Senior Machine Learning / LLM Systems Engineer (f/m/x)

Sii Poland; Poznań; On-site; PLN 240,000 - 360,000; Full time

Benefits offered by this job

Great place to work

Profit sharing

Medical care

Internal trainings

Open management

Job summary

Sii Poland is seeking a Senior Machine Learning / LLM Systems Engineer to join our AI platform team in Poland. You will scale and optimize large-scale ML and LLM systems for international clients, collaborating with cross-functional teams on strategic AI initiatives.

The role emphasizes performance engineering, distributed training and inference, and a hands-on approach with C++, CUDA, and Python to push efficiency and reliability across deployments.

Qualifications

• Minimum 5 years of experience with LLM models and ML workloads.
• Hands-on work with large-scale distributed ML systems.
• Low-level optimization skills in C++, CUDA, or similar technologies.
• Strong Python skills with an understanding of system-level performance.
• Very good English skills, both spoken and written.

Responsibilities

• Scale ML and LLM models across multi-node clusters.
• Optimize latency, throughput, and resource efficiency of ML workloads.
• Design and operate distributed training and inference systems.
• Benchmark and profile AI workloads on real hardware platforms.
• Identify and resolve system-level performance bottlenecks.

Skills

LLM models

Distributed ML

C++

CUDA

Python

English

Production ML

Job description

Join Sii and play a key role in delivering enterprise‑class AI platforms to international clients. As a Senior Machine Learning / LLM Systems Engineer, you will be responsible for scaling and optimizing large‑scale ML and LLM systems. You will collaborate with cross‑functional teams and support strategic AI and infrastructure initiatives across the organization.

Your tasks

• Scaling ML and LLM models across multi‑node, multi‑accelerator clusters
• Optimizing latency, throughput, and resource efficiency of ML workloads
• Designing and operating distributed training and inference systems
• Benchmarking and profiling AI workloads on real hardware platforms
• Identifying and resolving system‑level performance bottlenecks

Requirements

• Minimum 5 years of experience with LLM models and Machine Learning workloads
• Strong experience with machine learning in production environments
• Hands‑on work with large‑scale distributed ML systems
• Low‑level optimization skills in C++, CUDA, or similar technologies
• Proven ability to analyze and improve ML system performance
• Solid Python skills with an understanding of system‑level performance
• Very good English skills, both spoken and written

Benefits For You

• Great Place to Work
• Solid financial situation
• Contracts with the biggest brandsCentre of internal trainings
• Many experts you can learn from
• Open and accessible management team
• Profit sharing
• Passion Sponsorship program
• Regular integration events and trips
• Comfortable and well‑equipped offices
• MySii app
• Medical care

Sii ensures that all hiring decisions are made solely on the basis of qualifications and competence. We are committed to equal and fair treatment of all, regardless of legally protected characteristics. At Sii, we promote a diverse and inclusive work environment, in full compliance with applicable anti‑discrimination laws.