---
title: "Senior Software Developer"
author: "Jarrod Carlson"
company: "DealerMatch"
industry: "Automotive remarketing"
location: "Atlanta, GA"
period: "Mar 2013 – Jun 2014"
tech:
  - "Ruby on Rails"
  - "JavaScript"
  - "Spine.js"
canonical: "https://builtbyjarrod.com/experience/dealermatch"
---

# Senior Software Developer — DealerMatch

Mar 2013 – Jun 2014 · Atlanta, GA

> Dealer-to-dealer automotive marketplace startup, wholly owned by Cox Automotive, Inc.

**Summary:** Became the de facto technical voice on a 20-developer, full-time-pairing team, hardening a consultant-built single-page-app prototype into a production marketplace where dealers traded millions of vehicles — and skipped the auction.

---

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](/experience/manheim.md) — and again at
[Cox in 2018](/experience/cox-automotive.md).