Senior Software Developer

Taking a used car to auction means transporting it twice — seller to auction, auction to buyer — and settling for an auction price. DealerMatch, a startup wholly owned by Cox Automotive, offered dealers a way out: list your inventory directly to other dealers, field offers and counters until the price is right, and cut the transport in half — all for a flat monthly subscription instead of auction fees. It was a slightly heretical idea for the owner of the world’s largest auto auction to fund, and they ran it like a real startup: about 125 people at peak, with genuine autonomy from the Cox enterprise world, down to making our own tech stack decisions. This was my first tour with a Cox company.

Millions of vehicles, one VIN at a time

An accurate listing starts with the VIN — from that alone you can decode most of what a vehicle is. The platform combined VIN decoding with dealer inventory feeds, and here the Cox connection paid off: most dealerships already managed their inventory on another Cox Automotive product, so when a dealer signed up, we already knew what was on their lot and could have their listings ready. At any given moment the platform carried millions of listed vehicles, plus the constant churn of bids, offers, and counteroffers moving between dealers.

Operationalizing the prototype

The original stack was laid down by ThoughtWorks consultants with progressive tastes: a JavaScript single-page application on Spine.js — search results, vehicle details, offer negotiation, and post-sale flows — backed by Rails, in 2013, when SPA frameworks were dime-a-dozen and none of them mature. By the time I arrived, the job was turning fast proofs of concept into a production business: hardening the database layer for performance, ironing out UI/UX frontier problems like making the browser’s back button behave in a stateful app, and getting 20 engineers to agree on how to do Rails — fat models or Java-style service objects? (There were… differing opinions.)

We worked in full-time pair programming, rotating pairs daily. I wasn’t formally a lead, but my technical judgment became quickly recognized — this is where I found my voice for steering teams toward decisions justified by something better than “sounds neat,” and the head product owner leaned on me regularly for ad-hoc analysis of what the data could and couldn’t support.

A new paradigm

DealerMatch rewired how I think about front ends. Every site I’d built before was round-trip, whole-page rendering; an SPA is a stateful application living in the browser, where everything you took for granted — even the back button — means something new. Succeeding at it meant thinking like an application developer, not a classic web developer, and that mindset never left me.

I left in June 2014, and Cox announced DealerMatch’s retirement barely a month later — I’d read the signs as investment shifted from technology growth to pure feature velocity. The people outlasted the product: many of the engineers moved on into Cox Automotive proper, including the enterprise architect and dev-ops engineer I’d work with again at Manheim — and again at Cox in 2018.