Senior Data Scientist

Make an impact by working in sectors where technology is the enabler and innovation is the key.

At Celfocus, we make data actionable through Next‑Gen Intelligence - where data, AI and human creativity come together.

You’ll work with multidisciplinary teams and partner with leading companies to turn data into decisions, agility and long‑term value.

Explore your way in.

The opportunity:

We are looking for a Senior Data Scientist with strong technical expertise to design, develop, and deploy advanced AI and machine-learning solutions, including Generative AI and Agentic AI systems. In this role, you will be responsible for building high-quality models and data-driven solutions, designing intelligent AI agents and multi-agent workflows, contributing to technical architecture decisions, and ensuring reliable production deployments aligned with best MLOps practices. You will work closely with cross-functional teams to translate business problems into scalable and impactful AI solutions.

Your day-to-day:

• Design, develop, and implement advanced AI and machine-learning models for real-world business problems.
• Define modeling strategies, experimentation approaches, and analytical frameworks for complex AI/ML initiatives.
• Design, develop, and deploy Generative AI and Agentic AI solutions, including AI agents, multi-agent systems, RAG architectures, and agentic workflows.
• Build and optimize AI agents with capabilities such as reasoning, planning, tool usage, and interaction with enterprise data and external systems.
• Leverage data and domain knowledge to deliver impactful, data-driven solutions.
• Collaborate with cross-functional stakeholders to clarify problem statements, gather requirements, and translate them into technical solutions.
• Develop optimization models, experimentation frameworks, forecasting algorithms, and capacity-planning models.
• Ensure robust deployment, monitoring, and lifecycle management of ML, Generative AI, and Agentic AI solutions, following industry-standard MLOps practices.
• Lead and mentor Data Science teams, ensuring technical excellence, timely delivery, and alignment with project goals.
• Contribute to code quality, model validation, and architectural best practices.
• Communicate insights, results, and technical decisions to technical and non-technical stakeholders.

What you'll bring:

• Degree in Computer Science, Engineering, Mathematics, Statistics, Operations Research, or a related analytical field.
• 5+ years of professional experience in Data Science
• Strong expertise in Python and experience with PySpark/Spark MLlib.
• Hands-on experience designing and implementing Generative AI and Agentic AI solutions, including AI agents, agentic workflows, and multi-agent architectures.
• Solid understanding of NLP, text analytics, and unstructured data processing.
• Deep knowledge of ML architectures and MLOps-oriented lifecycles (CI/CD for ML, model versioning, monitoring, retraining pipelines).
• Hands-on experience with NumPy, SciPy, Pandas, Scikit-learn, Matplotlib, TensorFlow/PyTorch.
• Proven track record of leading data science projects end-to-end with MLOps best practices.
• Computer Vision experience in image pre-processing and analysis.
• Strong experience with LLMs, LangChain, RAG (Retrieval-Augmented Generation), prompt engineering, tool/function calling, and production deployment of LLM-based applications.
• Experience designing AI agents with capabilities such as reasoning, planning, memory, tool orchestration, and interaction with APIs and enterprise systems.
• Understanding of evaluation, monitoring, guardrails, and observability practices for Generative AI and Agentic AI solutions in production environments.
• Strong leadership skills with the ability to guide, inspire, and grow technical teams.
• Ability to adapt to diverse contexts, teams, and client environments.
• High autonomy combined with a collaborative mindset.
• Motivation for international projects and willingness to travel when needed.
• Excellent communication skills, able to translate complex concepts for both technical and non-technical audiences.
• Proactive, ownership mindset, and committed to delivering high-impact solutions.

Nice to have:

• 2+ years of experience with SQL.
• Experience with Java, Scala, or Spark in production environments.
• Knowledge of distributed/cloud environments: AWS, Azure, GCP, Cloudera.
• Understanding of Data Governance frameworks.

What’s in it for you:

• Hybrid way of working with flexibility and balance
• Opportunity to work on international projects
• Possibility to explore different roles and career paths
• Continuous learning and development opportunities
• A growing AI‑driven environment, working with the latest technologies
• A set of benefits and perks to support your day-to-day

A place for everyone

At Celfocus, we are committed to cultivate a diverse and inclusive workplace. As an equal-opportunity employer, we welcome applicants of all backgrounds, gender identities, and abilities.

If you require any adjustments during the selection process, please inform our Talent Acquisition Team.

Celfocus is pioneering the future of business through Next-Gen Intelligence - the convergence of data, AI, and human creativity to build more autonomous and adaptive organisations.

Guided by our core belief - Making Data Actionable - we partner with leading companies to co-create intelligent solutions that turn data into insight, agility, and business value.

Operating in over 25 countries, we bring together business experts, data scientists, and AI engineers to turn complexity into clarity and vision into measurable impact.

Founded in 2000, Celfocus is part of Novabase, listed on Euronext Lisbon.

To know more, visit www.celfocus.com