Marketing Data Scientist

Role summary

Marketing Data Scientist is a full-time role at Hostelworld Group in Porto, Portugal (hybrid). Posted 2026-08-25. Experience level: 2-5.

Job title

Marketing Data Scientist

Company

Hostelworld Group

Location

Porto, Portugal

Work arrangement

hybrid

Employment type

full-time

Category

Data Science

Experience level

2-5

Date posted

2026-08-25

Job description

ABOUT US 🚀

Hostelworld is the world's leading Social Travel platform - a social network-powered OTA on a mission to help travellers find their people and create unforgettable moments together. Founded in 1999 and headquartered in Ireland, we're a team of around 270 people serving hostel partners across more than 180 countries.

Since launching our social network in 2022, we've welcomed over 3.4 million social members who aren't just booking trips, they're messaging, finding events, meeting up and becoming powerful brand advocates. This community generates a rich proprietary dataset of 16 million+ chat messages and 17 million bookings, powering AI-driven personalisation and network effects that no generalist OTA can replicate.

We are not just another OTA - we created an entirely new category – Social Travel. If you want to shape the future of travel by putting people and shared experiences at the heart of it, you'll fit right in here - Learn more about our Team!

Our Culture

At Hostelworld, our culture is a direct reflection of our customers: adventurous, curious, and social. We have a shared love of travel that fuels our work and connects us on a deeper level. It’s a fast-paced environment that blends the agility and "scrappy" resourcefulness of a start-up with the experience and ambition of a global, publicly listed company.

We are a team of pragmatic optimists who are data-obsessed and results-driven. We value a ‘test and learn’ mindset, encouraging experimentation and empowering our teams to take calculated risks. We believe in doing the right thing—for our customers, our partners, and each other. We foster a supportive and collaborative atmosphere where diverse perspectives are celebrated, and where every team member has the opportunity to make a significant impact on our journey. We embrace the journey, not just the destination, and we seek leaders who will thrive in a dynamic environment and inspire their teams to do the same.

LOCATION🌍

This role is based in Portugal. We have an office hub in Porto available for those who prefer a hybrid model where you can spend time with colleagues in-person. You will need to be able to commute to our office hub as required from time to time.

WHO YOU'LL WORK WITH 👨🏽‍🤝‍👨🏼

You will play a key role in a diverse, highly-talented Analytics & Insights team providing insights across a number of growth units including paid marketing, customer analytics and app analytics to support decision making at C and senior management level. The Marketing Data Scientist will play a pivotal role in driving data-informed marketing strategies and decisions, with a particular emphasis on managing and optimising Google Ads bidding algorithms. As a key member of the Analytics and Insights team, this role will involve close collaboration with paid marketing, app marketing, and data teams to uncover insights, optimise campaigns, and contribute to business growth.

WHAT YOU'LL DO 👩‍💻

You will hone and develop a wide range of technical skills in managing our data analytics and data science products. The paid analytics team require a person who is flexible, adaptable and able to translate business needs into measurable results. It’s a rewarding experience with exciting diverse work:

Bidding & spend optimisation

Develop, manage and optimise bidding algorithms for Google Ads campaigns (Search and Hotel Price Ads) using Python, translating business objectives into bidding logic that maximises profitability (Direct Margin).

Optimise budget allocation across channels, markets and campaigns using elasticity and response-curve models to improve profitability.

Continuously monitor campaign performance, identify inefficiencies and evolve the bidding logic accordingly.

Marketing measurement & incrementality

Design, run and analyse incrementality tests (geo-lift / holdout experiments) using causal inference methods such as synthetic control, Bayesian structural time series and difference-in-differences to quantify the true incremental impact of paid channels.

Build and maintain marketing mix models (MMM) to estimate channel contribution, saturation and diminishing returns, and translate the outputs into budget recommendations.

Own and improve our attribution framework — evaluating multi-touch attribution against experimental results and platform-reported figures, and reconciling the gaps.

Design, implement and analyse A/B tests and other experiments to assess the impact of marketing initiatives, including sample-size, power and pre-registration standards.

Insight & influence

Provide data-driven recommendations on marketing spend, customer acquisition, retention and lifetime value to C-level and senior management.

Serve as a subject-matter expert on data science and measurement best practices within the Analytics & Insights team, and productionise analyses into reusable tools and recurring reports.

WHAT WE’RE LOOKING FOR 👀

Experience & Qualifications:

Minimum 3 years of experience in a Data Analytics or Data Science role, preferably within a marketing department.

Advanced skills in SQL, Python, R, or similar programming languages.

Excellent problem-solving skills and attention to detail.

Communicate clearly and with purpose, working effectively with team members and stakeholders across the organisation.

Ability to work independently and as part of a team in a fast-paced environment.

Essential Skills:

Competency in Python/R.

SQL (preferably BigQuery, Snowflake).

Strong proficiency in statistical analysis, machine learning, and predictive modelling techniques.

Desirable Skills:

Experience with marketing measurement: incrementality / geo-lift testing, holdout experiments.

Applied causal inference: synthetic control, difference