Lead Machine Learning Engineer – Recommendation Systems at grai

Department: R&D

Language

Setup: Hybrid
Location: Poland
Level: lead/mgmt
Posted: Jul 1, 2026

Description

GRAI is hiring a Lead Machine Learning Engineer to architect, build, and scale recommendation and discovery engines for its social music app. The role owns the technical roadmap for the RecSys stack, including retrieval, ranking, re-ranking, ML infrastructure, MLOps, real-time monitoring, offline evaluation, and A/B testing, while mentoring ML engineers and collaborating with Product and Engineering. Candidates need extensive experience with production recommendation systems, large-scale ranking models, distributed data systems, modern ML frameworks, and low-latency production deployments.

Required Skills

Recommendation systems
Deep learning
Information retrieval
PyTorch
TensorFlow
MLOps
A/B testing
Graph neural networks

Additional Information

Required Previous Experiences: Extensive experience designing, building, and scaling production-grade recommendation systems, search engines, or large-scale ranking models
Significant experience with distributed data systems and modern ML frameworks, including PyTorch and TensorFlow
Strong experience deploying and maintaining low-latency models in production, including feature stores, model registries, and drift monitoring
Experience leading technical projects, mentoring engineers, and managing stakeholders while maintaining hands-on technical involvement
Preferred Qualifications: Experience with streaming data architectures and real-time or session-based recommendation systems
Background in audio processing, music streaming, or high-growth consumer-facing personalization products
Familiarity with graph neural networks, reinforcement learning, or large language models for recommendation context