Kalin Stefanov

Sr Data Engineer / Architect

Geneva, Switzerland

Experience

Dec 2024 - Present
7 months

Sr Data Engineer / Architect

Samsung Logistics

  • Architected and implemented a structured three-layer enterprise datawarehouse model in Azure, establishing a robust and scalable data environment.

  • Migrated legacy stored procedures to streamlined Azure Data Factory (ADF) pipelines, enhancing data processing efficiency.

  • Introduced comprehensive Git-based source control, ensuring rigorous version management and collaborative development practices.

  • Established automated data quality frameworks with proactive monitoring and alerting, significantly improving data integrity and reliability.

  • Spearheaded the design of an enterprise data model, enabling a self-service BI environment that empowered business teams with advanced analytics capabilities.

  • Developed and delivered insightful dashboards and reports in Power BI, transforming raw data into actionable business insights.

  • Azure Data Factory (ADF), Azure, MS-SQL, DataVault 2.0, Git, Power BI, Data Quality Automation, Agile/SCRUM, Data Modeling, Self-service BI, Stakeholder management.

Mar 2024 - Dec 2025
10 months

Sr Data Engineer / Manager

Booking.com

  • Played a key role in designing and building data marts (models) and pipelines for structured data in the Datalake, with a focus on SCM (suppliers) and marketing projects.

  • Led a migration team (4 FTE) to convert the existing ETL pipelines to a Snowflake environment, including data modeling.

  • Developed complex data pipelines in PySpark, Python, Airflow, and HQL (Hadoop Hive SQL) for large-scale data processing, with strong technical and architectural expertise.

  • Worked in an Agile Scrum team with over 30 multidisciplinary team members, ranging from business analysts to data scientists.

  • Airflow, DBT, SQL, Python, Spark, Snowflake, Grafana, Visual Studio Code, Hadoop, Perl, Bash UNIX scripting, Stakeholder management.

Feb 2023 - Dec 2023
11 months

Sr Data Engineer / Architect

ANWB LLC

  • Played a dual role as Data Engineer and Solution Architect, leading the reengineering of data marts within the Road Assistance department to align with the strategic migration to the Snowflake environment.

  • Directed the reverse-engineering of the Customer Demand List (CDL) to optimize performance, exhibiting a strong blend of technical proficiency and architectural oversight.

  • Departed post-implementation phase due to budgetary constraints, after ensuring a robust foundation for the department’s data operations.

  • Snowflake SQL, Azure, MS-SQL, SSIS ETL, Upsolver, JIRA, Agile/Scrum, DevOps, DataVault 2.0, QlikView, PowerBI, DataHub, DataVault, ANWB Hulpverlening, Data Quality Automation, Data Science, Hackathons, AI/ChatGPT.

May 2019 - Jan 2024
4 years 9 months

Sr Data Engineer

DaisTech LLC

Worked for 4.5 years for several US companies as self-employed. Gained solid knowledge and experience of cloud server technologies, Python programming language, data orchestration tools, and big data.

  • Meta Platforms Inc. (Facebook) | Menlo Park, US**

  • Designed and developed multiple data marts and dashboards for the Infra department in cooperation with Data Scientists.

  • Proactively identified usable data points to facilitate mitigation responsive times for Oncall teams.

  • As an end-responsible tech lead: proposed, designed, and developed end-to-end solutions including data analysis, data transformation logics, data pipelines, visualization, system test, UAT, and presentations to partners.

  • Presto SQL, Unidash, Python, Big Data, Data lake, Hive, Oncall teams, Infra.

  • Boston Consulting Group | Boston, US**

  • Reverse-engineered (Oracle DI, SQL Server) pipelines to Snowflake SQL.

  • Re-implemented as data mart views in Snowflake and automated pipeline orchestration and feed solutions using Fivetran.

  • Fulfilled the roles of tech lead and liaison between business units and tech support during migration projects.

  • Snowflake SQL, Fivetran, MS-SQL Server, MySQL, Gitlab, PL/SQL, Oracle, SAP Enterprise, Slack, Jira.

  • Randstad Technologies | Atlanta, US**

  • Designed and created dimensional enterprise data models, migrated data, and developed new data pipelines and marts, performing quality assurance testing, code reviews, and releases for billing, staff placements, and customer domains in Agile/SCRUM teams.

