Senior Full-Stack Engineer for Complex SaaS Systems

Senior full-stack engineer with 12+ years across CRM, ad tech, QA automation, integrations, and legacy modernization. Strongest in frontend-led product engineering, cross-system debugging, and translating messy business workflows into stable production software.

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David Justice with his dog

About

I've always been drawn to systems — how they connect, where they break, and how to make them work better. I started in tech support, moved into QA and automation, and eventually into engineering because I wanted to understand the systems I was testing deeply enough to fix them myself. That path shaped how I work: I care about maintainability, reliability, and the real-world behavior of software under pressure. I'm frontend-minded but comfortable across APIs, databases, and search layers. Lately I've been building AI-assisted workflows with Claude and MCP that have meaningfully changed how my team plans and ships. Long term, I'm interested in roles closer to the intersection of engineering, product, and system design — senior engineering, TPM, or solutions engineer at a B2B SaaS company where the work actually matters.

Selected Impact

Featured Work

Internal Google Ads Platform

Served as the sole frontend engineer for an internal campaign platform used by a 34-person digital marketing team managing 3,000+ client accounts and $784K+ in ad spend. Shaped early architecture in React/MUI and built automated budget management, in-app controls, and CRM integrations.

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Modernizing a Legacy CRM Contact Experience

Led redesign and refactor work across contact pages, filtering, and action systems — including a Vue 2 to Composition API migration — while preserving permissions, communication states, and business-critical legacy behavior.

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Fixing Search and Data Access Parity

Reconciled SQL and Elasticsearch query behavior so segmentation, permissions, and contact visibility matched intended business rules across legacy and modern systems.

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Work Experience

Inside Real Estate

Senior Software Engineer · 2023–Present

Leading frontend and full-stack product work across CRM modernization, internal ad tech tooling, and cross-system debugging at a platform serving 200,000+ daily users. Own complex features end-to-end, influence roadmap with behavioral data, and build AI-assisted workflows that have changed how the team plans and ships.

BoomTown

Software Engineer II · 2017–2023

Contributed across frontend and backend product development on a CRM platform serving tens of thousands of real estate professionals. Worked directly with product and leadership to shape workflow-heavy features, traveled on-site to brokerages, and acted as technical liaison during client escalations.

BoomTown

QA Engineer → Associate Software Engineer · 2013–2017

Progressed from manual QA into automation engineering through demonstrated technical growth. Built and maintained a test automation framework using Cucumber, Ruby, and Selenium WebDriver. Shipped a Scala-based mobile app with AWS integrations, ramping quickly on an unfamiliar stack under active delivery pressure.

Blackbaud

Support Specialist → Senior QA Analyst · 2010–2013

Selected to work directly with early users of a newly built ticketing platform — gathering bugs, explaining product behavior, and translating feedback into structured input for product, design, and engineering. Advanced to Senior QA Analyst during a high-stakes early rollout.

Education & Credentials

Appalachian State University

B.A. Electronic Media & Broadcasting · Minor in Business

The Iron Yard

Ruby & Application Development

Stanford Online

Introduction to Databases

Certified ScrumMaster

CSM · Scrum Alliance

AWS ML Engineer Associate

In Progress · AWS Skill Builder

Contact

If you're building something interesting or just want to connect, feel free to reach out. I'm always up for thoughtful conversations about engineering, product, and making useful things better.