Brilliant: Learn by doing positions itself as an educational platform focused on developing quantitative reasoning through hands-on problem solving. Unlike traditional lecture-based learning systems, the app emphasizes active participation with interactive visualizations and progressively challenging puzzles. The content spans foundational mathematics, computer science fundamentals, and scientific thinking, targeting both students and professionals seeking to sharpen their analytical abilities. The core functionality revolves around daily challenges and structured courses that build concepts incrementally. Each lesson begins with intuitive visual explanations before introducing interactive elements where users manipulate variables or arrange logical sequences. The computer science track, for instance, guides learners through algorithmic thinking with drag-and-drop coding exercises rather than syntax memorization. Physics courses incorporate simulated experiments where adjusting parameters demonstrates cause-and-effect relationships in real time. In practical use, the app proves particularly valuable during short learning sessions, with many courses designed for 5-15 minute daily commitments. The interface maintains clean visual design with minimal distractions, though some users note the navigation between related concepts could be more fluid. The progressive difficulty curve means beginners can start with basic logic puzzles while advanced learners tackle probability trees or quantum mechanics visualizations. Offline functionality remains limited to downloaded content only, which may disappoint commuters with inconsistent connectivity. User feedback consistently highlights the app's effectiveness for developing problem-solving intuition. Reviews indicate the visual approach helps cement understanding of abstract mathematical concepts that often remain opaque in textbook explanations. One user noted spending '30 minutes daily during commute instead of mindless scrolling' resulted in noticeable improvement in analytical thinking at work. However, some advanced learners express desire for more specialized content beyond the current intermediate-level offerings. Overall assessment finds Brilliant succeeds most as a supplementary learning tool rather than comprehensive curriculum replacement. The interactive methodology genuinely enhances conceptual understanding, particularly for visual learners, though the subscription model may deter casual users. The app's strongest value emerges in its ability to make complex quantitative topics engaging and accessible without oversimplifying the underlying principles.