The career pivot with a stubborn coach.

Wei was a five-year PM trying to pivot into ML. He'd finished three MOOCs. He could not, on demand, explain how gradient descent worked or when to use L2 versus L1 regularization.

He started using Brainback as the accountability layer around his existing course material. Watch a lecture, then attempt problems in Learn mode. Explain the concept back at the end of every session. Recall queue for the week.

Six months later he landed a data science role at a mid-sized fintech. During his final interview, he was asked to explain the bias-variance tradeoff. He did. He got the offer that afternoon.