  • Reverse-engineered Talend ETL pipelines, shifting them to an ELT tech stack based on an Apache Airflow-driven system running on Google Cloud Platform (GCP) BigQuery.

  • Enhanced custom code generation systems to handle configurations.

  • BigQuery, Python, Airflow, Datamarts, Spinnaker, Gitlab, Talend, Oracle, SQL, SOA.

  • WarnerMedia (HBO) | New York, US**

  • Enabled marketing analytics by loading advertising data into Snowflake using pipelines built with Apache Airflow, Python, and SnowSQL.

  • Created a Python-based solution for automated data quality verification and alerting.

  • Re-engineered an existing Data Warehouse to be unified for increased efficiency and eliminated redundancy.

  • Mentored remotely based team members to reduce onboarding time.

  • Snowflake, Python, Github, JSON, Airflow, Data modelling, Agile/SCRUM, Team-lead.

  • Newsela Inc. | New York, US**

  • Migrated user activity tracking and engagement warehouse from Redshift to Snowflake using Loome streams.

  • Optimized SnowSQL scripts for 40% cost reduction.

  • Designed and integrated automated schemes to validate data anomalies and calendar exceptions.

  • Snowflake SQL, SOA, Python, Looker, Loome, Fivetran, Kinesis, Amazon (AWS), Redshift, JSON, Enterprise Data Integration, Data lake - marts - models.

Jul 2011 - May 2019
7 years 11 months

Data Engineer & BI/DWH Consultant

Dais

Worked for eight years on contracting basis for numerous organizations in The Netherlands and delivered high-quality services to improve clients’ data structures, information systems, and business management.

  • Volkswagen Pon Financial Services | Amersfoort, NL**

  • Designed and developed a custom sensitive data anonymization tool.

  • GDPR, MS-SQL, SSIS, C#, VB.NET.

  • NIBC NV | The Hague, NL**

  • Participated in over seven enterprise data projects in various roles as Sr MSBI developer, data analyst, and DWH modeler.

  • Regulation Reporting: Anacredit, DGS, VIA, Cost Allocation Model, Data Virtualization.

  • ING Bank | Amsterdam, NL**

  • Redesign and rework of a mis-performing reporting system, acting as a Scrum Master and technical SQL lead.

  • IFRS9, Liquidity Coverage Ratio (LCR), Oracle PL/SQL, SAP, DNB, ECB, MiFID II, FINREP, COREP.

  • WSW | Hilversum, NL**

  • Developed software solutions for financial & business risk models of Real Estate organizations.

  • S&P matrix, T-SQL, SSIS framework, DQM, MDM, QlikView.

  • KASBANK | Amsterdam, NL**

  • Implemented data warehouse solutions as Sr. BI Developer.

  • Agile/SCRUM, Lead BI, MS-SQL, Kimball, BI framework, SSIS ETL, C#, ISIN, Custodian.

  • Simon Loos | Wognum, NL**

  • Database migration for logistics planning systems.

  • MS-SQL, Kimball, Cost-Effective Planning, Transport, Logistics, SSRS, Agile/SCRUM.

Sep 2008 - Aug 2011
3 years

Data Engineer & BI/DWH Consultant

Ordina

VisionWorks team contributing as a data consultant for high-paced marketing, gaming, and finance solutions.

  • Rabobank Corp. Utrecht (NL)** Marketing software back-end integration in CRM.
  • Keywords: Marketing Campaign Management, SAP CRM HPNeoView Banks Clients.

Summary

Senior technical engineer with 15+ years of experience helping companies to structure and leverage business data and information management systems to drive decision-making.

Key strengths in business process consulting, data modeling and integration as well as data flow automation.

Always taking ownership and shows leadership. Good in project management, stakeholder management and multi-disciplinary global teamwork.

Recently moved from New York to Geneva. Looking for suitable position on contracting or perm basis.

Languages

Dutch
Native
English
Advanced

Education

Feb 2016 - Apr 2019

Open Universiteit

Master of Science, minor: Data Science & Analytics · Business Process Management & IT · Amsterdam, Netherlands

Feb 2011 - Feb 2013

University of Amsterdam Business School

Pre-Master of Science · Business Studies · Netherlands

Oct 2000 - Jul 2006

Hogeschool Inholland

Bachelor of Applied Science · Business Informatics · Diemen, Netherlands

Certifications & licenses

Python Developer

SQL Developer