Everything you wanted to ask before signing up.

Software engineers preparing for FAANG, Staff+, or principal-level system design interviews. If you can already write production code but get stuck drawing the whiteboard under pressure, you're our target learner.

You should be comfortable as a working software engineer — familiar with databases, APIs, and at least one backend. You don't need to already know sharding, quorum, or CRDTs. The graph teaches those from the prerequisites up.

For most users, 3–6 months at ~30 min/day gets you from a cold start to interview-ready on the core FAANG design rubric. Users with strong priors finish sooner; users with no backend ops exposure take longer. The dashboard tells you where you are — you don't have to guess.

Not really. LeetCode is a library — here are 3,000 problems, pick one. DesignGraph is a tutor — it picks the exact next problem for you, grades your answer, and decides what to queue up tomorrow. The library is means, not end.

The core graph today is senior/staff distributed-systems design — the kind of round you get at FAANG and FAANG-adjacent companies. Low-level and machine-coding rounds are on the roadmap but not live yet.

The web app works on phones for review and short drills. For the longer design drills — the ones where you're writing trade-offs and sketching flows — you'll want a laptop.

$9 per month, or $90 per year (two months free). No hidden tiers, no per-feature upsells, no ads.

We do a 7-day money-back guarantee instead of a free trial. Subscribe, use everything without restrictions for a week, and if it didn't move the needle we'll refund you — no back-and-forth.

Yes, from the dashboard. Cancel ends your subscription at the next billing period. Pause freezes your spaced-review queue — useful if you're on vacation or between job hunts.

Not yet. Try it as an individual first; once you've tried it, reach out via support and we'll work something out if your company wants to sponsor it.

All major credit/debit cards via Stripe. No PayPal, no crypto, no local bank transfer at this stage.

Courses optimize for coverage ("we taught everything") at the expense of retention. Mastery-based learning refuses to let you advance past a concept you haven't actually internalized. The result: what you learn, you keep.

The graph tracks when you last demonstrated each concept. Concepts you've just learned resurface quickly; concepts you've nailed multiple times come back at longer intervals. By the time interview day arrives, nothing in the graph has had time to fade.

Each drill has a canonical answer and a grading rubric that lists the specific properties your response has to satisfy. Your answer gets scored against that rubric, and you get feedback pointing at the specific gaps — the way a Staff engineer would read your whiteboard.

It can be, especially on judgment-call trade-offs. When you disagree, you can flag a grade — every flag goes into a review queue where we tighten the rubric. Over time, disagreements become rarer as the rubrics get sharper.

Because 30 focused minutes of calibrated practice crushes 2 hours of passive reading. Short sessions are easier to commit to, keep your recall active between days, and fit into an actual working life. You can do more than one session if you want — diminishing returns kick in faster than you'd think.