.At Preply, we are unlocking human potential through learning.We believe learning with a great tutor is life-changing. That's why we match online tutors from across the globe with learners and empower them to create live language classes with AI-powered tools and learning materials. This is how we deliver progress, create engagement and keep our global community of learners motivated. So far, over 32,000 tutors have given more than 15 million lessons to learners from over 175 countries.Meet the team!We A/B test mostof our changes on production, both product and technical, before scaling it to all customers. The Experimentation Squad owns the whole infrastructure and the framework that are used to make those business-vital decisions.We define the framework, including the overall evaluation criteria, set of target metrics, and available test types: student-sided, tutor-sided, clustered; frequentist, bayesian, interleaving; superiority, non-inferiority. We analyze performance of the experimentation program using multiple holdout groups and push product management in the right direction. Finally, we're in charge of improving the company's experimentation culture and education, and keeping institutional memory.We have diverse technical challenges (sometimes we write about them on our Engineering Blog) that will allow you to develop your skills across the stack. Visit our Tech Radar to learn more about the technologies we use at Preply!What you'll be doing:Unlock the potential of product and marketing teams by researching and implementing new approaches for hypothesis testing (clustering, interleaving, geolift,..); Identifying and designing value-adding insights solutions, leveraging data to optimize our strategy; Establish credibility and quality of the experimentation framework; Quantify the impact of product and marketing development and distinct initiatives in order to identify growth opportunities and help top management in prioritizing Preply's roadmap; Level up the experimentation culture across the company; Support engineers to build and maintain high-quality data pipelines; Collaborate with productteams to help them tackle technical issues with A/B testing; Collaborate with marketing teams to measure the impact of changes in budget relocation