When people talk about feature engineering, SQL is often treated as a second-class citizen.
You’ll hear things like:
If you’ve worked in BI or analytics long enough, you’ve probably heard people talk about models as if they were something mysterious.
“Once we build a model, we can predict this.”
“The model says this user will churn.”
“We need a better model for this problem.”
If you’ve ever run an A/B test, you’ve probably seen this happen:
As a data analyst, you’re probably very comfortable working with SQL tables, CSV files, and Excel spreadsheets. But sooner or later, you’ll run into a situation like this:
If you work with data — in analytics, BI, or data engineering — you’ve probably heard the term dbt (pronounced “dee-bee-tee”). It has become one of the most popular tools in the modern data stack because it empowers analysts to build production-grade data pipelines using just SQL.
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A/B testing (or split testing) is one of the most powerful tools in an analyst’s toolbox: it allows you to compare two (or more) versions of a web page, feature, or user experience — and determine which version truly performs better.
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When building data-driven solutions — whether dashboards, reports, or analytical pipelines — you often focus on selecting, transforming, or visualizing data. But to make all that work, you need a well-structured database behind the scenes. That’s where Data Definition Language (DDL) comes in.
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JSON (JavaScript Object Notation) has become the universal language for exchanging data between applications. Whether you’re pulling data from APIs, storing logs, or dealing with semi-structured data in a data lake — JSON is everywhere.
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Have you ever imported a dataset into Tableau, Power BI, Looker Studio, or Qlik Sense—only to find that several identical rows suddenly appear as one?
If so, you’ve likely encountered BI tool data deduplication, a fundamental behavior across nearly all modern Business Intelligence platforms.
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If you work with data long enough, you’ll eventually face the classic “Why does my number look weird?” problem.
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