Invest in your data career

LDS is built to be the all-in-one platform for data science professionals. You get SQL and Python practice, step-by-step query and code visualization, interactive courses, interview recall cards, curated industry news, and in-depth articles — all in one place. Our premium problems span 15 industry domains like AdTech, FinTech, Healthcare, Banking, etc., each with production-grade schemas that mirror how data teams operate at top companies. No other platform combines hands-on coding, visual execution walkthroughs for both SQL and Python, and learning resources under one roof.

Our first 1,000 paid subscribers lock in Pro access at a dramatically reduced founding price for their first 12 months. Monthly: $3.99/mo (₹349/mo). Annual: $29.99/yr (₹2,599/yr). After the founding period, your subscription transitions to regular pricing — monthly: $9.99/mo (₹849/mo), annual: $79.99/yr (₹6,999/yr). This is our way of rewarding early supporters.

Absolutely. Cancel anytime from your account settings. No questions asked. You keep access until the end of your billing period.

After 12 months, your subscription automatically transitions to regular Pro pricing. You'll be notified well before the change. You can cancel anytime before or after the transition.

Our signature feature that brings your code to life. For SQL, it shows exactly how your query processes data step-by-step — joins, filters, aggregations, window functions — all rendered as interactive diagrams. For Python, it breaks down your pandas pipeline operation by operation so you can see how each transformation shapes the data. Free users get 5 visualizations per day; Pro members get unlimited access.

Pro unlocks 15 specialized domains: AdTech, Banking, FinTech Trading, Healthcare Claims, Lodging, Logistics, Food Delivery, Ride-Hailing, Payments, Real Estate, Retail, SaaS B2B, Social Graph, Streaming Media, and Telecom. Each domain has its own production-grade schema with realistic data that mirrors how companies like Stripe, Uber, Netflix, Google, Airbnb, Meta, etc. structure their data — so you practice with the same patterns you'll encounter on the job.

We accept all major international credit and debit cards (Visa, Mastercard, Amex) via Razorpay. Prices are displayed in USD and INR.

Yes, completely free — no credit card required. You get 126 SQL questions, 124 Python questions, 5 visualizations per day, full access to interactive courses, Quick Recall interview cards, news, and blog articles. Upgrade to Pro only when you want access to 1,500+ questions across 15 industry domains, unlimited visualizations, and unlimited audio content.