Founding Senior Backend Engineer at Tracer | London

Join Our TeamAt Tracer, we are pioneering the development of autonomous AI agents designed to enhance production data pipelines. As a venture-backed startup, we are supported by a network of seasoned investors and industry leaders who share our vision of transforming AI into a critical component of enterprise software in the coming decade. Our compact team i…

Join Tracer as a Junior Engineer and kickstart your career in engineering. This exciting role offers the opportunity to work on innovative projects while collaborating with a talented team in a dynamic environment. You will contribute to the development of cutting-edge solutions, gaining hands-on experience and advancing your skills in the engineering field.

About TracerTracer is an innovative early-stage startup that specializes in developing autonomous AI agents for production data pipelines. Backed by seasoned investors and industry leaders, we believe that AI will revolutionize production systems, becoming a key player in enterprise software over the next decade. Our team is composed of highly skilled professionals focused on delivering impactful results. Role OverviewWe are seeking a Founding AI Engineer (Staff) to join our London team. In this pivotal role, you will be responsible for designing the core architecture and launching an AI agent that generates reliable root cause analyses (RCAs) and actionable suggestions for significant alerts. While human oversight remains essential for production decisions, you will empower the agent to handle the intricacies of data management. Our Technology StackPython with LangGraph for multi-agent alert investigationsRust for high-performance systemsClickHouse for scalable event and investigation historyAWS and Terraform for self-managing infrastructureNext.js and TypeScript for an engaging front-end experience Your ResponsibilitiesAs the core architect, you will transform alerts into comprehensive investigations and RCAs. Your key tasks will include:Designing and building the primary alert investigation and RCA pipeline using PythonCreating essential systems such as alert ingestion, context enrichment, hypothesis orchestration, and reportingMaking critical architectural decisions to ensure reliability and observability from the outsetCollaborating with founders to refine and expand high-value alert typesDeveloping customer-ready integrations across the pipeline

About UsAt Tracer, we are pioneering the development of autonomous AI agents designed specifically for production data pipelines. As an early-stage, venture-backed startup, we are supported by seasoned professionals and investors who foresee AI's transformative impact on enterprise software over the coming decade. Our tight-knit team is comprised of senior experts who are keenly focused on execution and innovation. About the RoleWe are seeking a Lead AI Software Engineer to join our London team, responsible for creating and managing the core systems that convert production alerts into actionable root cause analyses (RCAs) and corrective suggestions. While the agent handles the heavy lifting, you will ensure that human oversight remains integral to production decisions.In this role, you will serve as the primary technical authority for our systems, collaborating closely with the founders and engaging in hands-on development. You’ll Love Our Tech StackPython + LangGraph (for multi-agentic alert investigation)Rust (to ensure speed and correctness)ClickHouse (to manage high-volume events and investigation histories)AWS + Terraform (for self-building infrastructure)Next.js + TypeScript (for dynamic front-end experiences) What You’ll DoIn this pivotal role, you will oversee the systems that transform alerts into thorough investigations and RCAs. Your responsibilities will include:Designing and building the core alert, investigation, and RCA pipeline using PythonCrafting and implementing essential systems, such as:Alert ingestion and normalizationContext enrichment and correlationProblem framing outputsHypothesis orchestration engineInvestigation execution runtimeInvestigation artifacts and reportingLeading crucial architectural decisions to ensure the system is observable, auditable, and reliable from day oneCollaborating with founders to effectively deploy a select few high-value alert types before gradually expanding our capabilitiesDeveloping customer-ready integrations throughout the pipeline

Join Tracer as a Founder's Associate Intern, where you will have the unique opportunity to work directly with our founding team. This internship is designed for highly motivated individuals eager to gain hands-on experience in a dynamic startup environment. You will assist in various projects, gaining insights into strategic decision-making and operational processes.

