Senior Full Stack Engineer

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're also 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 and an international environment.

For more information about our company and our team, visit our careers page at

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 significantly in AI to enhance our product with real use cases, and you'll play a key role in building our AI foundations.

We work in continuous deployment (10 deploys in production per day on average) and we value pragmatism, ownership, and growth mindset.

For more information about how we operate in the engineering team, please read this article.

In your day-to-day, you will:

• 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 us define and improve our coding standards, development processes, and best practices.
• Stay up to date on new technologies and promote their adoption when appropriate.

• Frontend: Typescript, React, GraphQL
• Backend: Typescript, , Express, Postgres, and Redis
• Infra: GCP, Terraform
• Observability: Datadog and Sentry
• Github, Copilot, Claude Code, CircleCI

• 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 in order 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 Paris timezone.

Top-market compensation + company's equity — €60k/yr - €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 strong 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.

1 - Screening call

It's a discussion with your future manager. We'll get deeper into your expertise and know-how. We'll also give you a clearer view of what your day-to-day in that role is like. It's a good opportunity to see if you foresee yourself working at Upflow.

2 - Technical interviews

System design interview

In this interview, we'll explore how you design scalable systems and make architectural decisions. You'll be presented with a real-world scenario and we'll discuss trade-offs, data modeling, and how you'd handle scale and reliability.

React Coding interview

This is a pair-programming session where you'll work through a real-world problem similar to what you'd encounter at Upflow. We'll collaborate on solving it together, giving us insight into how you approach technical challenges and communicate your thought process.

4 - Meet the team

You'll also meet up with at least two other peers so you can foresee yourself as part of this team.

5 - Founder interview

Meet with Alex (co-founder & CEO). He will tell you everything about Upflow's vision and values. It's a privileged moment to ask questions, too.

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. Research shows that some candidates may hesitate to apply unless they meet every requirement. However, we believe that a variety of experiences and perspectives can bring value beyond the listed qualifications. If you're excited about what we do and feel you could contribute, we want to hear from you