Senior Fullstack Software Engineer

Join Our Engineering TeamAt CoreWeave, we are revolutionizing the AI landscape. Our Monolith AI Engineering Team is dedicated to constructing and enhancing the foundational platform that drives the most sophisticated engineering simulations and AI workflows. Our mission is to transform into the super-intelligent AI test lab for the engineering sector, empowering our clients to "ship science, faster." We focus on advancing distributed architecture and facilitating the next wave of agentic interfaces and physical AI, providing the reliable and scalable infrastructure that the world’s leading engineering firms depend on.Your RoleWe are seeking a talented Fullstack Engineer with a Frontend Focus. You will take charge of the Monolith platform’s product surface, which offers a data-rich, workflow-centric web interface where engineers can design experiments, compare outcomes, interact with agents, and convert intricate physical test data into actionable insights. Your collaboration with Design, Product, and Backend Engineering teams will be crucial in delivering a UI and UX that is fast, intuitive, and dependable for non-ML expert engineers. Additionally, you will contribute to our Python backend services as needed.Position OverviewThis is an IC5 Fullstack Staff Engineer role with a significant emphasis on frontend development (approximately 80–90%). We are also open to exceptional candidates for the Senior Fullstack Engineer II (IC4) level who can perform at a staff-like capacity. You will be responsible for the Monolith web application, focusing on component architecture, design system evolution, performance, and user experience for complex, data-rich workflows. You will also engage with our Python services (FastAPI/Flask) to shape and integrate APIs and implement new platform capabilities, enhancing user experiences.

Join our dynamic team as a Senior Frontend Engineer at AECOM, where you will be at the forefront of developing innovative web applications and user interfaces. We are looking for an enthusiastic engineer with a passion for crafting seamless and engaging digital experiences. You will collaborate with cross-functional teams to design and implement robust solutions that enhance user interaction and satisfaction.

Join us at elasticstage as a Senior Frontend Engineer and play a crucial role in revolutionizing the music industry. Our innovative technology enables the production of on-demand vinyl records, providing a platform for music creators to effortlessly create and sell their music worldwide at no cost. We collaborate with top record labels, streaming services, digital providers, distributors, and renowned global artists to deliver a comprehensive solution for physical media. Our mission is to empower small and emerging artists, offering them seamless access to market their vinyl and CDs to fans through our state-of-the-art production and fulfillment centers across Europe, the USA, and Asia.The vinyl market has experienced consistent growth of over 20% annually for the past 16 years, and CDs are witnessing a resurgence for the first time in two decades. By 2030, we anticipate nearly 200 million music creators globally, with AI further accelerating this growth. Many artists aspire to have their music available on vinyl or CD for their friends, family, and fans, and our scalable on-demand technology makes this accessible without the burden of high costs or minimum orders. At elasticstage, we provide easy and affordable access to this burgeoning market.As a Senior Frontend Engineer, you will take ownership of our front-end platform, engaging in hands-on development while providing technical leadership and direction. You will collaborate closely with product, design, and backend engineering teams to deliver exceptional user experiences across our e-commerce platform, creator tools, and operational systems.Join us and contribute to scaling a dynamic, high-profile disruptor in the music industry!

lovable is looking for a Fullstack Enterprise Engineer in London. This position centers on building and delivering software solutions that meet enterprise standards. Collaboration with teams across disciplines is a key part of the work. Role overview This role involves developing software from both the front-end and back-end, ensuring each component integrates smoothly. The focus is on producing reliable, maintainable code that supports business needs. What you will do Develop and implement software solutions for enterprise use Work with cross-functional teams to deliver projects Apply experience in both front-end and back-end technologies Requirements Experience with front-end and back-end development Ability to collaborate effectively with colleagues from different specialties Commitment to producing high-quality, impactful results

TransPerfect is seeking a Senior Frontend Engineer to join its London-based team. This position plays a key role in developing and maintaining software products that support global operations. The focus is on delivering high-quality, reliable solutions that drive the company’s technology forward. Role overview The Senior Frontend Engineer will work on the design, development, and execution of software products. This includes taking responsibility for the quality of the user interface and ensuring that products meet both technical and user needs. The role involves collaborating with other teams to deliver solutions that support TransPerfect’s worldwide business. About the TechOps team TechOps has supported TransPerfect’s growth for more than ten years. The team builds and maintains technology that streamlines processes for both clients and internal teams. Projects range from workflow improvements to developing scalable interfaces for the GlobalLink platform, all aimed at making complex systems easier to use. What you will do Lead frontend development for software products used across global operations Ensure the quality and reliability of user interfaces Work closely with cross-functional teams to deliver scalable solutions

