Quantercise started as my own quant interview prep tool and turned into a full product: 400+ problems, real-time Python execution, math rendering, progress tracking, and payments.
quantercise
a place to practice quant problems, work on mental math, and write Python
under the hood
Product Stack
Next.js and React power the practice interface, Postgres and Drizzle hold the problem system, and isolated serverless execution grades Python submissions.
Problem Engine
Problems support 5 answer types. Numeric with tolerance, exact string matching, single-choice MCQ, multi-choice MCQ, and Python coding challenges. Answer specifications are stored server-side only to prevent cheating. The grading system runs entirely on Lambda with isolated execution contexts.
Editor and Math Rendering
Monaco Editor powers the Python coding experience with syntax highlighting and autocomplete. KaTeX handles mathematical notation rendering across all problems. Both integrate cleanly with the Next.js App Router through client components.
Gamification
Points system awards 10/20/30 for easy/medium/hard problems with first-attempt bonuses. Daily streak tracking with 24-hour grace period. Leaderboards support daily, weekly, and all-time periods. User stats track progress by difficulty level.