Senior Machine Learning Engineer

NTIATIVE IT Recruitment; Warszawa; On-site; PLN 180,000 - 300,000; Full time

Job summary

NTIATIVE IT Recruitment in Warszawa is seeking a Senior Machine Learning Engineer to design, build, and scale core ML systems powering our AI products. This is a hands-on, high-impact role for someone who enjoys solving ambiguous problems, taking ownership, and delivering production-ready ML solutions that create real value for users.

You will own the full lifecycle of ML systems, from data preparation and model training to deployment, monitoring, and continuous improvement.

Qualifications

• Strong proficiency in Python.
• Hands-on experience with PyTorch and/or JAX.
• Experience building GPU-based training and inference systems.
• Track record of designing, building, and deploying ML systems used by real users.
• Ability to write clean, production-quality code.

Responsibilities

• Design, develop, and maintain production-grade ML systems.
• Own the end-to-end ML lifecycle, including data prep, training, evaluation, deployment, inference, and iteration.
• Build robust and scalable training and inference pipelines.
• Translate research ideas into reliable production solutions.
• Monitor, debug, and improve ML models using production signals.
• Optimize models for accuracy, latency, reliability, efficiency, and cost.
• Collaborate with Research, Product, and Engineering teams to deliver AI features.
• Mentor fellow ML engineers through leadership and code reviews.
• Ensure ML systems meet production requirements around scalability and maintainability.

Skills

Python

PyTorch

JAX

GPU training

Production-grade code

Systems thinking

Independent work

Communication

Job description

We are looking for a Senior Machine Learning Engineer to design, build, and scale the core machine learning systems powering our AI products. This is a hands-on, high-impact role for someone who enjoys solving ambiguous problems, taking ownership, and delivering production-ready ML solutions that create real value for users.

You will own the full lifecycle of machine learning systems, from data preparation and model training to deployment, monitoring, and continuous improvement. Working closely with Research, Product, and Engineering teams, you will transform cutting-edge ideas into reliable, scalable production systems.

Responsibilities

• Design, develop, and maintain production-grade machine learning systems.
• Own the end-to-end ML lifecycle, including data preparation, model training, evaluation, deployment, inference, and iteration.
• Build robust and scalable training and inference pipelines.
• Translate research ideas into reliable production solutions.
• Monitor, debug, and improve ML models using real-world production signals.
• Continuously optimize models for accuracy, latency, reliability, efficiency, and cost.
• Collaborate closely with Research, Product, and Engineering teams to deliver impactful AI features.
• Mentor fellow ML engineers through technical leadership, code reviews, and knowledge sharing.
• Ensure ML systems meet production requirements around scalability, performance, safety, and maintainability.

Requirements

• Strong proficiency in Python.
• Hands-on experience with PyTorch and/or JAX.
• Experience building GPU-based training and inference systems.
• Track record of designing, building, and deploying machine learning systems used by real users.
• Ability to write clean, maintainable, production-quality code.
• Strong systems-thinking mindset with the ability to solve complex engineering challenges.
• Self-driven, highly accountable, and comfortable working independently.
• Excellent communication skills and the ability to collaborate across technical disciplines.
• Passion for continuous learning and iterative product development.

Nice to Have

• Experience optimizing ML infrastructure for performance and cost.
• Experience with production model monitoring and observability.
• Familiarity with distributed training and large-scale AI systems.

Why Join Us?

We believe the world's best products are built by small, exceptionally talented teams. We maintain a high-talent-density culture where ownership, collaboration, and execution matter. We move quickly, balancing speed with quality while continuously learning and improving.

You'll have the opportunity to solve challenging technical problems, shape the future of our AI platform, and build products that deliver truly magical experiences for users.