query.lab

~/learn

Learn data skills, one small step at a time

Short lessons, real tables, and code you can run right on the page — no setup, no install. Pick a goal below and we'll show you where to start.

tracks7
lessons114
done0

1 · what do you want to do?

SQL path

Query databases & build reports

Aspiring data / business analysts

SELECT → filter → group → join → rank

  1. Milestone 1 · Foundations3 ch
  2. Milestone 2 · Real-world data3 ch
  3. Milestone 3 · Interview-ready3 ch

basics ~27 min · 0/18Start with SELECT

Python path

I'm brand new to programming

Complete beginners — learn to code first

values → decisions → loops → collections → reusable programs

  1. Milestone 1 · Foundations2 ch
  2. Milestone 2 · Real-world data3 ch
  3. Milestone 3 · Interview-ready2 ch

basics ~84 min · 0/23Start with variables

Pandas path

Clean spreadsheets & analyse data

Excel users moving to code

load → inspect → filter → group → merge → clean

  1. Milestone 1 · Foundations2 ch
  2. Milestone 2 · Real-world data3 ch
  3. Milestone 3 · Interview-ready2 ch

basics ~13 min · 0/13Start with DataFrames

Machine Learning path

Ace ML theory interviews

Data scientists & ML engineers

frame → validate → measure → model → engineer → ship

  1. Milestone 1 · Foundations2 ch
  2. Milestone 2 · Real-world data2 ch
  3. Milestone 3 · Interview-ready1 ch

basics ~36 min · 0/15Start with paradigms

A/B Testing path

Run & read A/B tests

Product analysts & data scientists

hypothesise → size → randomise → check → analyse → decide

  1. Milestone 1 · Foundations2 ch
  2. Milestone 2 · Real-world data1 ch
  3. Milestone 3 · Interview-ready2 ch

basics ~27 min · 0/15Start with the lifecycle

ML System Design path

Ace ML system design rounds

ML engineers & applied scientists

frame → data → retrieve → rank → serve → monitor

  1. Milestone 1 · Foundations2 ch
  2. Milestone 2 · Real-world data1 ch
  3. Milestone 3 · Interview-ready2 ch

basics ~32 min · 0/15Start with the framework

Product Metrics path

Crack product metric case rounds

Product analysts & data scientists

define → decompose → segment → diagnose → trade off → recommend

  1. Milestone 1 · Foundations2 ch
  2. Milestone 2 · Real-world data1 ch
  3. Milestone 3 · Interview-ready2 ch

basics ~30 min · 0/15Start with North Stars

Not sure where to begin?Take the 3-minute SQL check and get a personal 7-day study plan.

2 · how every lesson works

  1. 01

    Read

    A short explanation with a picture of what happens.

  2. 02

    Look

    See the real tables before you write anything.

  3. 03

    Try

    Edit and run the examples right on the page.

  4. 04

    Practise

    Solve a matching problem to lock it in.

3 · looking for something specific?