Most SAT prep apps give you a static question bank. You grind through the same pool, eventually memorizing answers instead of learning concepts. The questions never change, never adapt, never get smarter.
PrepSAT is different. Our question bank is a living system that evolves based on how students answer. Questions get harder where you're strong, break into sub-skills where you struggle, and grow in complexity over time.
Inspired by Karpathy's Autoresearch
In March 2026, AI researcher Andrej Karpathy open-sourced a project called autoresearch. The idea was simple but powerful: let an AI agent run experiments in a loop, measure results, keep what works, discard what doesn't, and repeat. Overnight, the system ran hundreds of experiments and progressively improved its own neural network training code.
We asked: what if we applied that same recursive loop to SAT questions?
How Question Evolution Works
Every question in PrepSAT has DNA: difficulty level, concept tags, reasoning steps, and a complexity score. When you answer a question correctly, the system can generate evolved variants that push you further.
A Simple Example
Say you nail a basic trigonometry question: "If sin(x) = 0.5, what is x?" That's a one-step recall question. The evolution engine might generate:
- Generation 1: "If sin(x) = 0.5 and 0 < x < pi, find the two possible values of cos(x)." (adds a constraint, requires identity knowledge)
- Generation 2: "If 33 sin(x) > 23 cos(y), what is the minimum value of tan(x)?" (combines trig with inequality and optimization)
Each generation adds a layer: an extra constraint, a concept combination, an optimization step, or a trap answer. The questions that survive validation get tagged with their lineage and added to the bank.
Validation: No Bad Questions
Every evolved question goes through automatic validation before it enters the bank. The AI solves each question step-by-step to verify the answer is correct, the math is sound, and the difficulty is appropriate. Questions that fail validation get discarded.
This means you'll never encounter a broken question or an incorrect answer. The evolution engine is aggressive about generating new variants, but conservative about what it actually serves to students.
What This Means for Your Score
Static question banks plateau. Once you've seen the types, your score stops climbing. PrepSAT's evolving bank means you always face questions at your growth edge. Not too easy (boring), not too hard (demoralizing), but right at the boundary of what you can do, pushing you forward with every session.
That's the recursive loop in action: test, learn, evolve, repeat. Each cycle makes both you and the system smarter.