reporting
Why You Should Not Average Margin Percentages
Calculate overall gross margin correctly in Excel and Google Sheets. See why averaging percentages gives 55% when the business earned 25.90%, and how to fix it.
Data Analytics · Systems · AI Engineering
Decades of Experience. A Modern, Data-Driven Approach.
Leveraging a career that spans manufacturing, education, and urban mobility, I specialize in solving complex challenges. My focus is on using data to find clarity and drive measurable growth, regardless of the industry.
Grain First
Table & Metric Clarity
4 Pillars
Metrics · Data · Reporting · Ownership
AI + Ops
Production Systems & RAG
analytics-workbench — Live Preview
Interactive01 · Grain FirstVERIFIED
Define What One Row Represents Before Counting
Conflicting totals usually start when spreadsheets mix orders, line items, and payments in the same view. Declaring the table grain first restores trust in every downstream metric.
Grain: 1 row per completed_order_id (net of refunds, UTC close)
Case Studies & Production Systems
Systems built for operational clarity and measurable outcomes.
Selected case studies across business development automation, educational transformation, and AI-assisted career learning.
Next.js · Supabase · AI
CareerTalkLab
An existing English-learning LMS, with a wider data and software career-learning direction planned.
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Operations · EdTech
Digital Transformation in Crisis
Leading a language school's complete pivot to online learning during COVID-19.
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Python · AI Pipeline
BD Automation Suite
A modular Python pipeline that automates multi-stream business development, from prospect research to AI-drafted outreach.
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Operator & Builder Perspective
Real-world operations meet disciplined data and AI systems.
With a unique blend of hands-on manufacturing expertise, educational leadership, and data analytics skills, I bring a comprehensive perspective to every project. My approach combines decades of real-world experience with modern technological solutions to deliver tangible results.
About Me
Focus AreasSMB Analytics · Grain First · AI
MethodologyClear Definitions & Owned Action
Community LabCareerTalkLab (A1–C1 + Data)
Writing & Field Notes
Practical essays on small-business analytics, Grain First, and building CareerTalkLab.
Field notes on turning messy spreadsheets into reliable decisions, alongside essays on AI engineering and language pedagogy.
reporting
Percentage Change vs. Percentage Points in Business Metrics
Use percentage change for dollar and unit totals, and percentage points (pp) for metrics that are already percentages. Here are the exact Excel and Google Sheets formulas and custom number formats.
reporting
Compare Monthly Sales When Trading Days Differ
Compare monthly sales fairly with sales per open day. Count actual trading days in Excel or Google Sheets, handle closures, and separate calendar effects from daily averages.