Reducing a 66-node dependency cycle to 13 in Scrapy

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I built PViz to help developers understand the structural shape of large codebases — surfacing module coupling, strongly connected components, and the edges driving them.To put it through its paces, I ran it on Scrapy with a concrete goal: reduce SCCs without changing runtime behavior.Starting point → Final result: - Largest conceptual (TYPE_CHECKING-masked) SCC: 66 → 15 nodes - Runtime SCC: 23 → 2 nodesGoing in with no prior knowledge of the codebase, the refactor took 68 iterations and surfaced some non-obvious structural behaviors:- Runtime coupling collapsed early (23 → 4 by iteration 17) while the conceptual graph stayed largely intact — suggesting runtime and conceptual coupling respon

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Website: pvizgenerator.com/showcase/2026-04-scrapy-scc-refactor