Senior Machine Learning Engineer (all genders) - Babbel Labs

Hands-on senior individual-contributor ML engineer on Babbel Labs' learner-personalisation team, which tracks what learners have mastered and decides what they should practice next. You will own core personalisation and mastery-tracking subsystems end to end, working with the Principal Scientist to take designs from spec into production and shaping new features from the start. The role includes designing rigorous offline benchmarks and online experiments, instrumenting and running what you build, and delivering with coding agents. It suits an engineer with production ML experience in recommendation, ranking or scoring systems and a strong grounding in probabilistic and Bayesian modeling.