| T1 |
Hashing |
Modular arithmetic |
Consistent hashing; sharding |
ID generation; deduplication |
| T2 |
Trees |
Hierarchical sorted structure |
B-tree index; trie |
File systems; search prefix |
| T3 |
Graphs |
Edges and vertices; traversal |
Service dependency graph |
Social graph; routing; crawler |
| T4 |
Queues |
FIFO ordered processing |
Message queue; event stream |
Fan-out; async task processing |
| T5 |
Caching |
Store result, avoid recompute |
Redis; CDN; read-through cache |
Precomputed feeds; suggestion indexes |
| T6 |
Redundancy |
Copies protect against loss |
Database replication; RAID |
Multi-region; active-active |
| T7 |
State Machines |
States with transitions |
Event sourcing; CQRS |
Order lifecycle; trip state |
| T8 |
Divide & Conquer |
Split, solve, combine |
MapReduce; sharding |
Microservices decomposition |
| T9 |
Consensus |
Agreement under failure |
Raft; Paxos; quorum reads |
Distributed transactions; leader
election |
| T10 |
Encoding |
Represent information |
Serialisation; compression |
API versioning; data schema |
| T11 |
Feedback Loops |
Output feeds back to input |
Rate limiting; circuit breaker |
Surge pricing; A/B testing |
| T12 |
Tradeoffs |
Optimise under constraints |
CAP theorem; SLO design |
Build vs buy; roadmap decisions |