About the role
We're looking for a Principal Machine Learning Engineer to join Rent.app, fresh off $125M Series A + B funding. Rent is going through extensive growth and wants to dramatically improve payment optimisation, underwriting, fraud prevention, marketing efficiency and business automation.
Responsibilities
•Set the technical direction and own the full lifecycle of ML systems, from problem formulation and experimentation to deployment and monitoring.
•Build and improve models across underwriting, credit risk, fraud detection, payment routing, collections and marketing optimisation, combining traditional statistical/ML techniques with foundation models and LLM-based approaches.
•Work directly on the underwriting stack, where classical ML and the company's own foundation-model-based systems operate together, and mentor engineers along the way.
Requirements
•Exceptional depth in machine learning, with substantial experience building and operating ML systems in production, including both traditional ML (ranking, classification, tree-based models, calibration) and modern deep learning/LLM systems.
•Strong Python and SQL skills, and experience designing scalable training, inference and model-monitoring infrastructure in a cloud environment.
•AI-native working habits – comfort using modern AI tools to accelerate research, development and experimentation.
•Conversational English.
Nice to have
•Experience in credit underwriting, lending, payments, fraud or financial services is a major plus.
Conditions
•London, UK or Lisbon, Portugal (on-site).
•Up to €220k/year salary + equity; higher figures can be negotiated.
•Official employment, visa and relocation help, supplemental medical coverage, wellness benefits, corp. laptop, etc.