Location: London Start date: Immediate The Role: We are seeking exceptionally skilled and motivated software engineers who take pride in their craft to enhance our Engineering team based in London. As a successful candidate, you will collaborate within a cross-functional team that includes product managers and designers, working closely with the wider business to deliver effective code that addresses real-world challenges for both internal and external clients. You will take charge of the services overseen by your team, ensuring their development aligns with the overarching AlphaSights Engineering strategy, while also mentoring junior engineers. If you are passionate about problem-solving through coding and aspire to work alongside outstanding colleagues in a high-achievement environment, this position is ideal for you. What You’ll Do: Design Solutions: Define optimal technical solutions to business problems, contributing to a scalable architectural vision that aims to become the world's leading research platform. Ship Working Code: Our primary tech stack consists of React for the frontend and Kotlin microservices with Postgres for the backend, alongside some legacy services built in Ruby on Rails. We continually assess new technologies that could enhance our stack. Deploy and Iterate: We release updates frequently to our customers, utilizing CircleCI and Spinnaker for CI/CD, gathering feedback promptly to inform subsequent iterations. Build Your Competency: You will rapidly advance your skills by developing market-leading technology alongside experienced colleagues in a high-performance environment. Engineers can also utilize our L&D budget to accelerate their development of specific technical competencies. Maintenance and Troubleshooting: Diligently monitor our services to catch errors proactively, diagnose root causes, and deploy fixes before users are affected. Who You Are: You likely hold a degree in a STEM subject, but we are also open to candidates who have honed their skills through alternative pathways. Experience: Proven experience at a similar level within a mature Engineering team, with aspirations to elevate your career. We seek individuals with outstanding potential. Technical Expertise: Extensive knowledge in frontend engineering, including designing, building, and maintaining robust web applications.

Join Our Team at CapiCapi is revolutionizing the way businesses in emerging markets manage their international supplier payments—making it simple, swift, and equitable.With over $18M in support from leading investors including Creandum, Y Combinator, General Catalyst, and influential figures from Revolut, Checkout, Stripe, and Remitly, we are dedicated to establishing the robust financial infrastructure that emerging markets truly deserve.Our commitment to facilitating global trade empowers local enterprises to accelerate growth, create job opportunities, and enhance prosperity in their communities.Our mission is to uplift GDP in emerging markets by fostering a more equitable and accessible global financial system. We aim to streamline the payment processes for importers, enabling businesses to expand swiftly and act as catalysts for national prosperity.Our dynamic team of approximately 80 individuals, spread across 10 countries, embodies ambition and a results-driven mindset, striving to make a meaningful impact in the world. We are eager to welcome new talent to our team!Explore Capi's mission & values.Role OverviewAs a Senior Fullstack Engineer, you will be part of a compact, high-performing team of engineers and product leaders responsible for scaling our platform and amplifying our impact.From day one, you will collaborate closely with our founding team based in London and Paris, influencing the product vision and shaping the technical architecture of our solutions. This role is pivotal in developing technology that addresses customer challenges as we grow our offerings and enhance our footprint in emerging markets.Empathy and curiosity are essential to uncovering the root causes of problems, along with the creativity to devise solutions that harmonize impact, effort, and user satisfaction.Key ResponsibilitiesEngage in the product lifecycle from conception through to UI design, backend logic, deployment, feedback gathering, and performance measurement.Communicate effectively both internally and externally regarding new features, gathering feedback prior to implementation and articulating them upon launch.Determine and oversee delivery milestones, ensuring alignment between engineering and product priorities.

Join our dynamic team at minderacraft as a Staff Full-Stack Engineer. In this pivotal role, you will take charge of both backend and frontend development, crafting high-quality, scalable solutions while establishing engineering standards for the team. This position offers a unique blend of hands-on development and technical leadership, where you will mentor fellow engineers and collaborate closely with our product and platform teams.Your expertise will be crucial as you work with cutting-edge backend services developed in Kotlin, alongside rich frontend applications built with React and Next.js, utilizing TypeScript. Additionally, you will engage with cloud-native infrastructure on either Azure or AWS.This position is offered as an initial 6-month contract (outside IR35) with a requirement to be onsite in London Paddington three days a week.