Join Aircall, a revolutionary unicorn in the AI-powered customer communications sphere, trusted by over 22,000 companies globally to enhance revenue, expedite issue resolution, and empower customer-facing teams. We are transforming the landscape of customer communications by integrating voice, SMS, WhatsApp, and AI into a unified workspace.Our growth is driven by a straightforward principle: to enable teams to work smarter, not harder. Our AI Voice Agent automates routine calls, while AI Assist simplifies post-call tasks, and AI Assist Pro provides real-time insights, allowing individuals to excel in their roles. This synergy results in increased revenue, quicker resolutions, and scalable teams.Headquartered in Paris, with a solid presence in North America anchored in Seattle, Aircall also has teams in vibrant cities such as Madrid, London, Berlin, San Francisco, New York City, Sydney, and Mexico City. Our product is beloved by customers, and we are rapidly scaling, supported by top-tier investors and continuous AI advancements across multiple product lines.At Aircall, you'll become part of a dynamic company. We are ambitious, focused on product development, and execution-oriented, with a clear impact, swift decision-making, and genuine growth opportunities.Our Work Culture at Aircall: We prioritize customer satisfaction, leverage data for decision-making, and are dedicated to delivering significant outcomes. We cherish ownership, continuous improvement, and thoughtful agility. If you thrive in a collaborative, fast-paced environment where trust and impact are essential, you will thrive here.Position Overview:As a Senior Backend Software Engineer, you will take charge of designing, developing, deploying, and maintaining essential features that enhance customer value on our voice platform.You will be expected to advocate for best practices, mentor team members, and contribute to the broader Engineering community as part of your daily responsibilities.Quality, excellence, and agility are at the core of our delivery process, and you will play a pivotal role in elevating these standards.Utilizing a diverse array of backend technologies tailored to specific needs, all hosted on AWS, we create resilient services that deliver added value on top of voice while fully integrating with our customers' critical business tools (CRM, Helpdesk, E-Commerce, etc.).

About 9fin9fin is a cutting-edge AI platform revolutionizing the global debt markets, which represent the largest asset class exceeding $145 trillion.The landscape of debt markets is extensive, global, and essential, yet it often relies on disjointed data, PDFs, and manual processes. 9fin transforms this outdated infrastructure by providing a unified platform that consolidates proprietary credit data, in-depth analysis, and efficient workflows across international markets.Currently, 9fin empowers over 300 prestigious institutions worldwide, including leading banks, asset managers, private equity firms, law firms, and consulting advisors. The company is experiencing rapid growth, particularly in the US, with exceptional retention rates driven by robust workflow adoption.We are at a pivotal moment. With a validated product-market fit and strong global demand, 9fin is propelling towards becoming the definitive platform for debt markets globally.What You'll Work OnAs a Senior Backend Engineer on our Structured Credit team, you will contribute to the development of our market-leading CLO product and assist in the launch of a new vertical.Our team is dedicated to making a significant impact, leveraging technology to create value for the business. While we have overarching business goals, we enjoy the autonomy to define our team objectives and determine our success metrics. We uphold accountability and proactive behaviors such as ownership.Lead projects within a cross-functional team by defining and designing systems, building proof of concepts, and delivering new service functionalities—including APIs, data processing, and automation—while collaborating with Product and Clients.Engage in backend development and engineering primarily on the services and web applications hosted on the 9fin platform.Play a crucial role within project teams as a senior individual contributor, conducting code reviews, mentoring fellow developers, and participating in early research and experimentation with new technologies to provide insights for new features and products.Continuously enhance the 9fin codebase by seizing opportunities to automate, refactor, and document processes when it has the most significant impact.Work across diverse web platforms involving complex financial data modeling, intricate access control logic, environmental data capture, integration of ML/AI prediction services, and data visualization.

Join commercetools as a Senior Backend Engineer, where you will play a pivotal role in shaping innovative backend solutions using TypeScript. Collaborate with cross-functional teams to create scalable and resilient microservices that empower our clients to deliver exceptional digital commerce experiences.

