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David Castillo

Analytics | Data Orchestration | Insights
 

dcast822@outlook.com

(718)-415-6767

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Hey, I'm

David 

About

About Me

MY BACKGROUND

I am a first-generation Mexican/Dominican American and also the first college graduate in my family.  My journey has taken me from working in the service industry as a barista while I helped pay my way through college and then working my way up to a retail sales management role. These roles really helped me cultivate skills in communication, collaboration, problem-solving while identifying the needs of different stakeholders.

My education culminated in Data Science where I first learned technical skills in Python & SQL to develop predictive and classification models. The pivot to Data Science occurred after taking a financial analysis class while earning my MBA, using quantitative analysis for financial reports. I soon learned that with Data Science you can use a variety of analytical techniques to derive insights using a variety of tools on a variety of datasets at tremendous scales.   I found myself locked in and teaching myself the basics of Python and Pandas.  At that moment I knew this was what I wanted to do.  I joined General Assembly's Data Science bootcamp and punctuated the commitment by quitting my job and selling my car.  There is no doubt I am extremely passionate & committed to data.  

Since then I have been able to apply my technical acumen and craft as an Analytics Engineer in startup and corporate environments.  I have been able to learn about various ways of ingesting data, transforming it, testing it and producing insights through reports and dashboards.  Here I realized my passion is in the various ways you can work with data

Education & Experience

Education

WHAT I’VE LEARNED

Experience

WHERE I’VE WORKED

Dow Jones, AdOps Analyst
General Assembly, Data Science Fellow
Nov 2021 - Feb 2022

12-weeks, about 500-hour program dedicated to data analysis, make sense of, convey data-driven facts from large data sets, and predict trends through predictive modeling and inference.

University of Arizona GC, MBA
Dec 2019 - Mar 2021

Masters of Accountancy                                    GPA: 3.7

CUNY (Lehman College), BA
Aug 2006 - May 2010

Political Science                                              GPA: 3.4

Jul 2023 – Current
  • Automated various repeated procedures into modular tables, utilizing BigQuery, Scheduled Queries and SQL, resulting in modular tables that helped increase query speeds by ~3X, also reducing SQL code lines written.

  • Developed reporting dashboard for all programmatic advertising data, utilizing GAM API, Python, Airflow, BigQuery, SQL, Looker Studios, which utilizes data pipeline to help track various disparate revenues cut across various segments from all programmatic channels.  Dashboard utilized by various stakeholders including executives, sales, planning and operational teams to align source of truth across these departments and personnel.

  • Helped reconcile data discrepancies, utilizing GAM UI, GAM API, Python, BigQuery, SQL, Looker Studios for Tax Revenue and Video Advertising Dashboards, reducing discrepancies from ~20% to ~.05% due to fixing how the data was aggregated and then joined.

Kaiyo, Analytics Engineering Intern
Jan 2023 – Jun 2023
  • Provided ad hoc analysis & reporting, using DBT, SQL (Redshift) and Redash, to aid operations team in optimizing durations through various activities segments related to receiving and maintaining incoming furniture to make ready for sale, leading to a decrease of overall durations by ~12%.

  • Built, documented & tested data models, used for various departmental analysis such as addressing overpayments from revenue share from furniture sales, utilizing DBT, Stitch, and SQL, resulting in maintaining 0 overpayments to clients.

  • Constructed queries via large datasets from warehouse, for alerts, dashboards, and data visualizations, utilizing DBT, SQL(Redshift), and Redash, to help departments improve processes such as modeling routes and their on-time delivery frequency, helping to increase on time delivery performance from ~92% to ~97% on time rate.

T-mobile, Manager
Jul 2013 – Oct 2021
  • Conducted workshops on best practices for sales, using Dale Carnegie and Kaizen principles, leading to ~15% less escalations from the prior year and a decrease in ~$1.5K in credits.

  • Established metrics for the sales team, using Power BI and Excel, resulting in 5 goals met at ~105% of target.

  • Ensured compliance with the Operations Department leading to the resolution of discrepancies that shifted losses from my company to the logistic company in the average amount of ~$15K a year.

  • Conducted training, using Dale Carnegie principles, and Kaizen, leading to 40+ personnel having promotions or improving ability to meet their targets.

Skills & Languages

Skills

Technical

Interpersonal

  • Python

  • SQL

  • Seaborn

  • Matplotlib

  • Linear/Logistic Regression

  • kNN

  • Decision Trees

  • Bagging/Boosting Models

  • cross-validation

  • bootstrapping

  • Grid-search

  • NLP (TF-IDF, count-vectorizer)

  • Keras

  • Problem Solving

  • Critical Thinking

  • Adaptability

  • Emotional Intelligence

  • Active Listener

  • Communicate to various stakeholders

  • Positive client relations

  • Collaboration

Awards & Interests

Interests

OUT OF OFFICE

Coffee

NBA

Scifi/comics

Yoga

Reading

Film

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