The Library · Insights
Deep dives across data, automation & AI
983 in-depth articles — from Excel foundations to production machine learning. Filter by topic or difficulty to find exactly what you need.
Data EngineeringPractitioner
Handling Late-Arriving and Out-of-Order Data in Production Pipelines: Reprocessing, Grace Windows, and Correction Strategies
Late data isn't an edge case — it's a property of every real production pipeline. This lesson teaches you the complete toolkit: watermarks, grace windows, idempotent reprocessing with Delta Lake, and correction strategies that cascade downstream without breaking anything.
22 min read
AI & Machine LearningPractitioner
Reciprocal Rank Fusion: Merging Multiple Retrieval Results into a Single Ranked List for Hybrid RAG Pipelines
Hybrid RAG pipelines combine keyword and semantic search — but merging their results without breaking both is harder than it sounds. This lesson teaches you Reciprocal Rank Fusion from the formula up through a complete, production-ready Python implementation, so you can build retrievers that outperform either approach alone.
23 min read
AI & Machine LearningPractitioner
Building a Citation and Source Attribution System for RAG: Linking LLM Responses Back to Source Documents with Confidence Scores
Most RAG systems retrieve documents and generate answers — but never connect the two in a way users can actually trust or verify. This lesson builds a complete citation pipeline that maps every LLM claim back to a specific source chunk, complete with composite confidence scores and hallucination detection.
20 min read
AI & Machine LearningPractitioner
AI-Assisted Data Cleaning: Using LLMs to Standardize, Deduplicate, and Validate Messy Datasets
Messy data doesn't just waste time — it poisons every analysis downstream. Learn how to build a Python pipeline that uses LLMs for the parts of data cleaning that require real judgment: normalizing company names and job titles, catching semantic duplicates that fuzzy matching misses, and validating records for logical consistency.
22 min read
SQLPractitioner
Writing Effective SQL Unit Tests: Validating Query Logic, Edge Cases, and Data Contracts in CI/CD Pipelines
SQL bugs don't throw exceptions — they return wrong answers silently. This lesson teaches you how to build a complete SQL unit testing strategy using fixture data, edge case coverage, data contracts, and CI/CD integration with dbt and GitHub Actions.
24 min read
Power AutomatePractitioner
Building Power Automate Flows for Microsoft 365 Group and SharePoint Permission Management
Manual permission management in Microsoft 365 is slow, inconsistent, and impossible to audit at scale. This hands-on lesson walks you through building a complete automated permission management system — from approval-gated access requests to M365 Group provisioning and scheduled access reviews — using Power Automate, Graph API, and SharePoint REST API.
21 min read
Power AppsPractitioner
Canvas App Bulk Data Operations: Multi-Record Patch, ForAll Processing, and Progress Tracking for Large Dataset Updates
Learn how to handle bulk data operations in Power Apps Canvas Apps without freezing the UI or hitting API throttle limits. This lesson covers the table-form Patch pattern, chunked ForAll processing, real-time progress tracking, and error handling for partial failures — everything you need to build production-quality bulk update screens.
19 min read
Power BIPractitioner
Implementing Power BI Cross-Report Drillthrough and Shared Bookmark Strategies to Build Interconnected Enterprise Report Ecosystems
Stop treating Power BI reports as isolated artifacts. This lesson teaches you how to design cross-report drillthrough and shared bookmark strategies that turn your entire report collection into a connected analytical ecosystem — with context flowing seamlessly between reports, teams, and data domains.
22 min read
Power BIPractitioner
DAX Ranking Patterns in Practice: RANKX, TOPN, and Dense vs. Sparse Rankings Across Dynamic Filter Contexts
Ranking in DAX looks simple until your measures start returning 1s everywhere or skipping ranks inexplicably. This lesson builds a complete, production-ready understanding of RANKX and TOPN — including category-relative rankings, dynamic top-N leaderboards, and how to diagnose ranking failures across changing filter contexts.
20 min read
Power BIPractitioner
Mastering Power BI Field Parameters: Dynamic Axis Switching and Metric Selection for Flexible Self-Service Reports
Field Parameters let you build reports where users dynamically swap dimensions and metrics without you touching the report again. Learn how they work at the DAX level, how to customize them beyond the wizard, and how to combine dimension and metric selectors in a single production dashboard.
19 min read
Power QueryPractitioner
Custom Pivot and Unpivot in Power Query M: Dynamic Column Detection and Multi-Attribute Reshaping
The native Pivot and Unpivot buttons in Power Query break the moment your source schema changes. This lesson teaches you how to write M code that detects columns at runtime, handles multi-attribute unpivot, and builds custom aggregations that go far beyond what the UI can do. Walk away with production-ready patterns you can deploy immediately.
17 min read
Power QueryPractitioner
Implementing Slowly Changing Lookup Tables in Power Query: Point-in-Time Merges with Effective Date Ranges
When reference data changes — customer segments, sales territories, product categories — a simple merge applies today's values to all your historical records. This lesson shows you exactly how to build a slowly changing lookup table with effective date ranges and merge it correctly in Power Query for accurate point-in-time reporting.
21 min read