Corgi provides insurance for technology startups, using AI to streamline underwriting and operations. With $108 million in funding and full regulatory approval as a licensed carrier, Corgi is expanding into the UK and EU. The platform uses Django, integrates Stripe for payments, and relies on AI-driven processes at every stage. Role overview This founding engineer position is based in London and focuses on building and shipping real products. Joining at an early stage, the role involves shaping both the product and company culture as Corgi grows in new markets. The work is hands-on, with a strong emphasis on delivering live solutions rather than just planning or design. Requirements Track record of independently building and launching projects with real user engagement and polished outcomes Comfort working at a daily pace, prioritizing progress over prolonged planning Ability to work across the technology stack and solve problems directly Strong opinions, balanced by openness to better solutions Humble attitude and genuine drive to build and improve How Corgi works Decisions are made quickly, without waiting for perfect answers Products and improvements are released regularly, not just quarterly Ship-and-iterate mindset keeps momentum high and avoids bureaucracy Consistent intensity during product pushes, with minimal slowdowns Decisions are made transparently High performers help raise the bar for the team This is not a passive or comfortable position. The role suits those who want to build and take ownership. Behaviors that lead to removal Engaging in office politics, avoiding responsibility, or gossiping Treating direct feedback as a personal attack Adding unnecessary complexity instead of improving efficiency Missing deadlines after making commitments How to apply Instead of a resume, send links to your work, such as: GitHub repositories Personal website Live projects Shipped applications Email applications to: sergio@corgi.com Candidates must have demonstrable projects to share. If not, this role is not a fit. Location This position is based in London. On-site or hybrid work options are available. Compensation Salary ranges from £75,000 to £140,000, plus equity. The range reflects a focus on real shipping ability over job titles.

About the CompanyAffinidi is a pioneering technology firm focused on reimagining data ownership. We empower both businesses and individuals to take control of their data, providing a holistic approach to managing their digital identity while prioritizing privacy and security.Our innovative technology facilitates decentralized digital identity solutions, ensuring that everyone has the right to own and govern their data. We are dedicated to establishing a trustworthy ecosystem for digital credentials that allows secure data and service exchange across various sectors and borders. About the Role: We are seeking a solution-driven Senior Backend Engineer who possesses substantial expertise in Rust. The ideal candidate will have a track record of delivering robust backend solutions and is eager to contribute to our mission of transforming digital identity.

Join Our Dynamic Team at XapienAt Xapien, we empower businesses to truly understand their connections with suppliers, investors, partners, and third parties. Our innovative approach merges speed, scale, and precision, utilizing advanced AI technology.Since our inception in 2018, we've evolved from a deep-tech startup to a key player in AI-driven due diligence and risk intelligence. The year 2024 marked a significant milestone, with the successful closure of a $10M Series A funding round and accolades in the Chartis RiskTech100® and Everest Group’s Leading 50™. Our expansion has led to a broader product range, new market entries, and an expanding customer base.Our Growth TrajectoryWe're witnessing accelerated demand across various industries, especially in wealth management, financial services, and supply chain onboarding, extending our reach beyond the UK to customers in the Middle East, Asia, and Oceania.Why Now is the Perfect Time to Join UsThis position is not just another role; it’s a chance to influence the future of the due diligence sector with a market-leading product that organizations worldwide trust. Whether your expertise lies in marketing, communications, sales, or finance, your contributions will be vital in driving growth, enhancing credibility, and connecting our product with a swiftly changing market.As we scale rapidly, with an increasing number of customers and product releases, we face larger regulatory and market challenges. The expectation for real-time insights in due diligence is higher than ever. Your role will go beyond routine tasks; you will be shaping strategy, refining processes, and positioning a brand that is redefining trust and transparency.If you're passionate about learning, innovating, and making a meaningful impact, now is the time to join Xapien.The RoleWe are seeking a skilled Senior Backend Engineer to take on a pivotal technical leadership role within our engineering team. You will tackle our most complex technical challenges, take ownership of critical components within our platform’s architecture, and help guide our technical direction to ensure we continue to stay ahead in the industry.

About UsAre you ready to embark on a thrilling challenge?At XYZ Reality, a dynamic and award-winning Series-A startup, we're on a rapid ascent toward our next funding milestone. Our vision is to revolutionize the construction sector by enhancing our platform's features, performance, and scalability.We thrive in a fast-paced, multi-disciplinary environment, engaging in various domains such as cloud development, electronics, embedded software/hardware, mechanical design/manufacturing, AI & computer vision, and data science—all contributing to our innovative BIM Platform.To propel this mission forward, we are in search of a Backend Engineer with extensive Node.js experience to assist in our transition from Java to Node.js and develop high-performance, scalable backend services. You will collaborate closely with our API development, client applications, and data pipeline teams to design and deliver robust, efficient solutions.Our office is situated in central London, just a short stroll from Angel Station.

