C
Memory, pointers, and the language the OS itself is written in.
What you'll actually learn
C doesn't hide memory from you the way almost every language you've probably used does — you allocate it, you're responsible for freeing it, and a pointer is genuinely just an address, not a metaphor. This track treats that as the point, not an obstacle: understanding C is understanding what every higher-level language is quietly doing on your behalf underneath, which is exactly why the OS itself, and most of the tools you already rely on, are written in it.
What you'll be able to do
You'll be able to read a segfault and actually reason about which pointer caused it instead of treating it as an opaque crash, and write code that manages its own memory correctly — allocating what it needs and freeing exactly that, no more, no less — which is the specific discipline that makes systems-level and embedded work possible.
Syllabus
Frequently asked
Roughly 1 hour across 6 hands-on quests — you can go at your own pace and pick up exactly where you left off.
You should be comfortable with Data & Applications, Algorithms & Data Structures first — the skill tree unlocks C once you've cleared those.
Yes — C is fully available on the free tier, starting with a free first quest and no payment method required to sign up. Plus and Elite remove pacing limits but don't gate any of the C curriculum behind a paywall.
Create a free account and begin your first quest — no card required.
Start free