About

Turning complex data into clearer decisions

I work at the intersection of marketing analytics, attribution, and data modeling—helping teams invest smarter with rigorous analysis and trustworthy pipelines.

Profile photo of Karen Ostdiek

Hello and welcome. I’m a Principal Business Intelligence Analyst based in Boston, Massachusetts, focused on marketing and product analytics—and I’ve been taking on more machine learning work as well. I build attribution models, ROI reporting, and the Snowflake/dbt pipelines that make those answers reproducible.

One recent ML project: a social listening relevance model. Our feed had a lot of noise (for example, competitors whose names are common words). I used an LLM to generate truth labels on a subset of posts, then trained a TF–IDF + logistic regression classifier to label the rest of the dataset and score new data as it arrives—so the team gets cleaner signal without hand-labeling everything.

Before my current role, I worked in health-plan risk adjustment—reconciliation, regulated submissions, and analytics in Snowflake, dbt, Airflow, and Python. My foundation is a Ph.D. in nuclear physics from Notre Dame: experimental design, careful measurement, and communicating results to both experts and general audiences.

Most of my recent work lives in private repositories; below you’ll find anonymized project summaries. My public code is on GitHub. I’m always happy to connect on LinkedIn or via the contact form.

Thank you for visiting.


Capabilities

Skills

A deliberately unscientific chart—because humility and humor belong on a résumé too.

  • Know-it-all
    Fairly Confident
    Get done what I need to
    Enough to be dangerous
    Just the Basics
  • SQL /
    Snowflake
  • dbt
  • Git /
    GitHub
  • Python
  • ML
  • Excel
  • Tableau
  • SAS
  • Currently working in
  • Off and on
  • But it’s been a while

Selected work

Projects

Representative themes from my work. Details are anonymized where code and data are proprietary.

Social listening relevance (ML)

Noisy text · LLM labels · classical ML at scale

Social listening data was cluttered with irrelevant mentions—e.g. competitors whose names are common words.

Created gold-standard labels on a subset using an LLM, then trained a TF–IDF + logistic regression model to classify the full historical set and score incoming posts automatically.

Outcome: Higher-precision relevance signal for reporting and follow-up without labeling every row by hand.

Python scikit-learn TF–IDF LLM labeling

Marketing ROI & attribution

Problem → Approach → Outcome

Stakeholders needed a consistent view of how paid and lifecycle campaigns translated into revenue.

Built and iterated ROI reporting and a rebuilt attribution data model in Snowflake and dbt (with modern git-based workflows), aligning analytics to a major CRM transition.

Outcome: More credible campaign decisions and a durable foundation for downstream reporting.

Snowflake dbt SQL

SMS line forecasting

Forecasting · cross-functional adoption

The business needed an agreed revenue forecast for the SMS line of business to align company-wide planning.

Partnered with stakeholders to develop and socialize forecasts grounded in usage, churn, and upgrade behavior—translating complex time series into numbers leadership could adopt as targets.

Outcome: Forecast adopted as a primary planning benchmark.

Forecasting Python SQL

Regulated health-plan analytics

Medicare Advantage · data quality

Submissions for government programs required tight reconciliation between operational systems and reporting.

Maintained analytical layers in Snowflake; collaborated across engineering and data science on pipelines (GitHub, CircleCI, Airflow, dbt) and surfaced issues through dashboards and deep dives.

Outcome: More reliable submissions and faster insight into risk-adjustment performance.

Snowflake dbt Airflow

Background

Experience & education

Principal Business Intelligence Analyst

Klaviyo · Boston, MA

April 2023 – present

  • Drove revenue growth through insights from marketing and product analytics for major initiatives such as Black Friday/Cyber Monday, supporting optimized strategies.
  • Developed a comprehensive Marketing ROI report that helped Marketing optimize digital campaigns and revenue.
  • Created a robust attribution data model using Snowflake, dbt, and Cursor following a major Salesforce redesign—improving accuracy and enabling advanced analytics.
  • Built predictive multipliers for LTV/CAC analyses so teams could invest with clearer tradeoffs.
  • Mentored junior analysts on the marketing analytics team and strengthened cross-functional collaboration.

Senior Business Intelligence Analyst

Klaviyo · Boston, MA

October 2021 – April 2023

  • Delivered ongoing Marketing ROI analysis for paid media, including LTV, CAC, and Magic Number views.
  • Developed a revenue forecast for the SMS line of business that was adopted as a primary company-wide planning target.
  • Supported SMS with deep dives on net churn, upgrades, usage, and MRR.

Senior Risk Adjustment Data Analyst

Devoted Health Plans · Remote / Watertown, MA

August 2019 – September 2021

  • Performed error reconciliation on data submitted for Medicare Advantage regulations, impacting month-over-month revenue.
  • Built and maintained analytical tables in Snowflake within a pipeline using GitHub, CircleCI, Airflow, and dbt.
  • Supported operations with KPI dashboards, exploration, and modeling in SQL, Python, and Sisense.

Risk Adjustment Data Analyst

PacificSource Health Plans · Eugene, OR

April 2017 – August 2019

  • Cut report production time by roughly half for hundreds of monthly reports by revamping SAS and Excel VBA.
  • Reduced submission rejections to under 1% by improving error reports and documenting process fixes for regulated submissions.

Volunteer

April 2017 – August 2019

United Way Day of Caring and company garden work—produce donated to a local food bank.

Emergency Preparedness Editor

2016 – 2017

Edited a county Emergency Operations Plan for grammar, spelling, and style.

Ph.D. in Physics

University of Notre Dame · Notre Dame, IN

August 2016

  • Resolved an open discrepancy in the field; communicated results through publications and presentations for experts and the public.
  • Authored C++ and Python software to measure rare-isotope decay rates while controlling contamination; LabView control of magnets and detectors.
  • Mentored junior researchers in experimental technique and data analysis.

Volunteer

2010 – 2016

Nuclear Science Lab tour guide for students, scouts, and officials. Coordinator for Physics Olympics across universities.

B.S. in Physics & Mathematics

University of Wisconsin–Stevens Point · Stevens Point, WI

May 2009

Resident Assistant

2007 – 2009 · University of Wisconsin–Stevens Point


Contact

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