Built by an Ex-Google Growth Data Scientist on the YouTube Growth Team

SQL for Real | Analytics— the FAANG Way

Practice SQL on real business datasets — with AI feedback that evaluates production readiness, not just correctness. Most platforms teach you syntax. Queryflo trains you to think like a domain expert.

100
SQL Challenges
7
Business Domains
4
AI Tutors
3
Difficulty Levels
queryflo.ai/challenges/42
Queryflo
SQL for Business
Dashboard
Challenges
Text to SQL
Data Sandbox
Learn
Growth Analytics
Progress
GrowthIntermediateCohort Retention at Month 3
3 / 20
Your Task
Using the cohort_retention table, find the month-3 retention rate for each cohort.
SQL Editor
⌘+Enter to run
SELECT cohort_month,
period_number,
ROUND(retained::numeric / users * 100, 1) AS retention_rate
FROM growth.cohort_retention
WHERE period_number = 3
ORDER BY cohort_month
Correct · 8 rows+20 XP
cohort_monthperiod_numberretention_rate
2024-01-01334.2
2024-02-01331.8
2024-03-01336.5
AI Feedback
Great use of type casting! ::numeric ensures decimal division. Month-3 retention above 30% signals strong product-market fit.
Code Review
✅ Clean Code: No SELECT *, type-safe division, schema-prefixed table. Consider a HAVING clause to filter noise.
Insight
Jan cohort retains best at 34.2% — likely your strongest ICP. Feb dip to 31.8% warrants investigation into that month's acquisition channel.
The Problem

Most SQL prep doesn't prepare you for business interviews

FAANG data interviews don't test whether you can write a JOIN — they test whether you can turn messy business data into a decision. Traditional SQL courses miss this completely.

Generic SQL tutorials use toy databases with no business context

You can write a JOIN but can't explain what the metric means

No feedback on whether your query is production-ready or just "correct"

FAANG interviewers want SQL + business judgment — most prep only teaches syntax

No structured way to learn HEART, AARRR, and A/B testing alongside SQL

The Solution

SQL practice built for the way business analysts actually work

Every challenge in Queryflo is built around a real business scenario. You don't just get "correct" — you get AI feedback on your SQL governance, a data narrative you could present to a VP, and a deeper understanding of the business metric you just computed.

Try it now
Domain-specific schemas
Growth, SaaS, Marketing, Product, Finance, Sales, Web — real business verticals
4 AI tutors per challenge
Explanation, Code Review, Exec Summary, Schema Chat — all streaming
Instant validated feedback
Your output columns are checked against expected results automatically
XP + streak system
Gamified progress tracking across 100 challenges and 3 difficulty levels
FAANG-level difficulty
Window functions, cohort analysis, rolling averages, LTV:CAC, Rule of 40
Responsible AI governance
Every AI feature is transparent, explainable, and aligned with your learning
7 Business Domains

Real schemas. Real business problems.

Challenges span 7 domains, each modelled on how real companies store their data. Every schema covers Beginner, Intermediate, and FAANG-level Advanced difficulty.

Growth
SaaS
Marketing
Product
Finance
Sales
Web
Beginner

SELECT, WHERE, GROUP BY, JOINs, aggregations

Intermediate

CTEs, subqueries, date functions, complex joins

Advanced

Window functions, cohort analysis, LTV:CAC, Rule of 40

How It Works

From question to production-ready SQL in 4 steps

01

Pick a challenge

Choose from 100 challenges across 7 domains and 3 difficulty levels. Filter by domain or difficulty.

02

Write your SQL

VS Code-quality Monaco editor with SQL syntax highlighting. Use the schema panel to understand the data model.

03

Get validated

Your result columns are checked automatically. The system knows if you're right — no manual comparison needed.

04

Learn from AI

4 AI tutors analyze your query: explain it, review governance, summarize the insights, and answer schema questions.

AI-First Platform

Not one AI tutor. Four.

Built on Claude (Anthropic) with responsible AI governance. Every AI feature is transparent, explainable, and designed to build your understanding — not replace it.

Answer Explanation

Streams a structured breakdown of the correct approach — what SQL concepts were used, why they work, and what the business metric means in context.

Code Reviewer (Governance)

Auto-runs after every correct query. Checks for SELECT *, missing LIMITs, implicit joins, NULL handling gaps, and non-SARGable predicates.