Join our passionate team at Ledger, where we are dedicated to redefining the landscape of digital ownership. Our mission is to empower users, creators, and enterprises to take control of their value with unparalleled freedom through technology that is accessible to everyone. We thrive on innovation, fostering a culture of curiosity and problem-solving that encourages every team member to challenge norms and develop groundbreaking solutions. At Ledger, we are committed to making self-custody accessible, giving individuals the keys to their financial futures. If you’re eager to make a significant impact, we invite you to become part of our journey.As the leading global platform for digital assets and Web3, Ledger secures over 20% of the world’s crypto assets through our advanced hardware wallets, with more than 7.5 million units sold across 200 countries. With headquarters in Paris and offices in various locations including London, we employ around 600 skilled professionals dedicated to developing secure products and services that allow individuals and businesses to manage their crypto assets with confidence.The TeamYou will be an integral part of the E-commerce Engineering team, which is responsible for the entire customer experience on ledger.com. This team oversees the customer journey from discovery to checkout, utilizing a modern technology stack (Next.js, Shopify, Contentful, Vercel) to deliver high-performance, conversion-optimized experiences.In our dynamic, product-focused environment, we prioritize frequent deliveries and continuous optimization in performance, SEO, and conversion rates.What You’ll Be DoingAs a Senior Frontend Engineer, you will play a pivotal role in shaping the web experiences that millions of customers rely on. This hands-on position involves significant ownership, where you will lead complex projects from conception through to production, influence technical direction, and uplift team standards through mentorship.Your responsibilities will include:End-to-End Project OwnershipLead the development of impactful features from inception to deployment.

blp-digital is looking for a Senior Frontend Engineer to work onsite in London. This role centers on building modern web applications, working closely with both designers and backend developers to deliver user experiences that are intuitive and reliable. Key responsibilities Lead the frontend development of both new and existing web applications Collaborate with designers to turn concepts into polished, effective interfaces Work with backend engineers to ensure seamless integration between frontend and backend systems Work location This position requires working onsite at the London office.

Wise is seeking a Fullstack Engineer to focus on account setup features. This role centers on building and improving the systems that help customers create and manage their accounts smoothly. Role overview The Fullstack Engineer will work on both front-end and back-end components that support the account setup journey. Expect to collaborate closely with team members to identify pain points and deliver solutions that make onboarding easier for users. What you will do Develop and refine account setup processes to improve customer experience Work with engineers and other stakeholders to solve technical challenges Contribute to a collaborative team environment Requirements Experience working as a fullstack engineer Comfortable collaborating with others to solve problems Interest in building seamless, user-friendly account setup flows

Senior Frontend Engineer - Elevate User Experiences Are you a seasoned Frontend Engineer looking to make a significant impact? Join our dynamic and agile delivery team at ClearScore, where we are dedicated to crafting innovative experiences for our users through the latest technologies. If you thrive in a high-performance, entrepreneurial environment that celebrates the art of developing cutting-edge products and tackling complex challenges, we want to hear from you! As a valued member of our established cross-functional squad, you will focus on advancing our design system, enhancing our logged-out website, and exploring other groundbreaking technologies. We foster a culture of continuous improvement and creativity, inviting new team members to share their ideas and methodologies. Bring your expertise, and we'll share our knowledge in a collaborative and enjoyable atmosphere. At ClearScore, our world-class engineers are pivotal in fulfilling our mission to enrich the financial lives of millions. To learn more about our technology stack, visit our 2026 Tech Radar. Discover our work culture through our Behavioural Principles and Engineering Principles. Explore additional insights on our Tech Blogs on Medium. Your Responsibilities: Design, develop, and maintain full-stack solutions using Node.js and TypeScript, delivering data-driven user interfaces and backend services. Create intuitive client UX utilizing design systems and server-driven UI frameworks. Optimize and scale databases for large-scale applications, employing SQL, PostgreSQL, and indexing strategies to ensure performance and maintainability. Collaborate closely with skilled colleagues to implement, monitor, and optimize real-time data pipelines with Kafka, ensuring robust message handling and distributed system performance to enhance your features. Take ownership of end-to-end performance optimization, both client-side and server-side. Lead the deployment and maintenance of production-grade code and databases across multiple global markets. Monitor post-release performance, utilizing tools for reliability and system health. Engage in an Agile environment, mentoring team members across various specializations and fostering a culture of learning and continuous improvement.

