Frequently asked questions

caseSQL is a browser-based SQL learning platform where you solve realistic business problems by writing SQL against a hosted PostgreSQL database. Pick a career path — Marketing, Business Intelligence, Provider, Finance, Credit Risk & Banking, AML & Fraud, RevOps, or Ecommerce — and work through missions with messy data, Slack-style stakeholder briefs, and a 5-tier validator that gives graduated manager-style feedback.

No. The first mission on each path eases you in, and every mission includes a progressive hint system if you get stuck.

No. Queries run against a hosted Postgres database on our servers — just open the editor and start writing SQL. A free account unlocks progress tracking and the option to upgrade to Pro later.

PostgreSQL, hosted on Supabase. Your queries run against a real server-side database — the same stack used by modern data teams.

Realistic industry databases with intentional messiness — NULLs, duplicates, refunds that settle after the sale, timestamps in inconsistent timezones. The things that eat analysts alive in the first week of a new job, baked in on purpose.

A 5-tier engine compares your result set against the expected answer and returns Slack-style graduated feedback — "directionally right but off by a filter," "right shape, wrong values," "fully correct" — not a binary pass/fail.

There's a free tier and a Pro tier. Free covers the Starter and Easy missions on every career path (10 per path) plus 12 coding interview questions — enough to learn the fundamentals. Pro ($14.99/month or $139/year) unlocks the Medium, Hard, and Expert missions, the full 40-question coding interview bank, and 71 advanced general interview questions. See /pricing for the full breakdown.

Every Medium, Hard, and Expert mission across all career paths; the full coding interview bank with questions tagged by real companies (Stripe, Meta, Amazon, and more); 71 advanced general interview questions across behavioral, statistics, A/B testing, product metrics, and case studies; and priority support.

Go to /account/billing and click “Manage in Stripe portal.” You can cancel, change plans, update your payment method, or download invoices from there. Cancellation takes effect at the end of your current billing period — you keep Pro access until then.

We don't offer partial-period refunds (Stripe doesn't pro-rate cancellations), but if you're unhappy with your first week of Pro email support@casesql.com and we'll sort it out.

Yes. Open the Stripe billing portal from /account/billing and pick the other plan — Stripe handles the proration automatically.

Any card that works with Stripe Checkout — Visa, Mastercard, Amex, Discover, and most regional cards. We don’t currently accept PayPal, bank transfer, or crypto.

Stripe sends every receipt and invoice directly to your billing email the moment the payment clears. You can also download every past invoice from the Stripe billing portal at /account/billing.

Each path has 30 missions (BI has 31, with the grain-reasoning capstone). A motivated learner can finish the free portion in a few evenings and the full Pro path in 2–4 weeks at a few missions per night. There’s no timer.

Yes, inside the coding interview bank — questions are tagged with the real companies they came from (Stripe, Meta, Amazon, and more). Career-path missions stay narrative and set inside simulated companies; the point of a path is to simulate the job, not the onsite.

Solo-built. See /about for the backstory, or send feedback to support@casesql.com.

The short version: more missions per path, more coding-interview questions, and better interview-prep UX. There\u2019s no public roadmap doc — the blog is where I write up what\u2019s shipped recently, and the feedback form is where you can nudge what\u2019s next. A lot of what gets built is driven by specific asks from users.

Email security@casesql.com with “Security report” in the subject. Please don\u2019t post details publicly (GitHub issues, Twitter, forum threads) before we\u2019ve had a chance to investigate. Valid reports get credited on request.

Your queries are yours. They\u2019re stored server-side so your mission progress, drafts, and XP persist across devices — nothing is sold, shared with third parties, or used to train models. The only people with read access are me (the founder) and Supabase (our database provider) in the normal course of keeping the service running. Full details on /privacy.