In search/social/IR: reputation graphs, PageRank, reachability, link canonicalization & dupe detection, identifying "objects" that are referred to by different

In search/social/IR: reputation graphs, PageRank, reachability, link canonicalization & dupe detection, identifying "objects" that are referred to by different names (eg. people, company names, knowledge graph, synonyms, etc.), propagating properties known to one entity onto related entities. In geo/rideshare/logistics: shortest-path routing, traffic flow, minimizing the distance driven by someone who needs to make multiple pickups, optimizing delivery routes. In health: contact tracing, recommending closures of social activities In industrial/EE applications: circuit theory, flow networks, load stresses In basic CS infrastructure: register allocation, dependency management, dead code removal, data-flow propagation, figuring out bandwidth requirements in a network