Senior Data Scientist (LLM)

About Multiverse Computing

Multiverse is a well-funded, fast-growing deep-tech company founded in 2019. We are the largest quantum software company in the EU and have been recognized by CB Insights (2023 and 2025) as one of the 100 most promising AI companies in the world.

With 180+ employees and growing, our team is fully multicultural and international. We deliver hyper-efficient software for companies seeking a competitive edge through quantum computing and artificial intelligence.
Our flagship products, CompactifAI and Singularity, address critical needs across various industries:

• CompactifAI is a groundbreaking compression tool for foundational AI models based on Tensor Networks. It enables the compression of large AI systems—such as language models—to make them significantly more efficient and portable.
• Singularity is a quantum- and quantum-inspired optimization platform used by blue-chip companies to solve complex problems in finance, energy, manufacturing, and beyond. It integrates seamlessly with existing systems and delivers immediate performance gains on classical and quantum hardware.

You’ll be working alongside world-leading experts to develop solutions that tackle real-world challenges. We’re looking for passionate individuals eager to grow in an ethics-driven environment that values sustainability and diversity.

We’re committed to building a truly inclusive culture—come and join us.

Position

We are seeking a Senior Data Scientist with deep expertise in creating high-quality datasets for training and fine-tuning Large Language Models (LLMs). You will be responsible for designing and implementing scalable data pipelines and strategies to support all stages of LLM development: pretraining, supervised fine-tuning, and reinforcement learning with human feedback (RLHF).

This role is critical to ensuring the robustness, safety, and alignment of our AI models. You will have the autonomy to explore innovative data sourcing and curation methods and the opportunity to directly influence the capabilities of state-of-the-art LLMs.

As a Senior Data Scientist, you will:

• Design and implement strategies for creating, sourcing, and augmenting datasets tailored for LLM training and fine-tuning.
• Develop scalable pipelines to collect, clean, filter, annotate, and validate large volumes of text data.
• Conduct data audits to ensure quality, diversity, ethical compliance, and bias mitigation.
• Collaborate with ML engineers and researchers to align datasets with training objectives and model evaluation needs.
• Use tools like Active Learning, synthetic data generation, and self-supervised learning to maximize dataset efficiency.
• Leverage human-in-the-loop (HITL) workflows for data labeling and validation where necessary.
• Contribute to building data documentation and metadata standards (e.g., Datasheets for Datasets).
• Keep up to date with research trends in dataset curation, LLM pretraining data, and benchmarking.

Your qualification

Required qualifications:

• Bachelor’s, Master’s, or Ph.D. in Computer Science, AI, Data Science, or a related field.
• 3+ years of experience in data science, machine learning, or related roles, with demonstrated experience in dataset creation for NLP or LLMs.
• In-depth knowledge of the LLM lifecycle: pretraining, fine-tuning, alignment, and evaluation.
• Proficient in Python and data tooling ecosystems (Pandas, NumPy, spaCy, Hugging Face Datasets & Transformers).
• Hands-on experience with text data collection from diverse sources: web scraping, APIs, proprietary corpora, etc.
• Strong understanding of data quality metrics, including bias detection, toxicity, and readability.
• Experience working with annotation tools (e.g., Prodigy, Label Studio) and managing annotation teams or workflows.

Preferred qualifications:

• Experience building or contributing to datasets used in LLM pretraining or supervised fine-tuning.
• Familiarity with RLHF workflows and alignment techniques (e.g., preference modeling, reward modeling).
• Exposure to multilingual and low-resource language datasets.
• Contributions to open-source datasets, tools, or publications in dataset-centric research.
• Knowledge of ethical AI, data governance, privacy laws (e.g., GDPR), and responsible data use.

What we offer

• Indefinite contract
• Equal pay guaranteed
• Variable performance bonus
• Signing bonus
• We offer work visa sponsorship (If applicable)
• Relocation package (if applicable)
• Private health insurance
• Eligibility for the educational budget according to internal policy
• Hybrid opportunity
• Flexible working hours
• Language classes and discounted lunch options
• Working in a high-paced environment, working on cutting-edge technologies
• Career plan. Opportunity to learn and teach.
• Progressive company. Happy people culture

Additional details

As an equal opportunity employer, Multiverse Computing is committed to building an inclusive workplace. The company welcomes people from all different backgrounds, including age, citizenship, ethnic and racial origins, gender identities, individuals with disabilities, marital status, religions and ideologies, and sexual orientations to apply.