Marketing Data Scientist

Marketing Data Scientist Apply Now! 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-in-differences, Bayesian structural time series (e.g. CausalPy, CausalImpact, PyMC, linearmodels). Understanding of attribution modelling (multi-touch, data-driven attribution) and its limitations relative to experimental measurement. Understanding of digital marketing metrics, SEO, SEM and customer-journey analysis. Experience with data visualisation tools (Tableau, Looker, Power BI) or building lightweight apps (Streamlit). Familiarity with orchestration and ETL/ELT tools (Apache Airflow, dbt). Experience with version control (Git) and collaborative code review. WHAT WE OFFER 💯 Competitive salary & benefits Enhanced annual leave plus 3 Wellbeing Days per year Paid family leave (maternity, paternity, surrogacy & adoption) Agile working (plus a Working from Abroad Policy!) Support for your ongoing growth & development Inclusive people policies (sickness, menopause, compassionate and fertility leave) A chance to give back to your local community with 5 paid volunteering days OUR BEHAVIOURS 🏆 Grow others - We fundamentally believe that investing in growing others benefits everyone, whether it's helping them develop hard or soft skills. We want learning and growing to be part of our DNA to help makes us a better team, together. Master it - We are obsessed with our area of expertise and enjoy developing our skills. We rarely take things at face value; we investigate, interrogate, and always look for ‘the why,’ and wherever possible, we use data to find the best solution. Collaborate - We are in it together, for the tough stuff and the celebrations too. To achieve the best results, we need expertise from all areas of the organisation, and we wholeheartedly welcome diverse thinking. Adapt - We work fluidly, adapting to new information and the evolving environment while staying committed to our goals. Innovation and experimentation fuel our projects and we’re never afraid to pivot. Deliver - Our focus is always on the end result; we value outcomes over activity. We collaborate to deliver work at speed without dropping any of our other behaviours. We believe in talented and diverse teams that reflect the diversity of our customers and the communities in which we operate. Everyone brings different perspectives and experiences. We lay out the above requirements to guide applicants to the experiences that we believe will allow you to be successful in the role. If you don’t meet them all, please consider applying if you think you can still perform the role as described. Department Marketing Locations Porto Remote status Hybrid About Hostelworld Group Hostelworld Group plc is a ground-breaking social network-powered Online Travel Agent ("OTA") with a clear mission to help travellers find people to hang out with. Our mission is founded on the insight that most travellers go hostelling to meet other people. Our platform connects travellers through a range of social features, including city and hostel chat rooms, AI-powered recommendations, and event discovery, facilitating real-world interactions before, during and after their trips. Hostelworld's vision is to be the world's leading social travel platform. Since launching its social network in 2022, the Group has welcomed over 4.0 million social members, with engagement growing faster than stays booked. Social members book approximately twice as frequently as non-members and are three times more likely to use the app, demonstrating the platform's utility and its contribution to customer lifetime value. Our proprietary dataset, spanning over 4.0 million social members, 19.0 million chat messages and 19.0 million bookings since launch, strengthens our ability to understand traveller behaviour, personalise experiences, and build network effects that differentiate Hostelworld from generalist OTAs. This data asset, which is exclusively ours and compounds in value as our community grows, underpins our AI-powered matching and recommendation capabilities. Founded in 1999 and headquartered in Ireland, Hostelworld is a recognised brand with around 275 employees, hostel and accommodation partners across more than 180 countries, and a growing suite of products including budget accommodation and Social Passes that extend the platform well beyond the traditional hostelling category. Hostelworld has a long-standing commitment to improving the sustainability of the hostelling industry. The Group has introduced a hostel-specific Staircase to Sustainability framework, accredited by the Global Sustainable Tourism Council, which helps partners adopt more sustainable practices while giving travellers clearer information for decision-making. Customers can choose to offset trip emissions, and for the fifth consecutive year the Group has retained the 'Taking Climate Action' label from South Pole. To read more, please click here ! Founded in 1999 Co-workers 275 Turnover €93.8m (2025)