# Data analytics & BI · experience and example brief

Richie Lin · Experience and work samples

I use Python and SQL to explore records, validate totals, and communicate business findings. My portfolio includes a public data explorer with a downloadable source and verification script.

## Relevant experience

### Data analysis & validation

Analyzed 440 records with Python, pandas, and scikit learn, reconciled totals in SQLite, and built a Plotly dashboard.

Working principle: Validate totals at each stage from raw records to the dashboard.

Case: https://richielin.com/pages/customer-segmentation

### Business reporting

Validated SQL joins for 99 products and developed a five KPI HTML/Chart.js dashboard.

Working principle: A useful dashboard connects a metric to the decision it informs.

Case: https://richielin.com/pages/breaking-games

## Illustrative brief · proposed approach

Two dashboards disagree on revenue. How would I investigate?

Inputs: Metric definitions, SQL queries, reporting dates, joins, and source totals.

1. Compare definitions, exclusions, date boundaries, and the grain of each report.
2. Reconcile totals before and after each join to isolate missing or duplicated records.
3. Document the cause and propose a shared definition with a repeatable validation check.

Proposed deliverable: A reconciliation report and a documented metric definition.

Evaluation: The revised outputs reconcile to the agreed source under the same filters.

## Related methods and exercises

- SQL report reconciliation (Illustrative sample · Synthetic data): https://richielin.com/pages/samples/sql-quality-check
- Customer purchasing mix memo (Public data analysis · Portfolio companion): https://richielin.com/pages/samples/customer-insight-memo

## Context

The published dashboards use Plotly and HTML/Chart.js. Tableau and Power BI are additional tools. Native workbooks are not included here.

The proposed brief is a planning exercise. Each linked method includes its data or assumptions.

Role titles: Data Analyst Intern · Data Analytics Intern · Business Intelligence Intern · BI Analyst Intern

Contact: richielin02@gmail.com
Online: https://richielin.com/pages/roles/data-analytics-bi