CrackingWalnuts
More than interview prep. Your path forks at Senior, into building (IC) or leading (management). Pick a goal, see the real bar, and follow the exact path to get there.
Built by Staff Engineers, Principal Engineers, and Engineering Leaders who've built systems, led teams, and hired engineers.
The bar for each level is the real one, not generic advice.
Live now
Caches is free. The rest go live before the end of this month.
Open CompareRead in order
One a week from next month
A playbook is the forty-minute answer. A deep dive is the whole design behind it, with the numbers. The missing ones start next month, one a week.
Read the deep divesQuestion: You upgrade from 1 Gbps to 10 Gbps. The same transfer takes just as long. What is the limit?
Have your answer in mind, then reveal.
Pick a level and be honest. Could you actually answer each of these out loud, right now? If several are shaky, that is the gap, and that is exactly what the path is for.
The bar: Design across services, make and defend trade-offs, and lead a design review.
If several are shaky, you are probably not there yet. Here is the path.
See the Senior Engineer pathWhether you are building LLM systems or getting grilled on them, go deep: the foundations, the engineering, the security, and the AI system design round. Read a full lesson free before you decide.
When we started Cracking Walnuts, it was free and pretty small. It isn’t small anymore.
Engineers from almost every country use it now, and honestly, we never imagined it would reach this many people. We want to keep building it for years, not months, and keeping everything free doesn’t let us do that. So we’re moving to a membership.
One membership. Every track, every tool, every new feature. Everything you need to grow from interview preparation to senior engineering and leadership.
Every topic gets real engineering behind it: code you can run, tools you can play with, and diagrams built to make the idea click. We keep it all current as the field moves, when frameworks evolve, system internals change, or interview expectations shift. You’re joining a platform that keeps getting better, not one that’s published once and left behind.
As a member you get everything available today, plus everything we build while you’re with us. We’re keeping a good part of the site free too, so you can decide it’s worth it before subscribing.
If it helps you become a better engineer, it pays for itself.
We’ve got a lot planned, and we’re excited for what’s ahead.
One payment for 12 months. No auto-renewal.
One yearly plan. No auto-renew.
Nine code quality numbers, each worked out by hand on one JavaScript function and then checked against the tool. Coverage is only the first of them.
Now we also crack a few walnuts out loud, on video. Everything here stays right where it is.