Data structures in production

Topics that show up in real systems, not just coding rounds

Click a topic to see where it appears in operating systems, databases, editors, recommendation systems, search, compilers, and large backend services.

Topics

Focus

Real-world applications

Examples

Kernels, DB indexes, schedulers

4 examples

Linked List

Pointer rewiring inside kernels, caches, and allocators

Linked lists are useful when a system needs cheap insertions and removals after it already holds a pointer to the node.

OS kernelsmemory allocatorsLRU caches

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4 examples

Dynamic Programming

Used when optimal answers are built from smaller overlapping states

Dynamic programming appears in systems that need optimal or near-optimal decisions over many repeated subproblems.

route planningsequence analysisresource scheduling

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4 examples

B-Tree

The data structure behind many database and storage indexes

B-Trees keep large ordered datasets shallow, making them ideal for disk-backed and page-oriented storage.

database indexesfilesystemsstorage engines

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4 examples

Binary Tree

Tree-shaped reasoning in compilers, compression, and decision systems

Binary trees appear when a problem naturally branches into left and right choices or when hierarchical evaluation is required.

expression parsingcompressiondecision systems

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4 examples

Graphs

Relationships, networks, routes, and dependencies

Graphs are the right model whenever the important thing is how entities connect, not where they sit in memory.

mapsservice topologysocial networks

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Hash Table

Fast lookup for caches, symbol tables, and session state

Hash tables are everywhere because many production systems need near-constant-time lookup by key.

cachescompiler symbol tablessession stores

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Heap

Priority-first access for schedulers and ranking systems

A heap is the standard structure when the next item you need is the smallest or largest according to some priority.

task schedulerstop-k rankingshortest path search

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TRI

4 examples

Trie

Prefix-aware search for autocomplete, routing, and dictionaries

A trie is useful when the prefix of a string is as important as the full string itself.

autocompleterouting prefixesIDE search

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Greedy Algorithms

Local decisions that are good enough because the structure allows it

Greedy algorithms are common in scheduling, compression, and networking when a carefully chosen local rule leads to a globally good result.

job schedulingcompressionnetwork optimization

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