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Data Structures & AlgorithmsComplexity analysis up to graphs and DP.Operating SystemsProcesses, scheduling, memory and concurrency.Database Management SystemsRelational modelling, transactions and indexing.Computer NetworksFrom wires and radio waves up to the web.

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Operating Systems

Foundations of Operating Systems3

Processes & Threads4

Inter-Process Communication3

Concurrency & Synchronization4

CPU Scheduling4

I/O & Disk Scheduling3

Memory Management4

Virtual Memory3

What a file actually is, and how directories find them
File allocation methods — where a file's actual bytes live on disk
Tracking free space, and surviving a sudden power loss
Putting it all together — the full journey of writing a file

Building Your Own OS in C++6

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Operating Systems

Foundations of Operating Systems3

Processes & Threads4

Inter-Process Communication3

Concurrency & Synchronization4

CPU Scheduling4

I/O & Disk Scheduling3

Memory Management4

Virtual Memory3

What a file actually is, and how directories find them
File allocation methods — where a file's actual bytes live on disk
Tracking free space, and surviving a sudden power loss
Putting it all together — the full journey of writing a file

Building Your Own OS in C++6

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Tracking free space, and surviving a sudden power loss

How the file system knows which blocks are actually free, and the clever logging trick that keeps your files intact even if the power dies mid-write.

9 min readUpdated 2026-09-03operating-systemsfile-systemsjournalingfree-space-management