This sounds like an amazing resource. What’s the rationale for making it all free?
The writing is on the wall for Leetcode-style interviewing. The signal-to-noise ratio is diminishing in the age of AI (cheating). These sorts of puzzle challenges might no longer play a meaningful role going forward.
What is hopefully dying is companies asking verbatim LeetCode questions and candidates having to memorize a bunch of questions. We wrote this book largely because we wanted to teach people how to think. I knowing how to think is only going to get more valuable.
It’s FAR easier for companies to stick with the interview process they’ve used for decades—just mandate in-person interviews again—than to reinvent the wheel with some new, unproven format. Sure, there’s a growing need to assess more than just DS&A in initial screenings, but let’s be honest: those interviews aren’t going anywhere.
The REAL reason to make these resources free? Because it’s not a competitive advantage to offer problems to practice. There are already tons of free problems online. The real value isn’t in giving people a place to do problems—that already exists. The value is in the book. If you already know enough to do well on problems without the book, then you shouldn't have to pay to practice it.
I bet the genuine answer to your question is that she knows it's a resource that could help tons of people (at a time when tons of people need that help) and paywalling it means that it won't serve that same purpose.