Senior Data Scientist Consultant

Keystone Solutions; Brussel Hoofdstad; Hybrid; EUR 90,000 - 130,000; Full time

Job summary

Keystone Solutions is seeking a Senior Data Scientist to join a Brussels-based client engagement as a K-Stone consultant. The role combines on-site work in Brussels (50%) with remote collaboration (50%), within a dynamic Marketing and Communication environment.

You will build and deploy responsible AI models to optimize campaigns, use LLMs for text tasks, and develop end-to-end pipelines. You will present clear, business-ready insights to stakeholders and ensure governance and explainability

Qualifications

• You have at least 5 years of relevant experience.
• Master's degree or higher in statistics, mathematics or computer science.

Responsibilities

• Tackle business challenges by creating responsible AI models for Marketing and Communication.
• Capture business needs, determine feasibility, build models and analyses to identify target groups and set up tests.
• Build models to support customer journey-driven marketing campaigns.
• Build pipelines that structure web analytics and use LLMs to detect customer intent.
• Develop and deploy automated summarization models using LLMs or NLP methods.
• Apply guidelines incl. explainability for building responsible AI models.
• Monitor and deploy AI models in production with a full tooling stack.
• Present technical concepts as clear, actionable insights to business owners and advise on model use in campaigns.

Skills

Python

scikit-learn

transformers

PyTorch

TensorFlow

LLMs for text classification

embedding models

MLflow

experiment tracking

Git

Bash

SQL

Next best action

Customer journey modeling

RAG

Interpretability

Guardrails

Validation

CI/CD

Production deployment

Education

Master's degree or higher in statistics / mathematics / computer science

Tools

MLflow

Git

Bash

SQL

SAS

Streamlit

Job description

Mission Overview:

Keystone Solutions is looking for a Senior Data Scientist for a consultancy mission with a client in Brussels. You will be hired by Keystone Solutions and work as a K-Stone consultant within the client's Marketing and Communication environment, with 50% mandatory on-site presence in Brussels and 50% telework. The Predictive Models team provides responsible AI models that enable impactful and efficient campaigns by optimizing reach and relevance for customers and employees.

Function and Responsibilities:

As a Keystone Solutions consultant, you will join a team of motivated data scientists who are eager to learn, collaborate and share expertise. You will bring a proven track record in building and deploying data science models and expertise in using LLMs for text classification and summarization. Under Keystone Solutions' consultancy model, your responsibilities will include:

• Tackle various business challenges by creating responsible AI models to answer the needs of Marketing and Communication and make campaigns more relevant and impactful.
• Capture business needs, determine feasibility, build models and analyses to identify the most relevant target groups, and set up tests to measure model impact.
• Build models to support customer journey-driven marketing campaigns.
• Build pipelines that clean and structure web analytics and use LLMs to detect customer intent.
• Develop and deploy automated summarization models using LLMs or traditional NLP methods.
• Apply guidelines and best practices, including explainability, for building responsible AI models.
• Monitor and deploy AI models in production using a comprehensive stack of tools.
• Present technical concepts as clear, actionable insights to business owners and advise them on the use of models in campaigns.

Language Requirements:

• Fluent spoken and written English.
• Fluent spoken and written Dutch OR fluent spoken and written French.

Education:

You have a Master's degree or higher in a quantitative field such as statistics, mathematics or computer science. Candidates with other academic backgrounds and substantial experience in data science are also encouraged to apply.

Required Experience and Knowledge:

You have at least 5 years of relevant experience.

Mandatory Technical Experience:

• Expert-level Python programming and expertise in the Python data science environment, including scikit-learn, transformers, PyTorch and TensorFlow.
• Proven ability to fine-tune, evaluate and operationalize LLMs and embedding models for production use in marketing contexts.
• Solid understanding of statistical methods, experiment design and machine learning algorithms, including traditional machine learning and deep learning.
• Expertise in using LLMs for text classification, RAG, interpretability, guardrails and validation of LLM-driven predictions.
• Hands-on experience with MLflow for experiment tracking, model versioning and CI/CD pipelines in AI/ML workflows.
• Expertise in customer journey modeling, such as next best action.
• Experience with Git and Bash.
• Experience with SQL.

Preferred Technical Experience:

• Experience with active learning techniques to iteratively improve models.
• Experience with uplift modeling.
• Experience with Marketing Mix Modeling and optimization under constraints.
• Experience with SAS.
• Experience with Streamlit.

Working Model:

This consultancy mission requires 50% mandatory presence at the client's Brussels office and allows 50% telework. As a Keystone Solutions consultant, you will represent Keystone Solutions at the client site while collaborating closely with client stakeholders and fellow specialists.

Soft Skills:

• Take ownership and demonstrate the ability to drive projects end-to-end with minimal guidance.
• Ability to translate data insights into actionable business recommendations.
• Quick learner and autonomous.
• Clear and concise communication.
• Team player.
• Proactive attitude and results-driven approach.
• Analytical and problem-solving mindset.

Why Keystone Solutions:

As a K-Stone, you bring Keystone Solutions' core values to every engagement while building your consultant identity through meaningful on-site collaboration. Our consultancy model gives you exposure to dynamic projects and diverse challenges across client environments, creating turbo-charged learning through broad technical, business and stakeholder experiences. Keystone Solutions also supports skyrocketing ambition by enabling continued professional development and career growth across challenging consultancy assignments.