#5. TCP Deep Dive - Reliability vs Latency
The One Thing to Remember
TCP trades latency for reliability. Every feature of TCP—the three-way handshake, acknowledgments, retransmissions—adds
#4. CPU Scheduling & Context Switches - Throughput vs Latency
The One Thing to Remember
Context switches are expensive; minimize them. Every time the CPU switches between tasks, it must
#3. File I/O & Durability - Why fsync() Is Your Best Friend (And Worst Enemy)
The One Thing to Remember
fsync() is your durability guarantee. Without it, your "written" data might just be
#2. Memory Management Demystified - Virtual Memory, Page Faults & Performance
The One Thing to Remember
Virtual memory creates the illusion of infinite RAM. Every process thinks it has the entire
#1. Process vs Thread - The Foundation Every Backend Engineer Must Know
The One Thing to Remember
Process = house, Thread = room in the house.
But here's why you actually care:
