Senior Machine Learning Engineer

Job Description

Machine Learning Engineering at SIXT turns models into systems that decide prices, forecast demand, and steer a fleet of hundreds of thousands of vehicles, millions of times a day. You build these systems with our Data Scientists, run them in production, and shape the ML platform while it is still being built. The numbers you move are real. Transform the way the world moves, because people expect better. Join Team Orange in Lisbon. 

YOURS TO OWN

• You build ML systems together with Data Scientists, from the first design session to the validated outcome in production. One team, one goal  
• You own design and architecture: how features are computed once and served consistently, how predictions flow out, how training, serving, and retraining fit together  
• You get models live safely - offline evaluation, shadow runs, champion/challenger, rollback. You run what you ship  
• You make quality structural - you define what a healthy ML system looks like, encode it as automated checks and alerts, and root cause issues so they do not recur 
• You are the bridge to MLOps - you bring the team's needs to the platform, bring platform standards back into the team, and co-own the templates and tooling that make the next use case faster 
• You multiply the team - setting the engineering bar, design how coding agents execute the ML lifecycle from data preparation to deployment, and grow production practice together with Data Scientists 

YOUR SKILLS MATTER

• Experience You have shipped and operated ML systems in production for 3+ years and know where they break: training/serving skew, leakage, drift, silent degradation 
• Software Engineering You are fluent in Python, SQL and one more language such as Go or Java: you read, review, and debug production code with confidence, whatever agent wrote it  
• ML Systems Design You design clean contracts between data, model, and consumers and reason about latency, cost, and failure 
• ML Fundamentals You understand forecasting, regression, and optimization well enough to challenge a model design and to recognize a wrong model in production 
• Software Factory You define acceptance criteria, orchestrate coding agents for implementation, QA, and security, and step in where they fall short. You review outcomes, not keystrokes, and want to shape how a team works this way 
• Platform Containers, orchestration, CI/CD, and model registries are daily tools. You have worked hands on in a major cloud platform, ideally AWS. Infrastructure as code is a plus 
• Team Spirit You act as a partner to Data Science, Product and Engineering, not a ticket executor: you challenge unclear framing, explain trade offs in business terms, and communicate fluently in English across cultures

WHAT WE OFFER

• A Global Tech Hub in Lisbon Join a thriving international tech community and work alongside engineers, product experts, and business teams who turn ideas into real impact. Our hubs at Factory Lisboa in Beato and ARTs Lisboa in Parque das Nações are where great tech gets built

• Learning & Knowledge Exchange Level up through regular events with internal and external speakers. We value curiosity, continuous learning, and open exchange – across teams, disciplines, and borders

• Flexible Work Setup Two office days a week, flexible hours, and modern spaces built for both deep focus and team collaboration – work the way that brings out your best

• Time Off & Wellbeing Enjoy 28 vacation days per year, an additional day off on your birthday, one volunteer day annually, and private health insurance that also covers your spouse and children free of charge

• Practical Everyday Benefits Get a yearly Coverflex allowance and a daily meal allowance to make everyday life a little easier

• SIXT Perks Get exclusive rates on all SIXT services, with special discounts extended to your family and friends. Because great perks are even better when you can share them

Qualifications

Additional Information

About us:

We are a globally leading mobility service provider with a revenue of €4.3 billion and around 9,000 employees worldwide. Our mobility platform ONE combines our products SIXT rent (car rental), SIXT share (car sharing), SIXT ride (taxi, ride, and chauffeur services), and SIXT+ (car subscription), giving our customers access to our fleet of 360,000 vehicles, the services of 4,000 cooperation partners, and around 5 million drivers worldwide. Together with our franchise partners, we are present in more than 100 countries at 2,000 rental stations. At SIXT, top-tier customer experience and outstanding customer service are our highest priorities. We believe in true entrepreneurship and long-term stability and align our corporate strategy with foresight. Get started with us and apply now!