System Design Arcade

Jul 9, 2026

Jump straight into a level on first launch — no setup, no sign-up wall.

• Fixed: signing in with a different account could inherit the previous account's score and leaderboard spot.
• Fixed: progress could be lost when a sync failed.
• A full correctness pass over all 48 games — ~300 fixes to explanations and answers.
• 62 new "why" challenges that test your reasoning, not just recall.
• Architecture challenges now accept equally-valid designs.