Where business
and data meet.

I am Daniela Ionescu. For over ten years I have translated complex information needs into reliable, scalable BI solutions, from requirements and data models to dashboards people genuinely use. Available on a freelance basis through The Data Mama.

— About

As a Senior BI Specialist I connect business and data. Complex information needs become concrete KPIs and business rules, with clear definitions agreed up front — and then the models, marts and dashboards that make them dependable.

I combine deep expertise in Power BI, DAX, SQL, Snowflake and dimensional data modelling with strong stakeholder management. I guide solutions from intake through to production, and make sure insights are not only technically correct but also fit the way the organisation actually works and decides.

My work has spanned public transport, financial supervision and international distribution — Nederlandse Spoorwegen, De Nederlandsche Bank and Waldom Electronics EMEA — usually replacing manual Excel reporting with something maintainable, documented and governed.

— Skills

BI & Reporting

Power BI, advanced DAX, Power Query, Tabular Editor, RLS, drill-throughs, SAS Visual Analytics

Data engineering

SQL, Snowflake, SQL Server, SSIS, SSAS, Azure Synapse, SAS Data Integration Studio, Python

Data modelling

Dimensional and semantic models, data marts,  business-rule definition, data governance

Data-driven decision-making

Decision support, KPI frameworks, self-service enablement, data storytelling

— Experience

Ten years across public transport, financial supervision and international distribution. Happy to walk through any assignment in detail on a call. 


June 2024 - June 2026 ·  2 years

Nederlandse Spoorwegen (NS)

Senior Business Intelligence Specialist

Power BI · SQL · DAX · Snowflake · Power Query · Tabular Editor · Git · Azure DevOps · CI/CD · Agile 


April 2018 - July 2024  ·  6 years

De Nederlandsche Bank (DNB)

BI Specialist / Data Engineer

Power BI · SQL · DAX · SAS Data Integration Studio · SAS Visual Analytics · Azure Synapse · Power Query · Agile


April 2016 - March 2018  ·  2 years

Waldom Electronics EMEA

Global Data Analyst

Power BI · SQL Server · SSIS · SSAS · DAX · Power Query


Four Power BI dashboards delivered independently within two years, each from intake to production: Leren, CSG Schoon Audits, KBM and OV-fiets — helping contain re-examination costs and steer cleaning quality, passenger satisfaction and bike availability more precisely.

Translated complex information needs into concrete KPIs and business rules, with definitions and agreements settled up front.

Designed dimensional and semantic models; analysed and combined internal and external data with SQL in Snowflake into one dependable reporting foundation.

Built usable dashboards with advanced DAX, row-level security, drill-throughs and tooltips, and facilitated workshops with HR, facilities, marketing and operations.


Six years supporting Supervision and Resolution: ETL processes, data marts and reusable Power BI and SAS Visual Analytics dashboards that replaced manual Excel reporting, including the redesigned supervision approach - ATM.

Integrated a range of data sources and developed self-service BI data marts with SAS and Azure Synapse.

Contributed to the migration of SAS solutions to Microsoft Azure and analysed the consequences for existing data flows.

Chaired the ETL and BI community, coaching colleagues on tooling, knowledge sharing and best practice.


Data models designed and built with SQL Server, SSIS and SSAS for the Sales and Pricing teams, turning unstructured ERP and Excel data into a structured BI environment. 

Developed and improved Power BI dashboards for supplier, sales, operational and management reporting. 

— Certificates

Power BI Data Analyst Associate (PL-300)

SAS Macro Language 1: Essentials      

Data Engineering on Microsoft Azure (DP-203) 

Course - Global Knowledge 

Data Fundamentals on Microsoft Azure (DP-900)

Course - Global Knowledge

Scrum Developer

Course - Scrum.org

Data Science and Machine Learning with Python

Course - Ilionx

— What do clients say

Janneke Dings (IT Manager @ DNB)

Daniela worked as a Senior Data Engineer in one of the data teams under my responsibility. We worked together for over three years, to my complete satisfaction. Daniela delivers results, has extensive knowledge across various ETL and data domains, and continuously develops her expertise through professional training. She is sociable and works extremely well with others. Both her direct colleagues and internal business stakeholders greatly value her qualities and actively seek to involve her in their work.

Erik Kerkmeijer (Data Engineer @ NS)

Daniela is a highly professional and pleasant colleague. I really valued discussing and exchanging ideas with her about data-related topics, including both new developments and production issues. She is highly skilled in developing Power BI dashboards and also has strong SQL capabilities. She is a true team player who takes initiative. In short, she would be a great asset to any organization!

Claudia Kerkhoff (Data Analyst @ DNB)

We worked together for over six years as part of a BI team at DNB, and I truly enjoyed our collaboration.

Besides being a sociable, cheerful, and caring colleague, you are also highly skilled and proactive. Whether it involves data integration, building data models, or developing dashboards, you take it all on. You are customer-focused and always willing to help.

Wishing you every success in your next steps, Daniela!

Diego Tjon Eng Soe ( BI Specialist @ NS)

I found working with Daniela in her role as a BI Specialist to be a very positive experience. She worked purposefully and was able to quickly translate complex data challenges into practical insights that delivered immediate value to the organization.

Daniela combines a professional and analytical approach with a hands-on mentality. Even in complex or dynamic environments, she brings structure and remains focused on achieving tangible results and creating business value.

She also possesses strong communication skills. She interacts with stakeholders naturally and professionally, enabling her to effectively bridge the gap between business and technology. She guides colleagues through changes in an accessible way and is always ready to support users.

What also stood out to me was her drive and strong sense of responsibility. She has a keen eye for data quality and can deliver both robust BI solutions and pragmatic short-term solutions tailored to the organization's needs. Daniela is proactive, results-oriented, and a pleasure to work with.

— Peter Baken (Data Analyst @ DNB)

As an analyst, I worked with Daniela for over three years while she was a BI Developer in an Agile team. Daniela has extensive hands-on expertise, is creative in finding solutions, takes initiative, and is a highly sociable person. Her great sense of humour also makes her a pleasure to work with.

Let's discuss your data

A Power BI landscape that needs building or rescuing, a data model to design, reporting your teams don't yet trust, or a BI function that needs experienced hands for a few months. Outline the situation and I will reply within two working days. 

Or just give me a call.

Curious how I think about data? Read my latest articles on LinkedIn.