Six and a half years on a dealer platform, and the parts I put my name on

Tadvantage is the WordPress multisite platform behind Convertus dealer websites. It has ten OEM and dealer-group themes and more than thirty-five custom plugins for inventory, showroom, pricing, SEO, integrations and analytics, with Vue on the interactive parts and PHP underneath. Convertus is part of Trader Corporation, the company behind AutoTrader.ca.

Of the more than a hundred engineers in the codebase’s history, I was the top contributor of all time: 1,682 commits and 358 merged pull requests. Along the way: 253 tickets, 177 release commits and 39 hotfixes. The count starts in January 2019, not my start date, because my first couple of months went in under a colleague’s pull requests. I owned production releases from v3 through v12.7 and merged the French translations for most of them.

A price shows up in more places than you’d expect: four versions of the search-result card, the vehicle detail page, the quick view, the inventory carousel, and a calculator with cash, finance and lease tabs. If any two disagree, the shopper stops trusting the number and the dealer carries the compliance risk. I built Canada’s federal luxury tax into all of them, behind a feature flag so we could roll it out dealer by dealer.

AutoTrader.ca IQ Badging marks a vehicle as a Good Price or Great Price against the market, in search results and on the vehicle detail page. I integrated the newly available AutoTrader data behind it, then built the badge once as a Vue component. The same badge, from the same data, shows on every vehicle card the platform draws, wherever it appears on the site and whatever component it sits in. I also added WordPress options to configure it.

I created the object-caching repository and moved the platform to Object Cache Pro, with a dedicated Redis host in production and shared clusters in dev and staging. I proved it out on a separate test network before it shipped. It ended three years of the cache being added and reverted, and nobody reverted it in the three years after; the AutoTrader.ca page tells that story in full. Later I rolled page caching out to the whole fleet with WP-CLI. It skips the inventory and showroom routes, which can never be served stale, and it’s wired into the deploy scripts so every new site gets it without anyone setting it up.

The partner integrations I worked on:

CARFAX v3

Auth0 token generation

Ford

Model E inventory and OEM window stickers

Motocommerce

Build-and-price, with deep links that carry colour and trim

Honda, Lincoln, Jeep

Showroom mapping

Hyundai

Roadster

Shift Digital, CarGurus

Dealer data feeds over SFTP

I built the SEO foundation: inventory sitemaps in English and French, Product and Breadcrumb schema with the VIN as the identifier, and canonical handling across the detail page, the search page and the print view. I also maintained a fork of Yoast that carried inventory sitemap support through three major versions. And I built the Bill S-211 compliance pages, which publish themselves to every dealer site in both languages, so no one has to remember to set them up.

The platform polled for inventory changes; webhooks would have been more accurate and less wasteful. Some jQuery stayed in for legacy integrations instead of being migrated. That shipped faster, and it left debt behind.

Most of all, I’d instrument it from day one. Nobody measured save, remove and compare events, so this case study has no adoption figures; the data was never collected. Next time I’d decide how we’ll know a feature worked before we ship it.