About Kernel Kernel builds AI-powered data solutions for RevOps teams working with CRM systems. The company is supported by $14M in Series A funding from investors linked to Plaid, OpenAI, and Slack. Kernel aims to provide an AI-first alternative to established data providers like Dun & Bradstreet. Teams at organizations such as Navan, Gong, Mistral, and AlphaSense use Kernel's products to streamline and improve their operations. The engineering team manages around 30 billion tokens daily and runs more than 1.8 million agents, all on a streamlined architecture with a single database and queue. For scale, Kernel's queue processes about 365 million transactions each day, comparable to Visa's daily volume. All of this is achieved by a small, focused team. Role Overview Kernel is looking for a Frontend Product Engineer in London. This is a T-shaped role with a strong emphasis on frontend work. The position involves working closely with both product and engineering to design and ship user-focused features, maintain infrastructure, and support Kernel's growth. While deep design skills are not required, a solid grasp of UI/UX principles and a sharp eye for detail matter. The team values proactive, adaptable engineers who communicate clearly. With a lean structure, engineers are trusted to make decisions and ship code independently. This role offers the chance to help drive Kernel's growth from $3M to $30M ARR, taking ownership of projects from start to finish and shaping product and infrastructure decisions. What You'll Do Design and build product features that improve user workflows Work with design, product, and engineering to deliver strong user experiences Write and maintain clean, scalable code across the stack Support the performance and reliability of large-scale data operations Automate workflows to boost developer efficiency and reduce manual steps Integrate with CRMs and external APIs Join roadmap discussions and contribute technical insights What You'll Bring At least 6 years of experience in software or product engineering Strong skills with frontend technologies and frameworks

LocationLondon, UK - Hybrid – 3 days in office - Office location: Central London (Victoria area)About the RoleJoin our dynamic team as a Mobile/Frontend Engineer where you will leverage your expertise in React Native and TypeScript to enhance and develop a tablet-based Point of Sale (POS) application.This position is perfectly suited for individuals with a strong mobile development background grounded in frontend technologies. Most of our codebase is built using React Native, along with a bit of Next.js for our web interfaces.You will focus on elevating UI quality, optimizing performance, and crafting new features in a fast-paced startup setting where AI technology is an integral part of our development process.Key ResponsibilitiesDevelop and maintain features for our tablet-based POS applicationUtilize React Native and TypeScript extensivelyEnhance UI/UX quality and streamline the existing codebaseRefactor and optimize frontend code for improved performance and reliabilityCollaborate with product engineers and backend developersRapidly deliver new features while ensuring high standards of code qualityEffectively utilize AI-assisted development toolsRequired Experience & SkillsProven experience with React Native and TypeScriptBackground in frontend engineering (JavaScript, React ecosystem)Experience in developing mobile or tablet applications (excluding native Swift/Kotlin)Ability to enhance and maintain existing codebasesExperience in startup or fast-paced settingsAdept at rapidly iterating on product featuresPreferred QualificationsFamiliarity with Next.jsExperience in POS, payment systems, or fintech productsUnderstanding of AI-driven development workflowsExperience collaborating with product or design teamsWhat We ValueWe seek front-end engineers who are passionate about their craft and committed to delivering exceptional user experiences.

Join our dynamic team at Ratio Recruitment Ltd as a Frontend Web Developer specializing in React. We are seeking a talented individual who is passionate about creating innovative web applications and enhancing user experiences. You will be responsible for developing responsive web interfaces, collaborating with designers and backend developers, and ensuring high-quality code through best practices.

Join our dynamic team at Another Company as a Fullstack Engineer, where your skills will be pivotal in building innovative solutions. You will collaborate with cross-functional teams to design, develop, and maintain web applications.This role offers an exciting opportunity to work with cutting-edge technologies and contribute to impactful projects.

