Data Science Intern

Cozycozy is the only platform that gives you real-time access to every type of holiday accommodation in one search. Hotels, apartments, Airbnbs, hostels, villas — even treehouses: we aggregate 20M+ listings from 100+ booking sites (Airbnb, Booking.com, Abritel/VRBO, hotels.com, and dozens of specialised marketplaces) across 50+ countries and 20 languages, with offices in Paris and Budapest.

Founded by the team behind Liligo and backed by Daphni, Xavier Niel and Thibaud Elzière, we already handle millions of searches monthly and we're growing fast 🚀

Our mission: Be the single place travelers need to compare every accommodation option, transparently and in real time, with results suited to their personal preferences.

Our ambition: Build the world's best accommodation metasearch and scale it into every market.

About the role

We’re looking for a Data Science Intern for a 6-month internship, starting now or in January 2027, to sit at the heart of how cozycozy makes decisions. You won't be a spectator: you'll turn raw product and partner data into operational intelligence for our Revenue, Marketing, Product and Finance teams, harden the data foundations we all rely on, and build AI-driven workflows from the ground up. On top of that, you'll own a real machine-learning project shipped to production.
You'll work closely with the founders in a small, high-impact team where every deliverable is used by real people and moves real numbers.

What you’ll do

1. Data reliability and foundations: Partner with Data Engineering to run sanity and reliability checks to improve decision-making at the company.

2. Operational data intelligence: Product and partner data analysis to support the Finance, Revenue, Marketing, and Product teams. You could for instance study the booking funnel, design and run hypothesis testing for a major product release or run the ad hoc analysis that answers the questions leadership is obsessed about.

3. AI-driven data workflows: Design and orchestrate AI-powered data workflows that support core company processes: partner data collection, data harmonization, and self-serve tooling for internal stakeholders.

4. ML project: A production-grade machine-learning project, scoped to the natural fit with your profile. One of:

   • Ranking: study the performance of our existing ranking algorithm, identify improvements, and A/B test them in production against the current system; or
   • Marketing allocation: study how marketing spend is currently allocated (historical trends and their performance) and design a framework to dynamically allocate and adjust investment across channels and markets

What we’re looking for

• You’re a strong fit if you are currently completing a Master’s or engineering degree at a Grande École or equivalent top program

• Organized and rigorous: structured and precise, you back every decision with data and don’t approximate.

• Entrepreneurial: curious, comfortable with ambiguity and willing to step outside your comfort zone.

• Eager to experiment and learn with Generative AI: you want to challenge how things are done and build from the ground up, even if that means redesigning the process itself.

• Core skills we’re looking for :

  • Python for data analysis, visualization (pandas, seaborn) and machine learning.
  • SQL to pull and transform data.
  • Git workflow to version your work and collaborate with your team.

• Nice to have :

  • Familiarity with recommender systems and ranking algorithms, or with marketing analytics (MMM).
  • Hands-on hypothesis testing in a real-world setting and experience with a BI tool (e.g. Metabase).

• You are fluent in English (written & spoken). French is a plus.

Why join Cozycozy?

🚀 You’ll operate in a key role in the development of a fast-growing travel-tech startup.

🌍 We have a diverse team spread across both Paris & Budapest, united by curiosity and collaboration.

🤖 A front-row seat to build with the latest AI, not just talk about it.

💡 We encourage initiative, creativity, and ownership. You’ll have the freedom to shape processes and lead projects end-to-end.

💶 Competitive salary, stock options, Alan health insurance, and Swile card.

Our hiring process

• Intro call with the Hiring Manager
• Technical case, presented to the Hiring Manager, the Senior Data Engineer, and key stakeholders.
• Meet the team !

What’s next?

Once we receive your application, we’ll review your CV and cover letter carefully and get back to you as soon as possible. In the meantime, get to know us by visiting www.cozycozy.com and follow us onLinkedIn ,Instagram,TikTok andFacebook !