About the Team Hopper's Fintech Foundation team sits at the centre of the company's mission: reshaping how more than 100 million monthly active users experience travel. It owns the pricing engine that balances customer demand against financial risk across dozens of partners — including Capital One, Air Canada, and Spirit Airlines. About the Role As a Software Engineer on the Fintech Foundation team, you will design, build, and evolve the machine learning systems that power Hopper's pricing engine. You will work closely with the Data Science, Engineering, and Product teams to deliver pricing solutions that are reliable, scalable, and oriented toward commercial outcomes.
Design and implement automated, reusable training pipelines to ensure consistent, scalable model delivery across the partner portfolio
Build ETL pipelines with thoughtful feature engineering to guarantee clean, reliable inputs for pricing models
Monitor production systems for latency, drift, and training-serving skew, optimising continuously to maintain model integrity




Run champion-challenger tests on pricing and product construction levers to surface improvements and respond to shifting market conditions
Partner with data scientists, engineers, and product stakeholders to translate business needs into well-scoped technical solutions
Proficiency in Python, Scala, and SQL, applied to production ML systems rather than exploratory work
~ Experience in data modelling, software architecture, and distributed data processing frameworks at scale
~ Deep understanding of ML algorithms and when to apply them in the context of pricing, demand forecasting, or similar commercial domains
~ A product mindset that keeps the customer outcome in view, even when the work is deeply technical
~ Clear, collaborative communication skills that hold up across data science, engineering, and business stakeholder audiences

Hopper covers the cost of employee premiums for private medical and dental coverage.
Access to co-working s

📌 Senior Software Engineer (Madrid)
🏢 Hopper
📍 Madrid