Senior ML Engineer (PyTorch)

Location: Hybrid in Helsinki, Finland, or Paris, France

Company

hirify.global creates mobile games and consumer apps, including an advertising network powered by first-party data and machine learning.

What you will do

• Own high-visibility machine learning infrastructure projects from scoping and architecture design through production release.
• Build and optimize data and ML training pipelines for performance, memory efficiency, cost, and scalability.
• Provide reusable, tested pipeline components and dataset capabilities that enable faster data scientist iteration.
• Develop deep learning infrastructure, including GPU orchestration, custom PyTorch training loops, and model architecture support.
• Maintain reproducible ML workflows through versioned configurations, experiment tracking, and online-offline consistency tooling.
• Collaborate with infrastructure and product teams, participate in alert triage, and mentor engineering teammates.

Requirements

• 5+ years of experience as an ML Engineer or in a similar role.
• End-to-end ownership of ML problems, including framing, experimentation, deployment, and iteration.
• Strong Python experience for preprocessing, training and evaluation workflows, experiment utilities, and reproducible configurations.
• Practical experience with scikit-learn, LightGBM, and PyTorch, including custom training mechanics and performance-conscious data loading.
• Experience with memory optimization, hyperparameter tuning, experiment tracking, model serving, and production ML challenges such as feature stores and training-serving skew.
• Experience with Amazon Web Services and familiarity with scalability, reliability, and security topics. Excellent English communication skills required.

Nice to have

• Experience with real-time or batch model serving and latency or throughput optimization.

Culture & Benefits

• Fast-paced agile environment with rapid decision-making.
• Daily collaboration with backend developers, data scientists, infrastructure engineers, and product managers.
• Knowledge sharing, mentorship, and an inclusive engineering culture.
• Benefits vary depending on the country of residence.