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Turn raw data into reliable decisions

SQL & Data Engineering

Practice SQL, relational modelling, query performance, pipelines, and data-quality reasoning for analytics and engineering roles.

Best for: Backend, analytics, data, and AI candidates who need strong data foundations.

This week

Repair the hiring funnel report

Correct joins, remove duplicate counts, and choose indexes for a broken analytics query.

Take the challenge →

Coding checks

The first practical coding set will focus on:

SQL joins
Window functions
Schema design
Pipeline validation
Coding Beta is rolling out track by track.

What you will prove

Write correct analytical SQL
Model transactional data
Diagnose slow and unreliable pipelines