Signals,systems&
thedeepcode.
Long-form engineering write-ups on how modern systems actually work. Articles, interactive browser-based labs, quick recall quizzes, and a dedicated systems atlas.
What's inside
Every article ships with an interactive lab and a quiz.
Networking
TCP, DNS, BGP, QUIC, and the protocols that hold the internet together.
Operating Systems
Scheduling, virtual memory, containers, and the kernel underneath.
Security
TLS, cryptography, password hashing, and how systems get broken.
Databases
Write-ahead logging, crash recovery, storage engines, and consistency.
Hardware
CPU pipelines, DRAM internals, SSDs, and low-level silicon.
Signals & RF
GPS, radar, software-defined radio, and wireless from the physics up.
Latest
How the Dewey Decimal System Actually Works
DDC structure, call number synthesis, shelf ordering, Linux automation, and why Dewey still works well in public libraries but not every collection.
How Supply Chain Signing Actually Works
Supply chain signing is not a badge on a package. It is a chain of digest, identity, transparency, provenance, and policy around specific bytes.
How DDoS Mitigation Actually Works
A deep dive into DDoS mitigation: attack shapes, anycast, scrubbing, SYN cookies, origin shielding, and the tradeoffs behind keeping systems reachable.