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Justin Alfonso

Justin Alfonso

Staff Software Engineer
Raleigh, NC, US

Background

About

About

Staff software engineer with 10+ years building production web systems, from payment infrastructure to company-wide platforms and AI tooling. Known for untangling messy systems without stopping delivery, consolidating sprawling tooling into platforms teams can move fast on, and turning exploratory work into products that stick. Most effective as a high-autonomy IC who owns problems from discovery through implementation and raises the bar for the engineers around them.

Work Experience

Work Experience

  • Staff Software Engineer, TechnologyAdvice

    Jun, 2021 - Oct, 20265 years 4 months

    Promoted from Software Engineer (Jun 2021) to Senior Software Engineer (Aug 2022) to Staff Software Engineer (Jan 2024).

    • Core contributor to company-wide AI enablement, building MCP servers and agent skills that let business users query the data warehouse in plain language.

    • Built an experimentation platform for hypothesis-driven A/B testing, with an MCP so engineers could direct agents to iterate against measured results.

    • Key engineer consolidating ~30 inherited WordPress sites into one Astro deployment on Cloudflare Workers with a unified Payload CMS; discovered most of the enabling patterns.

    • Replaced ~10 tools across 3 departments with one CMS for affiliate, ads, landing pages, SEO, redirects, and takedowns; editors now do ~90% of daily work in one place.

    • Selected for a long-running tiger team; built products still in use for first-party lead tracking, invalid traffic (IVT) remediation, and ad compliance, and integrated systems from 3 acquisitions.

    • Spearheaded an incremental refactor of a Laravel/PHP/MySQL microservices platform, fixing core anti-patterns without a rewrite and improving performance, stability, and velocity.

  • Web App Developer, Advancing Technology Solutions

    Jan, 2016 - Jan, 20215 years

    • Developed and maintained a PHP/Laravel + Vue.js progressive web app for a B2B startup serving thousands of monthly users.

    • Built a PCI-compliant credit card processing system from the ground up, including a payment gateway API and SDKs for third-party integrators.

    • Designed relational database schemas, managed infrastructure as code, and built CI/CD pipelines with automated testing (PHPUnit, Jest).

  • Web Developer, Independent Contractor

    Jan, 2014 - Jan, 20162 years

    • Built WordPress sites for small-business clients with a focus on SEO, lead generation, local search visibility, and A/B-tested page performance.

  • Technical Trainer, Elephant Group

    Jan, 2012 - Jan, 20142 years

    • Promoted from new hire to trainer in 3 weeks; designed the technical training program.

  • Service Technician, Bell Techlogix

    Jan, 2011 - Jan, 20121 year

Skills

Skills

  • Languages

    TypeScript

    JavaScript

    PHP

    SQL

    Python

  • Platforms & Frameworks

    Cloudflare Workers

    Astro

    Payload CMS

    Node.js

    Laravel

    Vue.js

  • Data

    ClickHouse

    PostgreSQL

    SQLite

    MySQL

    Data warehousing

  • AI Tooling

    MCP servers

    Agent skills

    LLM-driven analytics and workflows

  • Practices

    System design

    RPC/service architecture

    Incremental refactoring

    Experimentation & A/B testing

    CI/CD

    Payment processing & PCI compliance

Education

Education

  • Computer Science, Bachelor of Science, Florida International University

    - Jan, 2020