Data Scientist -GenAI / Chatbot

1UPPLY; Utrecht; Hybrid; EUR 60,000 - 90,000; Full time

Job summary

1UPPLY in Utrecht is seeking a Data Scientist (Medior–Senior) focused on GenAI and chatbot improvements. You’ll work with data, engineering and product to analyze chatbot behavior and implement meaningful enhancements.

You will explore retrieval, generation and reasoning loops, tool calling and related GenAI capabilities, design evaluation frameworks and translate needs into concrete technical changes. The role is hybrid, with Thursdays in the office at Winthontlaan, Utrecht.

Qualifications

• Strong analytical mindset and passion for understanding AI system behaviour.
• Strong understanding of GenAI systems and experience with LLM-based applications.
• Experience with retrieval-augmented systems.
• Understanding of prompts, context windows, retrieval and grounding.
• Ability to evaluate output quality and explain effectiveness.
• Familiarity with API integrations, batch synchronisation, and structured and unstructured data.
• Ability to collaborate with engineers and troubleshoot data flows.
• Ability to design evaluation frameworks beyond traditional ML metrics.
• Understanding of functional context and user behaviour.
• Clear communication with engineers, product managers and stakeholders.

Responsibilities

• Analyse chatbot outputs and identify improvements with the greatest impact.
• Diagnose context gaps and determine what additional information agents need.
• Work with product managers and engineers to define criteria for evaluating agent performance.
• Partner with use-case teams and stakeholders to understand real-world scenarios and turn feedback into improvements.
• Improve retrieval mechanisms, data structuring and the onboarding of contextual sources.
• Design evaluation frameworks that support rapid, large-scale experimentation and continuous innovation.
• Translate functional requirements into actionable technical improvements.

Skills

GenAI systems

LLM-based apps

Retrieval-augmented systems

Prompts and context

Evaluation frameworks

API integrations

Data structuring

Cross-functional collaboration

Problem solving

Job description

Data Scientist GenAI / Chatbot

Location: Utrecht

Level: Medior–Senior

Working arrangement: Hybrid, with Thursdays in the office at Winthontlaan, Utrecht.

About the role

As a Data Scientist (GenAI / Chatbot), you’ll help improve the quality and effectiveness of chatbot systems. You’ll work across data, engineering and product, investigating how chatbots behave, identifying weaknesses and turning your findings into meaningful improvements.

Your focus is on understanding why a chatbot isn’t behaving as expected and what context or structure it needs. You’ll assess current solutions against state-of-the-art approaches and contribute to innovation in retrieval, generation, reasoning loops, tool calling and related GenAI capabilities.

What you’ll do

• Analyse chatbot outputs and identify improvements with the greatest impact.
• Diagnose context gaps and determine what additional information agents need.
• Work with product managers and engineers to define criteria for evaluating agent performance.
• Partner with use-case teams and stakeholders to understand real-world scenarios and turn feedback into improvements.
• Improve retrieval mechanisms, data structuring and the onboarding of contextual sources.
• Design evaluation frameworks that support rapid, large-scale experimentation and continuous innovation.
• Translate functional requirements into actionable technical improvements.

What you bring

• A strong analytical mindset and a passion for understanding AI system behaviour.
• A strong understanding of GenAI systems and experience with LLM-based applications.
• Experience with retrieval-augmented systems.
• A strong understanding of prompts, context windows, retrieval and grounding.
• The ability to evaluate output quality and explain why results are effective or ineffective.
• Familiarity with API integrations, batch synchronisation, and structured and unstructured data.
• Comfort collaborating closely with engineers and troubleshooting data flows and context ingestion.
• The ability to design evaluation frameworks beyond traditional machine learning metrics.
• An understanding of functional context and user behaviour, and the ability to work across engineering and product.
• Clear communication skills: you can explain context gaps and reasoning to engineers, product managers and stakeholders, and create effective improvement proposals.

Nice to have

• A background in human-in-the-loop evaluation.

Who will thrive in this role

You enjoy figuring out why AI systems behave the way they do and how they can be improved. You like debugging behaviour as well as code, think structurally, connect the dots and have a strong intuition for what good performance looks like.

Eisen

• The candidate must be able to work in English
• Midlance constructions are not allowed
• The candidate must be available throughout the entire duration of the assignment
• The candidate must work in the office on Thursdays at Winthontlaan, Utrecht, until further notice
• The candidate must be submitted exclusively to Magnit – Rabobank during the four-business-day exclusivity period for one request
• The candidate must possess a valid passport or ID card and bring it to the interview and at the start of the assignment
• The candidate may start only after successfully completing the pre-employment screening

Gunningscriteria

• Background in human-in-the-loop evaluation is a plus