About the RoleWe are excited to announce an opening for a Senior Frontend Engineer who will take charge of the user interface layer of ThreatAware's dynamic platform. Your main responsibilities will include developing the dashboard, enhancing data visualization, and crafting interfaces for our innovative AI-powered features. You will be working with TypeScript using Angular and React, reporting directly to the Head of Engineering, and collaborating closely with our R&D teams to seamlessly integrate AI functionalities into our platform. If you have a passion for creating stunning interfaces, an eye for detail, and a desire to tackle complex UI challenges with significant real-world implications, this position is perfect for you.Why Join ThreatAware?At ThreatAware, we provide security teams with a comprehensive source of truth for every device and tool within their organization. With over 150 integrations, rapid deployment in under 30 minutes, and real-time visibility across entire IT infrastructures, we have earned the trust of sectors such as finance, legal, energy, and healthcare. We're on a mission to build something even more impactful. After six years of curating accurate cyber asset data, we are now integrating AI to offer new methods for security teams to analyze their data, automate workflows, and proactively manage risks before they escalate. In this role, you will design intuitive interfaces that enhance user experience.Your ResponsibilitiesTake ownership of the frontend that transforms intricate security data into clear insights.Design and develop the platform dashboard and AI workspace UI using TypeScript (Angular and React) — ensuring a data-rich, real-time experience used daily by enterprise security teams.Tackle challenging visualization problems: managing thousands of security events, device interconnections, and AI-driven insights without overwhelming users.Establish a robust component architecture, design systems, and frontend standards that evolve as the team and product expand.Collaborate closely with R&D to translate AI capabilities into user-friendly, polished interfaces.Partner with product and design teams to define and enhance the user experience, rather than just executing it.Mentor junior frontend engineers and elevate the quality of frontend development within the team.Qualifications We SeekExtensive experience with TypeScript, Angular, and React, with a deep understanding of component architecture, state management, and performance optimization.A strong aesthetic sensibility, with a commitment to creating beautiful interfaces and a keen awareness of modern design trends, paying close attention to the details that contribute to a polished product.Proven track record in building data-intensive, high-performance web applications, ideally those that involve real-time data or complex visualizations.Ability to work in a collaborative environment and effectively communicate ideas and solutions.Prior experience in mentoring and guiding junior team members is a plus.

TransPerfect is searching for a Senior Frontend Engineer to join its London team. This role centers on building and refining software products that support both internal operations and client-facing solutions. The Senior Frontend Engineer will help guide development, quality, and delivery across a range of projects. The work involves collaborating with a global team to improve user experiences and streamline complex workflows. TransPerfect’s TechOps group has supported the company’s growth for over ten years, focusing on technology and services that make processes simpler for users and clients alike. Role overview Lead and contribute to the development of frontend features for software products Oversee quality and execution throughout the product lifecycle Work closely with international colleagues to deliver scalable solutions What we look for Experience in frontend engineering at a senior level Ability to collaborate within a global, cross-functional team Interest in improving both internal and client-facing systems This position is based in London and offers the chance to contribute to a company that values innovation and practical problem-solving.

About NevisNevis is revolutionizing the financial sector with the launch of the world's pioneering AI wealth management platform. In just nine months, we have successfully amassed over $50 billion in assets under management and we project to surpass $100 billion by year-end.Supported by leading investors, we have raised a total of $40 million from prominent firms including Sequoia Capital, ICONIQ, and Ribbit. This positions Nevis as one of the most highly funded and rapidly growing Series A startups in Europe.The RoleWe are seeking a passionate Frontend Software Engineer who appreciates the artistry of interfaces and sees code as a craft. In this pivotal role, you will design and develop Nevis’ core product, an innovative AI-native wealth management platform, and bring intelligent workflows to life for financial advisors around the world.You will collaborate closely with designers and backend engineers to swiftly transform ideas into reality. If you are enthusiastic about modern web technologies, value design excellence, and are eager to deliver impactful products, you will excel in our dynamic environment.What You’ll DoWork together with designers to create visually stunning and intuitive features.Translate intricate AI and financial data into user-friendly interfaces.Write clean, well-tested, and reusable code while mentoring others in best practices.Contribute to the evolution of our design system and enhance frontend craftsmanship.Rapidly prototype, solicit feedback, and iterate on solutions.Partner with backend engineers to seamlessly integrate APIs and visualize data.Pay meticulous attention to performance, accessibility, and the finer details that users appreciate.Who You AreYou possess extensive experience with TypeScript and a deep understanding of JavaScript.You are well-versed in React and eager to leverage the latest features.You have a thoughtful approach to component design, focusing on composable APIs and clear abstractions.You have an understanding of modern web dynamics including browser performance and the elements that contribute to a responsive interface.You are adept with contemporary tooling such as Vite, SCSS, and component libraries.You are proficient in delivering features from inception to production.