OpenEDG PCAD case studies
OpenEDG PCAD · Put your knowledge to work in context.
PCAD – Certified Associate Data Analyst with Python is the associate-level credential in the Python Institute's Data Science track, positioned between the entry-level PCED and the professional-level PCPD (still in development). It validates practical data analysis skills at junior to intermediate level: acquiring and integrating data from databases, APIs and web content; cleaning and validating it; exploring and analyzing it with Pandas and NumPy; querying structured data with SQL and connecting Python scripts to databases; applying descriptive and inferential statistics; building and evaluating foundational regression models; communicating findings with Matplotlib and Seaborn; and following sound programming practices (object-oriented design, exception handling) and ethical data handling. The OpenEDG PCAD case studies are 5 cases and about 2,421 words.
1Catalog Sync with a Flaky Partner API
A retail analytics team must refresh a product catalog every morning by combining a partner REST API with an internal PostgreSQL table. The API returns 100 records per page with cursor pagination, enforces 60 requests per minute, and serves about 48,000 SKUs.
532 words, about 3 min2Cleaning a Multi-Region Signup Extract
An e-commerce team receives a 25,000-row customer signup CSV assembled from three regional forms. Columns are email, signup date, region, age, and marketing opt in.
469 words, about 2 min3March MRR Reconciliation Across SQL and a Price Catalog
A SaaS finance team asks for March MRR from two sources: a PostgreSQL table subscriptions(subscription id, account id, plan id, start ts, end ts, status) with 120,000 rows, and plan catalog.csv(plan id, monthly price, currency, effective from) with 14,000 rows because prices changed over time. Timestamps are stored as UTC except 3,000 rows loaded from a legacy system that used local time (UTC-5).
492 words, about 2 min4Borderline A/B Test and a Leaky Conversion Model
An online retailer tested a redesigned checkout for 14 days. Control had 8,100 users and 502 conversions; treatment had 8,050 users and 563 conversions.
464 words, about 2 min5No-Show Dashboard, PII, and a Misleading Chart
A public hospital analytics team is building a dashboard from appointment records. The table contains patient id, full name, date of birth, ZIP code, appointment date, department, no show flag, and free-text notes.
464 words, about 2 min