Introduction

When you think of data science, your mind may go straight to dashboards, Python code, or complex models. But in the world of travel, data plays a much more human role. At Booking.com - a global leader where data meets exploration - it’s not just about numbers. It’s about shaping experiences for millions of travelers worldwide. Few people understand this better than Nadia Tomova, Lead Data Scientist at Booking.com, whose nearly decade-long journey with the company mirrors the evolution of the field itself.

In this interview, Nadia shares how she moved from politics to data science, why she sees herself more as a "decision scientist," and what travel - both personal and professional - has taught her about making better decisions with data.

From Politics to Python

Nadia didn’t start out in tech. Her background was in international politics, and she admits that, early on, she didn’t even know data science existed. When she first applied to Booking.com, she wasn’t expecting much. But after completing a challenging assignment on her own and impressing the team with her attention to detail, she landed the job.

"You can break into data science even without a technical background," Nadia emphasizes.

"What matters most is curiosity and analytical thinking."

This mindset still shapes her approach today. Her early days at Booking taught her that learning on the fly and solving problems creatively can be more important than memorizing technical concepts.

Data Science in the Travel Industry

Working in travel tech is a unique challenge. Unlike e-commerce or finance, where choices can be simple and transactional, travel is emotional and unpredictable.

"We’re designing for the entire world," she says.

"It’s massive, dynamic, and deeply human."

Over the years, Nadia has worked on everything from graduate programs to AI fairness. Currently, she focuses on non-accommodation services - flights, taxis, attractions - and is leading efforts to make experimentation faster and safer. Her team even developed tools to assess the "safety" of experiments, quantifying elements that aren’t easily captured in numbers. This innovative work has taken her to lecture halls at MIT and the University of Amsterdam.

"Sometimes the most impactful work isn’t fancy," she reflects.

"It’s about helping people make better decisions."

Experimentation is Everything

At Booking.com, experimentation is at the heart of data science. Nadia points out that while rigorous analysis is important, real-world decision-making rarely happens in perfect conditions.

"You’re constantly balancing rigor with product timelines," she says.

"Data science is really about decision-making - or as I call it, decision science."

Her experience shows that even imperfect data can lead to valuable insights if - of course - approached  thoughtfully and respectfully, with care and precision.

Advice for Aspiring Data Scientists

For students and early-career professionals, Nadia offers simple but important advice: focus on transferable skills and storytelling.

"Don’t worry about checking every box. Learn to communicate insights clearly and think critically. At university, you’re given clean datasets and clear tasks - in the real world, nothing is ever that straightforward."

She stresses the importance of soft skills, from problem solving to structuring arguments. And while she admits she doesn’t read cover letters herself, she believes they matter: "It shows you care. Just make it sound like you."

AI tools can help too. She encourages candidates to use ChatGPT to brainstorm ideas for resumes and cover letters - but always edit them to reflect their authentic voice.

The Most Data Scientist Thing She’s Done While Traveling

When asked about her most "data scientist" moment while on holiday, Nadia laughs and shares a story about helping a friend who's an influencer. One day, her friend noticed that posts shared on Facebook weren’t showing up, while Instagram worked fine. Worried she might have been banned, she turned to Nadia for help. Smiling, Nadia reassured her friend with a laugh: "Don’t worry, they’re probably running blackout experiments. These things are temporary." She explained that such experiments are common to test algorithms. Nadia confidently predicted the issue would resolve in a few days - and it did. Everything returned to normal.

"Sometimes," Nadia says with a grin, "data intuition comes in handy even when you’re just helping friends on vacation."

Why It Should Be Called Decision Science

Nadia believes the title "data scientist" doesn’t fully capture the job.

"It should be called decision science," she says.

"You often have to make choices without perfect data. That’s where experience and judgment come in. Often, it’s about seeing the bigger picture, not obsessing over flawless numbers."

Travel As a Metaphor

If her career at Booking.com were a destination, Nadia says it would be Boston.

"It’s academic but not stuck-up. It’s filled with ideas, collaboration, and people eager to learn. That’s exactly how I see my journey here."

Nadia’s story is a perfect example of how curiosity, adaptability and a deep understanding of both people and data can shape a meaningful and impactful career. From her unexpected beginnings and learning on the go, to driving global experiments and applying her knowledge even during casual conversations with friends - she proves that data science is not only about numbers, but also about asking the right questions, navigating uncertainty, and helping others make smarter decisions. Whether in the office or on Instagram, Nadia shows that the mindset of a data scientist truly never switches off.