Senior Data Scientist

About us

Founded in 2015 in Athens, Greece, Welcome redefines the way people travel by going above and beyond the commoditized transfer service and being the first company to deliver a complete, personalised, in-destination travel experience. From the moment a traveler arrives at a new destination, until their return journey home, Welcome accommodates all their travel needs, including transfers, sightseeing trips, and local information, in the easiest, friendliest, and most personalised way possible. Welcome's drivers are experts in the area and share their local know-how to make travellers feel at home wherever they are. The company has also introduced contactless rides, thorough cleaning protocols, and protective equipment to make every journey safe.

Being a travel tech startup, Welcome continues to grow and scale its operations and is quickly becoming a global category leader for in-destination travel services.

• One of the highest-rated global transportation companies with a rating of 4.9/5 stars.
• Expanded from 200 destinations last year to 350, achieving our ambitious 2024 growth target.
• Over 4,000 travel partners including 2,500 hotels, numerous vacation rentals, and travel agents, adding 50+ new ones every month.
• Over 2.5 million happy travellers every year.

⭐️ If you want to dive deeper into the awesomeness of Welcome's culture, click on  to check our TikTok account.⭐️

The Team

We are a group of vibrant, diverse people who love travelling and never settle on quality. Each one of us didn’t join Welcome by chance and believes deeply in what Welcome is trying to achieve, so we work relentlessly to make that happen. We challenge common logic, focus on design, put simplicity and usability first, and create memorable experiences. We keep learning and exploring better ways to serve our community and grow personally and professionally in our respective fields. We stay humble along the way, with a “pay it forward” mentality, but with big and bold goals.

As a Senior Data Scientist, you will be leading the evolution of forecasting and model-driven decision-making across our Operations teams. In this role, you will transform how we predict demand, supply, and transfer performance by replacing manual business rules with intelligent models and scalable data products. You’ll build models that predict demand, driver availability, and operational performance - ensuring the right driver supply at the right time, across 90+ destinations. 

Your work will directly shape recruitment planning, incentive design, and marketplace balance during peaks and surges. You’ll work hands-on with GCP, dbt, and BigQuery, and you’ll collaborate closely mainly with operations stakeholders to ensure your models deliver measurable business impact.

This is an opportunity to shape the company’s data science foundations - designing models that don’t just explain what happened, but anticipate what comes next.

Responsibilities

• Lead forecasting initiatives for key operational metrics such as transfer volume, capacity utilization, and driver allocation.
• Develop forecasting models at multiple granularities - by destination, car type, seasonality, and event impact - to guide both strategic and short-term operational decisions.
• Build scenario simulation frameworks to test the impact of recruitment, pricing, or incentive changes on supply - demand balance.
• Monitor model performance against realized outcomes, quantify forecast error, and continuously retrain models based on new data and feedback.
• Establish model monitoring, versioning, and drift detection practices to ensure sustained performance and reliability.
• Conduct feature engineering and sensitivity analysis to improve model interpretability and business trust.
• Build, test, and deploy models in an environment built on GCP (BigQuery, Vertex AI) and dbt.
• Collaborate with analytics engineers and data analysts to ensure clean data modeling and seamless integration between analytical and predictive layers.
• Partner with Operations teams to frame problems, define KPIs, and translate models into actionable recommendations.
• Communicate results clearly to both technical and non-technical audiences, linking model outcomes to operational decisions.
• Mentor analysts or jr. data scientists and contribute to the development of a modern data science culture.

• 6+ years of experience as a Data Scientist, with a proven record in forecasting, predictive modeling, and operational analytics.
• Strong proficiency in Python (pandas, scikit-learn, XGBoost, Prophet, statsmodels) and SQL.
• Hands-on experience with GCP (BigQuery, Vertex AI, Cloud Storage) and dbt for data transformation and modeling.
• Strong understanding of time-series modeling, demand forecasting, and model evaluation (MAPE, RMSE, etc.).
• Collaborate closely with Destination Success, Driver Supply, and Pricing teams to translate forecasts into recruitment plans, incentive programs, and market interventions.
• Experience collaborating with cross-functional teams (Operations, Product, Commercial, Finance) to identify and scope high-impact use cases.
• Familiarity with MLOps principles: version control, deployment, and monitoring - even at a lightweight scale.
• Excellent communication and presentation skills; able to distill complexity into clear business insight.

Nice to Have

• Experience with causal inference, scenario simulation, or optimization models.
• Background in mobility, travel, logistics, or marketplace operations.
• Knowledge of model governance and documentation frameworks (data lineage, explainability, ethics).
• Familiarity with forecasting libraries such as Prophet, Orbit, or sklearn-compatible custom time-series modules.

Our Tech Stack

• Data warehousing & transformation: Google Cloud BigQuery
• Data visualization & reporting: Power BI, Microsoft Power Suite
• Project & workflow management: Atlassian Suite

• Vibrant and fresh work environment
• Flexible work-from-home policy
• The tools you need to perform your daily tasks successfully
• L&D personal budget
• Private Insurance Plan
• +4 extra PTO days annually
• The unique opportunity to join “the next big thing” at ground level