Editions of The Data Dose

_*]:min-w-0"> Hey - Tom here. _*]:min-w-0"> If you've ever Googled "Git vs GitHub" and walked away more confused than when you started, I get it. I was there once. _*]:min-w-0"> Once you grasp what each tool actually does, version control becomes a skill that makes you significantly more h...

by Tom Mitchell — Oct 31, 2025 analytics-engineering data-engineering git github version-control workflow

What actually happens in a SQL technical interview?

Hey - Tom here. Sooner or later, if you want to work in data, you'll need to take part in a SQL technical interview. Weirdly, most candidates turn up underprepared for what actually gets tested. This style of interview isn't just testing if you can write SQL - it's testing how you think through p...

by Tom Mitchell — Oct 24, 2025 analytics engineering career development data analytics sql interviews sql skills technical interviews

If CTEs and Subqueries confuse you, read this

Hey — Tom here. CTEs and subqueries are similar things: they let you perform "on the fly" subsets of data and integrate them into queries like you would with tables. So why do we have two ways to do it? More importantly, when should you use each one? Here's what we're covering this week: What CT...

by Tom Mitchell — Oct 17, 2025 analytics-engineering best-practices cte data-engineering sql

The 3 skills that got me promoted from analyst to senior analyst

Hey — Tom here. Most analysts think getting promoted is about becoming more technical. They chase advanced certifications, learn exotic tools, and dive deeper into complex statistical methods. Meanwhile, the person who gets the senior analyst role is usually the one who's mastered three fundament...

by Tom Mitchell — Oct 10, 2025 analytics engineering business intelligence career development data analytics stakeholder communication

Airflow explained in 3 minutes

Hey — Tom here. Apache Airflow is becoming the standard for managing data pipelines, and understanding it isn't optional anymore. Big companies expect data professionals to know how workflows fit together, even if you're not the one building them. That's why they pay the highest salaries. Here's ...

by Tom Mitchell — Oct 03, 2025 apache-airflow automation data-engineering data-pipelines etl workflow-orchestration

The easy way to clean data in Python

Hey — Tom here. Nothing kills an analysis faster than messy data. You've got duplicates, missing values, inconsistent formats, and columns that make no sense. Before you know it, you're spending 80% of your time wrestling with data instead of extracting insights from it. Python makes data cleanin...

by Tom Mitchell — Sep 26, 2025 analytics-engineering data-cleaning data-quality data-validation pandas python

How to present data confidently in 3 simple steps

Hey — Tom here. You know that sinking feeling when your boss asks you to "present the findings" to the leadership team? Your palms get sweaty. Your mind goes blank. Suddenly, all those charts and insights you've been working on feel like a foreign language you're about to butcher in front of the ...

by Tom Mitchell — Sep 19, 2025 analytics business intelligence data communication data presentation data storytelling frameworks

Star vs snowflake schema: everything you need to know

Hey - Tom here. If choosing between star and snowflake schemas feels overwhelming, you're not alone. This fundamental decision has long-term implications for performance, cost, and maintainability. Today, I'm sharing a simple breakdown from my experience at large companies (spoiler: there's no "o...

Sep 12, 2025 analytics-engineering data-architecture data-warehouse database-design dimensional-modeling olap-design schema-design snowflake-schema star-schema

If SQL JOINs confuse you, read this

Hey - Tom here. SQL JOINs trip up more beginners than any other concept I teach. You write what seems like a perfectly reasonable query, then boom - either zero results when you know data exists, or millions of rows when you expected hundreds. The problem isn't that JOINs are complex. It's that m...

by Tom Mitchell — Sep 05, 2025 data analysis database query optimisation sql tutorial

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