Designing Offline-First CBT Practice for Unreliable Networks A computer-based test product is often designed as if connectivity were a permanent dependency. That assumption breaks quickly for learners who share devices, pay for data in small amounts, or study in places where a connection disappears without warning. Offline-first design changes the question from “How do we keep the learner online?” to “Which parts of the learning loop must remain useful when the network is unavailable?” ...