Modern systems are full of graph-shaped problems: roads, services, users, jobs, dependencies, and network flows. Graph algorithms help systems reason about reachability, order, cost, and centrality.
Why it shows up
Choose it when you care about connectivity, path cost, ordering constraints, or influence across a network.
Common domains
Road networks, flights, and logistics paths
Mapping systems model locations as nodes and roads or flights as edges, then compute low-cost routes using shortest-path methods.
Why this structure fits
The real problem is connectivity plus weighted path cost.
Dependency graphs and execution order
Compilers, CI pipelines, and schedulers must know what can run now and what depends on what.
Why this structure fits
Topological reasoning turns dependency constraints into a valid execution order.
Accounts, devices, transactions, and communities
Risk systems inspect clusters, shared endpoints, and suspicious paths across connected entities.
Why this structure fits
Patterns of relationships often reveal more than isolated records.
Service calls, ownership links, and failure blast radius
Operational tooling models service-to-service dependencies to understand propagation and incident impact.
Why this structure fits
Service interactions form a graph, not a flat list.