We are seeking an experienced and passionate Senior Backend Engineer specializing in TypeScript to join our dynamic software engineering team at onrunning. In this pivotal role, you will lead the design and development of robust backend systems that power our innovative applications. You will collaborate closely with cross-functional teams to deliver high-quality solutions that meet the needs of our users. If you have a strong background in backend development, a love for building scalable systems, and a desire to drive technical excellence, we want to hear from you!

Your RoleAs a Founding Engineer at Marloo in London, you will play a pivotal role in shaping the future of our product. Your responsibilities will include:End-to-End Full-Stack DevelopmentOwn and develop core product features, working seamlessly from backend infrastructure to engaging frontend experiences, prioritizing rapid delivery and continuous iteration.Architectural LeadershipEstablish sustainable technical patterns and make crucial architectural decisions that align with our growth trajectory. You will be the guiding authority on our codebase and influence our engineering culture significantly.Collaborative Product DevelopmentEngage directly with the founders to convert user feedback into innovative technical solutions. Your understanding of business needs and product development will be as essential as your technical skills.AI-Driven DevelopmentUtilize AI tools daily to enhance your development processes, from architecture to debugging. We expect you to be an adept user of the latest AI development technologies.

Join Our Vision! At Uncapped, we empower ambitious founders to scale their businesses through innovative financing solutions. We champion curiosity, continuous improvement, and impactful problem-solving.Technologies You Will Work With Core Technologies: Java 21, Spring Boot/Cloud 3.3Infrastructure: GCP, KubernetesDatabase Technologies: SQL/NoSQL (chosen per use case)Your Contributions Design and develop secure microservices tailored for financial systems.Take ownership of services throughout their lifecycle (design → deploy → monitor).Enhance code quality through automation and modern practices (CI/CD pipelines in under 15 minutes).Stay at the forefront of technology and share your insights with the team.Excel within a Kanban-driven team that values effective communication over meetings.Why Choose Uncapped?Be part of a fintech solution trusted by thousands of businesses.Contribute to a product that you can help shape and significantly impact.Supported by leading venture capitalists like LakeStar and SeedCamp.

Affinidi develops technology that helps people and organizations manage their data with greater control. The team designs digital identity tools that keep privacy and security at the forefront. Their work emphasizes decentralized approaches, aiming to make digital credentials both secure and accessible across industries and borders. Role overview The Senior Backend Engineer (Rust) position focuses on building and refining backend systems for privacy-first digital identity products. This London-based role plays a key part in supporting secure, reliable services that underpin Affinidi's core offerings. What you will do Develop and maintain backend services using Rust Create technical solutions that enhance efficiency and reliability Support the ongoing development of decentralized identity platforms Location London, England, United Kingdom

Corgi is a licensed insurance carrier focused on tech startups, using AI to simplify and speed up coverage. The company has raised $108M and is expanding across the UK and EU. The platform relies on Django, integrates Stripe for payments, and features AI-driven underwriting. Role overview This founding engineer role is based in London and centers on building and launching new products, often independently. Corgi values engineers who turn ideas into live products, rather than following detailed roadmaps. Evidence of shipped side projects, weekend builds, or products that have reached real users is highly regarded. Who succeeds here Track record of independently building and delivering real projects Comfortable working across the full technology stack Delivers results quickly, in hours or days Low-ego, motivated by results rather than titles Open to feedback and willing to adopt better ideas Thrives in a high-energy startup setting How we work Decisions are made quickly; perfection is not the goal Products and processes ship regularly, not just quarterly Iteration happens after shipping, not after long review cycles High intensity during launches, with a steady pace year-round Transparent decision-making; no closed-door policies Internal competition is encouraged to raise standards This is a hands-on role for builders who want to make things happen. Behaviors that don’t fit Office politics, gossip, or avoiding responsibility Taking direct feedback personally instead of constructively Adding unnecessary overhead instead of streamlining Missing deadlines after committing to them Application process Send links to your GitHub, personal website, live projects, or shipped products CVs are not accepted Email applications to: sergio@corgi.com Evidence of shipped work is required for consideration Location and compensation Role is based in London; on-site or hybrid arrangements available Base salary: £75,000–£140,000, plus equity Salary band reflects proven shipping ability, not job titles

