B&J — what was hard (for the "what surprised us" section)
[Our observation] throughout this section.
The regulatory layer is intricate and Ontario-specific. O. Reg. 217/01 vs O. Reg. 213/01 is the most-confused operational question in customer conversations. Coloured fuel under Ontario's Fuel Tax Act. TSSA Mobile Fueling Licence requirements. The 2025 propane tax changes. The April 2026 federal excise suspension. All of this had to be researched primary-source (not Wikipedia, not industry blog posts) before it could be written into copy.
The lubricants OEM crosswalk. Petro-Canada Lubricants publishes a handbook with 269 products and 95 OEM specs across John Deere, Case IH, Massey, Volvo, Mack, Cummins, Allison, etc. Translating that into a customer-facing decision tool with named approval-status labels required parsing the handbook, reconciling sub-brands, and ingesting product images — three separate Claude Code sessions to get right.
The Davis & McCauley transition. B&J recently acquired Davis & McCauley Fuels in London. The digital transition is delicate: kill the brand too fast and you lose D&M's existing search equity; keep it too long and you fragment B&J's brand. The transition page strategy (the audit's "single most important architectural decision") puts D&M's existing URLs through a content-driven landing page rather than a hard redirect to B&J's homepage.
Source-attribution density. Every page that surfaces a tax rate, a regulatory citation, or a program status needs a tooltip and a sources footer. This is visually heavy and required design discipline to keep readable.
The state-machine for programs. OSCIA intake windows open and close; iMHZEV ended; the federal carbon charge went to zero but invoices still showed it through Q1 2025; the federal excise suspension is time-bounded. Modeling "what's currently in effect" with stale-data behavior visible to the user was nontrivial.