Senior Applied Data Scientist | NDA

    Warsaw, Poland
    Full-Time
    Senior (7+ yrs)
    Data & Analytics
    Posted on August 31, 2026

    GT was founded in 2019 by a former Apple, Nest, and Google executive. GT’s mission is to connect the world’s best talent with product careers offered by high-growth companies in the UK, USA, Canada, Germany, and the Netherlands.

    On behalf of our client, GT is looking for a Senior Applied Data Scientist interested in developing and testing new ML, embedding, and LLM-based approaches to solve complex data matching problems at scale.

    About the Client

    Our client is a leading global management consultancy known for tackling some of the world’s most complex business challenges. With a focus on strategy, transformation, and performance improvement, the firm partners with major organizations across industries to drive lasting impact.

    About the Role

    We are looking for a Senior Applied Data Scientist to improve how entity resolution is performed at scale.

    You will develop and test new ML, embedding, and LLM-based approaches for matching complex business records across multiple data sources.

    The work is centered on model quality, experimentation, and evaluation; engineering partners will help productionize successful approaches.

    A key part of the role is exploring how newer foundation-model techniques can improve matching quality while remaining practical and scalable for very large datasets.

    Responsibilities:

    Develop better ways to match company records

    • Build new ML, embedding, and LLM-based approaches for matching entities

    • Improve how the system handles messy data, including name variations, aliases, domains, websites, firmographic attributes, multilingual records, and data hierarchies.

    • Develop scoring and ranking approaches to distinguish accurate matches from duplicates, similar-looking records, and unrelated entities.

    • Evaluate and implement AI and machine learning techniques to improve matching quality while considering accuracy, scalability, and cost.

    • Design approaches that can operate efficiently at scale, taking model usage and computational cost into consideration.

    Improve evaluation, experimentation, and match quality

    • Define and improve methods for evaluating match quality, including precision, recall, false positives, false negatives, confidence, coverage, and manual review effort.

    • Assist in building trusted benchmark sets that allow us to compare new models against the current matching engine before production rollout.

    • Explore LLM-assisted review and validation to assess matching performance and benchmark more scalable approaches.

    • Turn ambiguous matching problems into clear hypotheses, experiments, metrics, and recommendations.

    Partner with engineering to bring successful ideas into production

    • Work closely with data engineering and software engineering teams to turn promising prototypes into production-ready matching logic.

    • Provide engineering partners with clear model specifications, evaluation results, expected behavior, edge cases, and rollout requirements.

    • Help determine the most appropriate matching techniques based on data characteristics, confidence levels, and cost considerations.

    • Continuously evaluate matching performance, investigate regressions, and recommend improvements to models and matching logic.

    • Clearly communicate technical tradeoffs related to matching performance, scalability, cost, latency, explainability, and operational considerations.

    Essential knowledge, skills & experience:

    • 5–8 years of relevant experience in Data Science, Applied Data Science, Applied Machine Learning, or a similar role.

    • Strong applied ML fundamentals, with hands-on experience building and evaluating models on real data.

    • Excellent Python and SQL skills.

    • Practical experience with embeddings, semantic similarity, LLMs, or related AI techniques.

    • Hands-on experience training supervised and unsupervised models, including classification and NLP tasks.

    • Working knowledge of neural network and transformer architectures.

    • Proficiency with common ML frameworks such as TensorFlow, PyTorch, and PyCaret.

    • Experience retraining a taxonomy classifier or maintaining classification models in production.

    • Experimental judgment: able to define baselines, metrics, test sets, and error analysis that show whether quality improved.

    • Ability to explain model behavior, tradeoffs, and edge cases clearly to engineering and business partners.

    Nice-to-have:

    • Experience with entity resolution, record linkage, deduplication, or similar matching problems.

    • Experience with ranking, similarity scoring, retrieval, clustering, or candidate generation.

    • Experience applying LLMs or embeddings to business problems where cost and scale matter.

    • Exposure to large-scale data platforms such as Spark, Snowflake, Databricks, or BigQuery.

    • Familiarity with company, domain, website, firmographic, or other business-entity data.

    Interview Steps:

    1. GT interview with Recruiter

    2. Technical interview

    3. Final interview

    Company:  GT

    Boutique tech partner helping high-growth companies design, build, and scale digital products.
    51-200 employees
    Software & IT Services
    HQ: Ukraine