Foundry: products that are deployed at some of the most important institutions across the public and private sectors. You'll create features used by research scientists, aerospace engineers, intelligence analysts, and economic forecasters in countries around the world. Palantir's Product Development organisation is made up of small teams of Software Engineers, each focusing on a specific aspect of a product. For example, you might join a team that builds a Foundry front-end application, or a component of the Gotham release infrastructure. We encourage communication and collaboration among teams to share context, skills, and experience, so you'll also have the opportunity to learn about other business areas. Core Responsibilities As a Software Engineer, you are involved throughout the product lifecycle - from idea generation, design, and prototyping, to execution and shipping, all while also being paired with a mentor dedicated to your growth and success. You'll collaborate closely with technical and non-technical counterparts to understand our customers' problems and build products that tackle them. One of the most effective ways to understand what our users need is to meet them. You may receive an opportunity to tour the assembly line at an auto-manufacturer or join a counter-terror analyst at their desk to really understand their mission and difficulties. SWE p

TypeScriptJavaReactGit
PE
📍 United Kingdom· Full-time· Hybrid
✓ Quality checked

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

S
📍 London, England, United Kingdom· Full-time
✓ High-confidence listing

£107K – £262K/yr

Quick readStrong listing-quality and freshness signals

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

ReactAIKotlinRust
PG
📍 Bristol, United Kingdom· Full-time
✓ High-confidence listing
Quick readStrong listing-quality and freshness signals

Why Sony Interactive Entertainment? Sony Interactive Entertainment isn’t just the Best Place to Play — it’s also the Best Place to Work. Sony Interactive Entertainment (SIE) is the company behind the PlayStation brand. As a subsidiary of Sony Group Corporation, we’re part of a proud legacy of innovation and excellence. SIE is a dynamic technology company, delivering cutting-edge hardware and network services to more than 100 million people and an entertainment leader, home to some of the most beloved and recognizable intellectual properties (IP) in the world. Our role at SIE is to create and nurture the experiences under the PlayStation brand, a name synonymous with entertainment excellence and creativity. Join us and be a member of the team that tests the development tools used to create every PlayStation® game. This is a great opportunity to continue a career in Software Testing, working on industry leading development tools and being mentored by experts in their field. What you’ll be doing Developing tests for new applications, new features and regressions. Developing test strategies with application teams. Automating tests as part of our continuous integration systems. Investigating issues and creating reproducible test cases. Conducting manual, exploratory testing. Reporting test results clearly (including performance and coverage). Developing tooling to help reduce test time and ease test execution. Make suggestions and recommendations for improvements to help shape the finished product. Collaborate with global, cross-functional teams in a multicultural environment to develop organisation-wide test strategies and infrastructure. Mentoring peers, sharing best practices, and influencing quality engineering approaches. What we are looking for 5+ years experience in developing tests for software applications. Experience of automating tests. A good understanding of software testing techniques. Good C# programming skills. Understanding of C++. Experience in triaging

PythonLinuxRestAI
FB
📍 London, England, United Kingdom· Full-time
✓ High-confidence listing
Quick readStrong listing-quality and freshness signals

Location : Come and join us in London! Freenow by Lyft empowers smarter mobility decisions helping people to move freely and cities to thrive. One of our core goals for 2026 is the complete digitalization of the European taxi market. We work with taxi companies to provide them with our advanced dispatch and fleet management software completely free of charge. This enables them to significantly reduce operating costs, successfully differentiate themselves from major ride-hailing providers, and manage a profitable, sustainable business. To support this, we are looking for a Sales Manager who will become the face of this initiative. We look forward to your application and can't wait to have you on board for this journey! YOUR DAILY ADVENTURES WILL INCLUDE: Prospect, engage, travel and pitch our Dispatch tool to SME taxi companies in the UK. You are the driving force behind converting traditional vehicle fleets into modern, connected Freenow by Lyft partners. Guide entrepreneurs, fleet owners, and senior dispatchers through the fear of operational change. Act as the voice of our partners. You will gather on-the-ground feedback about our software and collaborate directly with our Product and Strategy teams to help "co-build" the ultimate solution. TO BE SUCCESSFUL IN THIS ROLE: 3-5 years of professional experience in areas such as B2B business development, sales, or account management. Experience in mobility, logistics, or selling SaaS solutions to SMEs is especially valued. Proven track record of managing a B2B pipeline and handling objections. You understand that even when a product is free, you still have to expertly "sell" the time, effort, and operational shift required to adopt it. Strong communication skills with the ability to build trust and long-term relationships. The ability to deeply understand a partner's business operations at a process level. You are skilled at guiding new partners step by step through the change process and ensuring they smoothly a

GitAIGoRust
FB
📍 London, England, United Kingdom· Full-time
✓ High-confidence listing
Quick readStrong listing-quality and freshness signals

Location : Come and join us in London! Freenow by Lyft empowers smarter mobility decisions helping people to move freely and cities to thrive. One of our core goals for 2026 is the complete digitalization of the European taxi market. We work with taxi companies to provide them with our advanced dispatch and fleet management software completely free of charge. This enables them to significantly reduce operating costs, successfully differentiate themselves from major ride-hailing providers, and manage a profitable, sustainable business. To support this, we are looking for a Sales Manager who will become the face of this initiative. We look forward to your application and can't wait to have you on board for this journey! YOUR DAILY ADVENTURES WILL INCLUDE: Prospect, engage, travel and pitch our Dispatch tool to SME taxi companies in the UK. You are the driving force behind converting traditional vehicle fleets into modern, connected Freenow by Lyft partners. Guide entrepreneurs, fleet owners, and senior dispatchers through the fear of operational change. Act as the voice of our partners. You will gather on-the-ground feedback about our software and collaborate directly with our Product and Strategy teams to help "co-build" the ultimate solution. TO BE SUCCESSFUL IN THIS ROLE: 3-5 years of professional experience in areas such as B2B business development, sales, or account management. Experience in mobility, logistics, or selling SaaS solutions to SMEs is especially valued. Proven track record of managing a B2B pipeline and handling objections. You understand that even when a product is free, you still have to expertly "sell" the time, effort, and operational shift required to adopt it. Strong communication skills with the ability to build trust and long-term relationships. The ability to deeply understand a partner's business operations at a process level. You are skilled at guiding new partners step by step through the change process and ensuring they smoothly a

GitAIGoRust
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