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Operating Systems

Learn about processes, threads, memory management, scheduling, and kernel internals.

Many of the hardest bugs—deadlocks, stalls, OOMs, and unpredictable latency—are symptoms of deeper operating system behavior. They arise from scheduling decisions, memory management, and I/O coordination, not just code paths.

The topics below focus on building an accurate mental model of processes, threads, virtual memory, and kernel boundaries, enabling you to reason about performance and failure under real-world constraints—and articulate those interactions clearly when it matters most.

Topics in this category

OS Architecture (Monolithic vs Microkernel)

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Compare monolithic and microkernel operating system architectures and their trade-offs.

Medium9 min

Process vs Thread

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Understand the fundamental differences between processes and threads: isolation, memory sharing, context switching, and when to use each.

Beginner10 min

Context Switching: Concepts, Internals & Interview Use Cases

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Understand how the OS switches between processes: saving and restoring CPU state, PCB (Process Control Block), and performance implications.

Medium10 min

PCB (Process Control Block)

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Learn Process Control Block structure that stores process state and context information for process management and context switching.

Medium9 min

Scheduling Algorithms (RR, FCFS, SJF, Priority)

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Master CPU scheduling algorithms: Round Robin (RR), First Come First Served (FCFS), Shortest Job First (SJF), and Priority scheduling. Understand their characte

Medium13 min

Memory Management: Concepts, Internals & Interview Use Cases

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Learn how operating systems manage memory: allocation, deallocation, protection, virtual memory, and memory hierarchy.

Medium12 min

Virtual Memory: Concepts, Internals & Interview Use Cases

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Understand virtual memory: how operating systems provide larger address space than physical memory using paging, swapping, and address translation.

Medium11 min

Paging & Segmentation

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Master memory management techniques: paging (fixed-size) and segmentation (variable-size), their advantages, disadvantages, and when to use each.

Medium11 min

Page Faults & Page Replacement Algorithms

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Learn page faults and replacement algorithms: LRU, FIFO, Optimal for virtual memory management and efficient page swapping.

Medium11 min

Caching in OS (L1/L2/L3)

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Understand CPU cache hierarchy: L1, L2, L3 caches and cache coherence.

Medium8 min

Synchronization (Mutex, Semaphore)

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Learn synchronization primitives: mutexes and semaphores for thread synchronization, preventing race conditions, and coordinating access to shared resources.

Medium11 min

Deadlock (Conditions, Prevention)

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Understand deadlock conditions (mutual exclusion, hold and wait, no preemption, circular wait) and prevention strategies.

Medium11 min

Shared Memory vs Message Passing

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Compare inter-process communication: shared memory (fast) vs message passing (safe).

Medium8 min

System Calls: Concepts, Internals & Interview Use Cases

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Understand system calls: interface between user programs and the operating system kernel. Learn how programs request OS services, the overhead involved, and com

Medium8 min

Kernel Mode vs User Mode

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Learn CPU privilege levels: kernel mode (privileged) vs user mode (restricted) for security.

Medium8 min

Interrupts & Traps

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Understand interrupts (hardware events) and traps (software exceptions) in operating systems.

Medium8 min

Signals: Concepts, Internals & Interview Use Cases

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Learn Unix signals: software interrupts for inter-process communication and control.

Medium7 min

I/O Management: Concepts, Internals & Interview Use Cases

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Learn I/O management: device drivers, I/O scheduling, and interrupt handling.

Medium8 min

DMA (Direct Memory Access)

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Learn DMA: allows devices to access memory directly without CPU intervention.

Medium7 min

Disk Scheduling (SCAN, C-SCAN)

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Master disk scheduling algorithms: SCAN, C-SCAN, FCFS, SSTF for optimizing disk I/O.

Medium8 min

File Systems (EXT4, NTFS, FAT32)

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Compare file systems: EXT4 (Linux), NTFS (Windows), FAT32 and their characteristics, features, and use cases.

Medium10 min

Inodes: Concepts, Internals & Interview Use Cases

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Learn inodes: data structures that store file metadata in Unix/Linux file systems.

Medium8 min

Networking Stack in OS (Socket APIs)

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Understand the networking stack in OS: socket APIs, TCP/IP implementation, and network layers.

Medium9 min

Threads Models (1:1, N:1, M:N)

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Compare thread models: 1:1 (kernel threads), N:1 (user threads), M:N (hybrid).

Medium8 min

Containers vs VMs (Namespaces, Cgroups)

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Compare containers and VMs: namespaces, cgroups, and virtualization technologies. Understand isolation, resource management, and when to use each.

Medium11 min

Boot Process: Concepts, Internals & Interview Use Cases

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Understand the operating system boot process: BIOS/UEFI, bootloader, kernel initialization.

Beginner8 min

Shell vs Kernel

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Understand the difference between shell (user interface) and kernel (core OS).

Beginner7 min

Linux Basic Commands

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Learn essential Linux commands: file operations, process management, networking, and system info.

Beginner8 min