Below the Code
OS & Networks
The systems layer of computer science — how one machine runs your program (processes, memory, scheduling) and how millions of machines talk to each other (TCP/IP, HTTP, DNS). The knowledge every other track quietly depends on.
2Pillars building
16+Topics planned
2Coming soon
100%Interview-relevant
Four pillars
OS and Networking roadmaps are live now and filling with full guides. Security and Theory follow.
Roadmap live
Operating Systems
What actually happens when you run a program — processes vs threads, virtual memory, CPU scheduling, filesystems, and the concurrency bugs interviewers love.
View roadmap →
Roadmap live
Networking
What happens when you type a URL — the TCP/IP stack, HTTP/S, DNS resolution, sockets, and the handshakes underneath every request your apps make.
View roadmap →
Coming soon
Security
Authentication vs authorization, hashing and TLS, the OWASP top 10, and how real attacks work — the layer every production system needs.
In the works
Coming soon
Theory of Computation
Finite automata, regular expressions under the hood, Turing machines, and P vs NP — why some problems are hard no matter the hardware.
In the works
Why this section exists
01System design assumes it — you can't reason about load balancers without TCP, or containers without processes.
02Interviews probe it — "what happens when you type a URL" and "process vs thread" are evergreen questions.
03Debugging lives here — memory leaks, port conflicts, DNS failures: the systems layer is where prod issues hide.