Senior Data Analyst

Senior Data Analyst - SQL Specialist in OnePortal (e-commerce)

• Lead deep-dive analyses to uncover business trends, user behavior, and operational inefficiencies
• Translate data into clear narratives and visual stories for product, business, and technical stakeholders
• Define and maintain KPIs for specific product domains or journey
• Build and maintain dashboards and automated reports to monitor performance and identify trends
• Serve as the go-to analytics contact for business, product, and operations teams
• Turn open-ended business questions into testable hypotheses and structured problem-solving approaches
• Support A/B testing from design to interpretation
• Ensure accuracy, consistency, and trustworthiness across all reporting layers
• Audit data logic and pipelines, and flag anomalies and inconsistencies
• Partner with engineering teams to maintain data integrity
• Deliver timely and actionable insights to support strategic initiatives, product launches, campaign performance, and continuous optimization
• Prioritize findings by business impact and urgency
• Work closely with Data Engineers, PMs, and other Analysts to maintain consistency across metrics and improve decision-making
• Influence product and analytics roadmaps through recurring insight-driven recommendations

• Proficient in SQL, with experience querying large datasets and optimizing performance
• Skilled in data visualization tools (e.g., Tableau, Power BI, Metabase)
• Experience in Python or R for analysis and automation is a plus
• Strong understanding of product funnels, user journeys, and cohort analysis
• Familiarity with A/B testing methods and statistical evaluation
• Solid business acumen — you know how to turn numbers into actionable decisions
• Clear and confident communicator — able to present findings to both technical and non-technical audiences
• Detail-oriented with a commitment to data quality and governance
• Comfortable juggling multiple tasks in a fast-paced, agile environment

Join One Portal and Lead Data-Driven Decisions at Scale

One Portal is a pan-European B2B eCommerce and self-care platform transforming how business customers interact with Deutsche Telekom across multiple markets. Behind the platform stands data — complex, cross-country, and rich with opportunities to drive real business impact.

We are looking for senior data professionals who want more than dashboards. In this role, you will shape how data is used across the product and markets: from defining metrics and analytical frameworks, through advanced analysis and experimentation, to influencing strategic product and business decisions.

As a Senior Data Analyst you will work at the intersection of product, technology, and business. You will collaborate with product owners, engineers, UX, and local market teams, helping them move from intuition to evidence-based decisions. Your insights will directly influence roadmap priorities, adoption strategy, customer experience, and platform scalability across Europe.

This is a role for someone who enjoys ownership and leadership — setting standards, mentoring others, and building a strong data culture in an international, agile environment. You will deal with large-scale, multi-market data, complex user journeys, and real-life business problems, not theoretical exercises.

If you are passionate about turning data into action, influencing decisions at scale, and building data maturity in a growing international product — One Portal is the place where your impact will be visible and meaningful.

Apply and help us build a truly data-driven B2B platform across Europe.

In our recruitment process, you can expect honesty and transparency. We consider each candidacy carefully and fairly, without any exceptions. We don't look at your race, skin color, sexual orientation, gender identity, nationality, disability status, beliefs, appearance or religion. It's your competencies that count.

We also guarantee that you will always receive feedback when participating in recruitment for #MagentaTeam.

We are a technology company, and our goal is to create innovative solutions for individual and business clients.

At T-Mobile, we all live in a magenta world This color is close to our hearts and means faith in the success of undertaken actions, self-confidence, and endurance.

That's who we are as a team.

At #MagentaTeam , we focus on exchanging experiences, agile work, and quick adaptation to changes #MagentaTeam is, above all, a mix of different competencies, experiences, personalities, temperaments, and views. And this diversity is our greatest strength.