Data Scientist

Location: Krakow, Poland; Krosno, Poland; Lublin, Poland; Poland; Poznan, Poland; Warsaw, Poland Workplace: remote At TechBiz Global, we provide recruitment services to top clients from our international portfolio. We are currently looking for a Senior Data Scientist with strong hands-on experience in training AI models, particularly Large Language Models (LLMs) and Small Language Models (SLMs), using GPU infrastructure and real-world datasets . The ideal candidate should be based in Poland and able to clearly demonstrate their technical expertise, explain the tools and frameworks they use, and describe the complete model-training process—from data preparation to deployment and performance optimisation. Key Responsibilities Train, fine-tune, and optimise LLMs and SLMs using GPU infrastructure. Build and manage end-to-end machine learning training pipelines. Prepare, clean, structure, and process large volumes of real-world data. Select appropriate models, frameworks, tools, and training approaches based on project requirements. Apply techniques such as supervised fine-tuning, transfer learning, prompt tuning, and parameter-efficient fine-tuning. Monitor model performance and improve accuracy, speed, scalability, and resource utilisation. Work with structured, unstructured, time-series, telemetry, log, and streaming data. Clearly document and explain the tools, methods, and technical decisions used throughout the model-training process. Collaborate with engineering, data, and business teams to move models from experimentation into production. Troubleshoot issues related to model quality, training stability, GPU performance, and data pipelines. Proven professional experience as a Data Scientist, Machine Learning Engineer, AI Engineer, or similar role. Strong hands-on experience training or fine-tuning LLMs and/or SLMs. Practical experience using GPUs for AI model training. Strong Python programming skills. Experience with machine learning and deep-learning frameworks such as: PyTorch TensorFlow Hugging Face Transformers Experience with GPU-related technologies and environments, such as CUDA, distributed training, cloud GPU platforms, or GPU clusters. Strong understanding of model-training workflows, including data preparation, tokenisation, model selection, training, evaluation, and optimisation. Ability to clearly explain previous AI projects, tools used, technical challenges, and achieved results. Experience working with large and complex datasets. Good English communication skills. Based in Poland. Relevant Industry Experience Experience in one or more of the following industries or data environments would be highly valuable: E-commerce Finance or banking Insurance Healthcare or medical data Telemetry and IoT data Application or system logs Real-time and streaming data High-volume enterprise data environments Nice to Have Experience with distributed model training. Experience with LoRA, QLoRA, PEFT, quantisation, or model compression. Experience with MLOps tools and model deployment. Knowledge of Docker, Kubernetes, MLflow, or similar technologies. Experience using AWS, Azure, or Google Cloud for AI workloads. Experience deploying AI models into production environments. Knowledge of data privacy, security, and governance requirements.