Role overview airapps is hiring a Backend Engineer for its London Metropolitan Area team. This role focuses on designing and building scalable server-side applications that support the company’s products and services. What you will do Work closely with colleagues across different functions to develop backend systems Contribute to the architecture and implementation of server-side features Help ensure backend solutions can scale and perform reliably Location This position is based in the London Metropolitan Area.

Transform the Future of Finance.At Light, we are revolutionizing the outdated ERP systems of the factory era with innovative software that feels dynamic and responsive. Our Smart Financial Platform empowers modern, global enterprises with automated accounting, instantaneous reporting, and financial processes that adapt to the pace of business.We're passionate about collaborating with our clients, delivering swiftly, and perfecting our craft. In a short span, Light has evolved from a concept to an essential operational tool for renowned companies such as Lovable, Legora, and Keyshot. Our users don’t just utilize Light—they genuinely enjoy the experience.As a pioneering team, we are establishing a new software category. We are looking for engineers who appreciate the intricacies of debits and credits, designers who prioritize reconciliation states, and operators who view finance as a product. If you are eager to modernize the financial landscape—one workflow at a time—you belong here.Supported by prestigious investors and guided by industry leaders, we are crafting products that define categories, allowing us to innovate boldly and take ownership of our results. Join us in our mission to make Light the global standard for next-generation financial solutions.Your Role as a Backend Engineer:Enhance our core Smart Financial Platform, enabling multinational corporations to streamline their accounting processes through AI and exceptional user experience.Maintain a strong focus on customer requirements while architecting robust and scalable technical solutions.Develop and optimize backend services, APIs, and infrastructure to support our high-performance frontend applications.

About XapienAt Xapien, we redefine the landscape of due diligence by empowering businesses with essential insights about their suppliers, investors, partners, and third parties. Our innovative approach integrates speed, scale, and precision through advanced AI technology.Since our inception in 2018, we have evolved from a deep-tech startup into a significant global player in AI-enhanced due diligence and risk intelligence. The year 2024 marked a pivotal moment for us, as we secured a $10 million Series A funding, achieved accolades in the Chartis RiskTech100® and Everest Group’s Leading 50™, and broadened our product offerings and market reach.Looking ahead to 2025, we are poised for even greater achievements. As organizations face mounting compliance demands and heightened reputational risks, they are increasingly seeking intelligent, efficient solutions—turning to Xapien for rapid, reliable insights that transform days of manual research into actionable intelligence in mere minutes.Our Growth JourneyWe are proud to serve customers across a multitude of industries, with notable expansion in wealth management, financial services, and supply chain onboarding. Our reach extends beyond the UK, with a growing clientele in the Middle East, Asia, and Oceania.Why Join Us Now?This role offers a unique opportunity to influence the future of the due diligence industry with a leading product that global organizations trust. Regardless of your background—be it marketing, communications, sales, or finance—you will play a vital role in driving growth, enhancing credibility, and connecting our product with an ever-evolving market landscape.As we scale rapidly, with increasing customer demand, product releases, and complex regulatory challenges, the stakes are higher than ever. Due diligence now demands instantaneous insights that are delivered effectively and impactfully. Your contributions will transcend traditional roles, as you will help shape strategies, refine processes, and elevate a brand that is setting new benchmarks for trust and transparency.For those passionate about learning, innovating, and making a significant impact, now is the perfect time to join Xapien.The PositionWe are in search of a Senior Backend Engineer to become a pivotal member of our engineering team, tackling some of our most complex technical challenges. You will be responsible for owning critical components of our platform’s architecture, driving innovation and quality in our backend systems.