Senior Full Stack Engineer

Join to apply for the Senior Full Stack Engineer role at Upflow About Upflow Upflow provides cutting-edge cash collection technology to help B2B companies get paid faster and simpler. We are a product‑led SaaS startup launched in 2018 and trusted by hundreds of companies across the US and EMEA, including Lattice, ProductBoard, Instawork and more. We are backed by leading investors (YCombinator, Hexa, Hedosophia) and top business angels from N26, Square, Mercury, Uber and NetSuite. This is an amazing opportunity to work and learn in a fast‑growing fintech in an international environment. About The Role You will join a small, efficient team based in Paris or working remotely that builds high‑impact features for our users. You'll work on a wide range of topics, including workflow automation, payment processing, and communication features like email, calls, and letters. We invest heavily in AI to enhance our product and you will play a key role in building our AI foundations. We work in continuous deployment (about 10 deploys in production per day) and we value pragmatism, ownership, and a growth mindset. What You Will Do Architect and implement complex, high‑impact product features from start to finish. Collaborate closely with the product manager, the designer, and other engineers to translate business requirements into technical solutions. Ship clean, maintainable code to production daily. Participate actively in code reviews, providing and receiving constructive feedback. Troubleshoot and debug complex product issues. Optimize application performance and ensure scalability. Help define and improve coding standards, development processes, and best practices. Stay up to date on new technologies and promote their adoption when appropriate. Our Current Stack Frontend: TypeScript, React, GraphQL Backend: TypeScript, Node.js, Express, Postgres, and Redis Infrastructure: GCP, Terraform Observability: Datadog and Sentry Tools: GitHub, Copilot, Claude Code, CircleCI Who You Are You have 5+ years of experience in software engineering. You have strong proficiency in TypeScript, React, and SQL. You value code simplicity and testing. You know how to prioritize to deliver quickly without sacrificing quality. You have good teamwork skills and enjoy providing and receiving feedback. You want to work in a startup environment that values excellence, autonomy, and ownership. You are fluent in English with strong communication skills. You are based in Paris or live in the Paris time zone. Why Join Upflow? 💰 Top‑market compensation plus equity — €60k/yr to €90k/yr. 🚀 Best‑in‑class product in a massive market. 💨 Fast‑moving environment — you will never stop learning and growing. 🤝 Trusting environment — hands‑off management style with a culture of ownership and autonomy. 🌎 International environment — work with team members across Europe and the US. ✈️ Exchange program — opportunity to work from New York for 4 weeks a year. 🏢 Flexible remote culture with offices in Le Marais. 🤼 Team activities such as lunch, drinks and offsite organized regularly. Recruitment Process 1 - Screening call It’s a discussion with your future manager. We’ll dive deeper into your expertise and give you a clearer view of the day‑to‑day in this role, helping you decide if you see yourself at Upflow. 2 - Technical interviews • System design interview – we explore how you design scalable systems and make architectural decisions using a real‑world scenario. • React coding interview – a pair‑programming session where you solve a realistic problem, allowing us to see how you approach challenges and communicate your thought process. 3 - Meet the team You’ll meet at least two other peers to see if the team feels right for you. 4 - Founder interview Meet Alex, co‑founder & CEO. He shares the vision and values, and you discuss the fit. At Upflow, we are committed to building a diverse and inclusive workplace. We encourage all individuals to apply, even if you don’t meet every qualification. We believe that a variety of experiences and perspectives can bring value beyond the listed qualifications. Referrals increase your chances of interviewing at Upflow by 2x. #J-18808-Ljbffr