
David Castillo
Analytics Engineer · dbt · SQL · Snowflake · Airflow
(718)-415-6767
Building reliable data foundations for teams that run on good decisions.
Hey, I'm
David
About Me
MY BACKGROUND
I'm a first-generation Mexican/Dominican American and the first college graduate in my family. My path to analytics engineering started in the service industry, moved through retail management at T-Mobile, and took a sharp left turn when a financial analysis class during my MBA sparked an obsession with data. I quit my job, sold my car, and enrolled in General Assembly's Data Science bootcamp. No safety net, just pure commitment.
Since then I've built production analytics systems at Dow Jones and Kaiyo; leveraging dbt models, ELT pipelines, dimensional data marts, and the kind of clean data layer that lets teams stop arguing about numbers and start acting on them. I mix business accumen with an engineer's rigor to every problem, which means I care as much about whether the insight is useful as whether the pipeline is correct.
Today I'm open to full-time Analytics Engineering roles and select consulting engagements. If you're building a data team or need help getting your analytics stack into shape, I'd love to connect.
Experience
WHERE I’VE WORKED
Dow Jones, Senior Data Analyst
Jul 2023 – Current
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Developed and maintained analytics-ready datasets and dbt models, integrating multiple data sources into a centralized reporting layer used by analysts, finance, and product stakeholders
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Defined complex SQL business logic to standardize metric definitions across teams, improving data accuracy and enabling more reliable decision-making
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Implemented automated data validation and monitoring checks, reducing data errors by ~31% and contributing to a 48% increase in realized monthly revenue; identified and resolved a 6–7 figure revenue discrepancy by redesigning pipeline logic
Kaiyo, Analytics Engineering Apprentice
Jan 2023 – Jun 2023
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Built modular dbt models transforming raw operational and financial data into analytics-ready datasets, enabling cross-functional reporting and operational insights
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Deployed data quality tests to improve confidence in datasets and prevent costly downstream errors, maintaining zero overpayments to clients
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Collaborated with stakeholders to translate business requirements into well-documented, reusable data models; contributed to on-time delivery improving from ~92% to ~97%
T-mobile, Manager
Jul 2013 – Oct 2021
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Built KPI reporting frameworks using Power BI and Excel, consistently driving teams to ~105% of target
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Implemented data-driven process improvements that reduced customer escalations by ~15%
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Developed foundational skills in stakeholder communication, operations, and translating data into actionable decisions
Education
WHAT I’VE LEARNED
General Assembly Data Science Fellow
Nov 2021 - Feb 2022
University of Arizona GC, MBA
Dec 2019 - Mar 2021
Masters of Accountancy
CUNY (Lehman College), BA
Aug 2006 - May 2010
Political Science
Skills
Analytics Engineering
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dbt
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SQL
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Dimensional Modeling
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Semantic/Metric Layers
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Git
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CI/CD
BI & Visualization
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Looker
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Redash
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Looker Studios
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Dashboard Development
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Self-Service Analytics
Data Platforms & Pipelines
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Snowflake
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BigQuery
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Redshift
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GCP
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Python
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ELT Design
Soft Skills
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Stakeholder Communication
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Cross-functional Collaboration
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Problem Solving
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Adaptability
Interests
OUT OF OFFICE
Coffee
NBA
Scifi/comics
Yoga
Reading
Film