Atterna · Cases
SQL practice · business case studies

A number everybody believes. Can you check it?

Be sure of the number before you say it.

Short work cases on a fictional marketplace. Run the obvious query, find the trap in it and make a call the team can act on — about 15–30 minutes each.

Open the case: Bigger baskets? About 17 minutes. Free, no account needed.

How a case goes

  1. 1The obvious queryIt gives a convincing number a colleague already believes.
  2. 2The catchFind what the number hides — before the meeting.
  3. 3An answer you can defendClarify, recount like for like and make the call.

Cases

  1. 1
    Case 1 · 17 min · Free · no account

    Bigger baskets?

    Marketing wants to tell finance that a promo code makes baskets 2.5× bigger. Does the comparison support that plan?

    Clarifying a requestDefining a metricChecking comparison limitsA call you can defend
    Open the case
  2. 2
    Case 2 · 26 min · Case round · Foundations €19

    Who cut our commission?

    Take rate fell by more than a point in the promo week. Finance wants a name.

    Clarifying a requestRatios and averagesBreaking a total downA call you can defendChecking the number on a new question
    Get Foundations
  3. 3
    Case 3 · 27 min · Case round · Foundations €19

    Refunds that don’t add up

    Vera wants to drop the most-refunded products from the December promo. Finance is about to check the numbers.

    Clarifying a requestReconciling with financeWhat a JOIN repeatsTelling a pattern from noiseChecking the number on a new question
    Get Foundations

Case 1 is free

Cases 2–3 are the case rounds in Foundations

Two more work stories: find what the number really counts, check it on the data and defend it before anyone decides on it.

€19Atterna Foundations
one-time · early-access price

Get Foundations

Open case 1 free firstAlso in Atterna Analyst, with Meridian · €59

Who you’ll work with

LK
Luka Kimsenior analyst
VL
Vera Lindcommercial director
TR
Tomás Ruizmarketing
OP
Olga Petrovafinance
Want the long version?

Meridian is the full simulator in Atterna Analyst: eight episodes, each a working week with its own decision.

Meridian
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