Exec Summary & Insight

Turns your query results into a CEO-level narrative — key findings, trend identification, and a business recommendation. The skill interviewers actually test.

Schema Explorer (Ask the DB)

Chat with an AI that knows your challenge's schema. Ask 'How do I join these tables?' or 'Which column stores churn date?' and get schema-aware answers.

Text to SQL + AI Judge

Paste a schema, ask in plain English, get SQL. Then run the 8-step AI Judge for Accuracy, Efficiency, and Readability scores out of 10.

Synthetic Data Generator

Describe any business scenario. Get a full practice dataset with CREATE TABLE, INSERT statements, and example queries — generated instantly.

Everything You Need

One platform. Complete SQL mastery.

100 Real-World SQL Challenges

Authentic business schemas — growth analytics, SaaS metrics, marketing funnels, product events, and FP&A finance. The same data models used at FAANG companies.

AI-Powered Feedback Engine

Four AI assistants built into every challenge: Answer Explanation, Code Reviewer (SQL governance), Exec Summary (data storytelling), and Schema Explorer (Ask the DB).

Text to SQL + AI Judge

Paste your schema, ask in plain English, get production-ready SQL — then run the 8-step AI Judge review: Accuracy, Efficiency, and Readability scored out of 10.

Synthetic Data Sandbox

Describe any business scenario and generate a complete practice dataset — CREATE TABLE, INSERTs, and 3 example queries — ready to run immediately.

SQL Guides Library

44 topics categorized as Beginner, Intermediate, and Advanced — from SQL SELECT to Window Functions — all linked to the challenges that use them.

Growth Analytics Library

Deep-dive reference frameworks: HEART (UX quality), AARRR (user lifecycle), Marketing Acquisition, and Experimentation & A/B Testing.

What Analysts Say

Built for analysts, by analysts

"Finally, SQL practice that feels like real work. The cohort analysis challenges are exactly what I got asked at my Meta loop."

Data Analyst, Meta

"The AI Code Reviewer caught three governance issues in my query I wouldn't have noticed. This is how SQL should be taught."

Growth Analyst, Stripe

"HEART framework + AARRR in the same platform as SQL challenges? This is the only prep tool I needed for my Google PM data round."

Product Manager, Google
Pricing

Simple, transparent pricing

Start free. Upgrade when you're ready to go deep.

Save 30%

Free

$0/ forever

No credit card required. Start practicing immediately.

Get Started Free
  • 5 SQL challenges
  • Daily SQL Task
  • Learn SQL for Business
  • Limited business domains
  • Interactive SQL editor
  • Growth Analytics Guide
  • Limited shareable badges
  • Progress & streak tracking
  • 10 AI credits (Text-to-SQL, Explain, Exec Summary, AI Judge, Ask the DB, Data Sandbox)
  • All 100+ SQL challenges
  • All business analytics domains
  • Unlimited AI access
  • Mock interview
  • Advanced AI tutors
Most Popular

Pro

$14/ mo

Billed annually at $168/yr · Save 30%

  • All 100+ SQL challenges
  • All business analytics domains
  • Unlimited AI access
  • Text-to-SQL + AI Judge
  • AI Explain + Exec Summary
  • Ask the DB — unlimited
  • Mock interview
  • Advanced AI tutors
  • Data Sandbox (synthetic data)
  • Shareable achievement badges
  • Progress & streak tracking
  • Priority feature requests
  • Early access to new content

Teams

Custom

For data teams, bootcamps, and enterprises.

Contact Sales
  • Everything in Pro
  • Team admin dashboard
  • Bulk seat management
  • Group progress analytics
  • Custom challenge sets
  • Private domain schemas
  • SSO / SAML support
  • Dedicated Slack channel
  • Onboarding & training session
  • Invoice billing
  • SLA & security review

No credit card for Free

Sign up and start solving challenges immediately. No billing info required until you upgrade.

7-day Pro trial

Try every Pro feature free for 7 days. Cancel anytime before the trial ends — no charge.

Annual saves $72

Billed at $168/yr instead of $240/yr. Lock in your rate and commit to the grind.

Ready to level up your SQL?

100 challenges. 4 AI tutors. Real business schemas. No credit card required.

Start Practicing Free