Migrated a 3,400-line Visualforce page to Lightning Web Components without rebuilding it.
A 5-year-old Visualforce page handled 80% of daily interactions and had grown to 3,400 unmaintainable lines. The codebase had grown too tangled to safely touch — every change carried real risk.
I refused the rebuild. The data model was sound — only the UI was choking. Decomposed the page into discrete LWC components and migrated them section by section over 8 weeks, keeping the Visualforce shell live until each piece was proven in production.
6.2s → 0.9sFirst contentful paint dropped from 6.2 seconds to under 1 second. The codebase shipped with a component library the in-house dev can extend independently. Total cost: a quarter of the original quote.