Jose Miguel Hernandez
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AdRoll

Staff Software Engineer · 2017–2026 · San Francisco

Staff Software Engineer on Front End Core and Ad product teams, leading design-system workflows, platform migrations, and AI-enabled product work.

This was 2017–2026—nearly a decade of platform growth, team scaling, and infrastructure evolution. The engineering challenge was keeping a 20+ application fleet moving through major framework upgrades and an AI-governance shift without breaking product velocity. I led that platform work across product, growth, and infrastructure—ten production systems shipped from it, spanning ad tooling, two brand relaunches, and the org's move into AI-assisted product development.

  • AWS
  • Python/Flask
  • TypeScript/React
AdRoll Ad Library showing approved HTML5 creative assets

Overview

Frontend platform work across ads, creative tooling, and AI systems.

  • Design systems

    Set guardrails for component ownership, visual regression, migrations, and fast product iteration.

  • Platform modernization

    Built shared frontend libraries, test systems, codemods, and React migration paths across the app fleet.

  • Product tooling

    Shipped creative, experimentation, media-planning, and AI governance work inside production systems.

Key projects

Selected work from the AdRoll years.

  1. Media Planner UI showing budget allocation for Corner Squeeze $50K campaign

    Media Planner Agent

    LLM deployment

    Engineered a production LLM agent that allocates budgets across marketing channels from natural-language conversations. Established evaluation methodology for LLM reliability; shipped with evaluation gates and monitoring to assess response quality. Deployed to sales teams in June 2026; active in prospect conversations.

    SourcesAdRoll AI Assistant - Getting Started
  2. Create Ads interface showing AI image expansion, ad copy controls, and generated AdRoll display ad sizes

    AI Ads Builder: static-to-HTML5 retrofit

    Creative interfaces

    AdRoll's ad-creation tool supported only a single rigid static-image template. Retrofitted it into an AI-powered ad builder that opens to pre-filled, brand-adapted copy and generates a six-size HTML5 ad in seconds, with AI-assisted imagery and animation. Within six months of launch, more than 250 advertisers were spending on ads made with the tool, with animated HTML5 formats accounting for most spend.

    SourcesAdRoll Static Image Web Ads Format GuidelinesAdRoll AI-Powered Ad Builder help article
  3. Product Intelligence Dashboard showing multi-source signal synthesis

    Multi-source intelligence synthesis

    LLM systems

    Built an LLM-driven pipeline synthesizing three data sources (Gong sales calls, Zendesk support tickets, Jira engineering backlog) into prioritized customer-insight signals. Established evaluation framework for signal quality and accuracy. Deployed through EngHelper AI Slackbot to executive users.

  4. Abstract design-system guardrails thumbnail showing component tiles, design tokens, validation states, and AI-assisted scaffolding

    Design-system framework for AI-assisted development

    Design system

    Built design system infrastructure enabling rapid prototyping within structured guardrails. Established ownership rules, visual-regression gates, component migration guidance, and scaffold tooling to maintain consistency across teams. Reduced approval cycles and enabled faster iteration without sacrificing deployment credibility.

    SourcesDesign system tooling and workflows
  5. Abstract React 19 migration automation thumbnail showing app windows, checklists, and connected workflow nodes

    React fleet migration coordination tooling

    Platform modernization

    Built automation and coordination infrastructure for React fleet migrations, replacing spreadsheet handoffs with agentic skills, scripts, and LOE tracking. Enabled teams to migrate autonomously while establishing repeatable patterns for future major-version upgrades. Winner of technical award for AdRoll Hack Week, May 2026.

    SourcesReact 19 official upgrade guide
  6. RollWorks is now AdRoll ABM rebrand announcement graphic

    RollWorks and AdRoll brand architecture

    Leadership

    Led frontend execution for the 2025 AdRoll brand transformation that unified RollWorks back into a single ABM platform. Refactored React components, established code ownership, and used platform automation to coordinate low-disruption launches across the unified product.

    SourcesAdRoll Announces Major Brand Transformation
  7. Innovation workspace: engineers collaborating with holographic AI interfaces and digital tools representing creativity and breakthrough thinking

    Hack Week program leadership

    Organizational leadership

    Organized NextRoll's biannual Hack Week program, a repeatable forum for engineers, PMs, designers, and business teams to test ideas outside the normal roadmap. The program produced multiple production-bound projects across creative tooling, accessibility, and AI-assisted workflows.

    SourcesCelebrating Innovation: NextRoll's Hack Week 2023 H2 WinnersHack Week Brings the HeatHack Week Delivers Innovative Projects
  8. Abstract Figma-to-AdRoll HTML5 ad generation thumbnail showing a design canvas transforming into production-ready ad variants

    HTML5 Ad Generator Figma Plugin

    Hack Week winner

    Built a Figma plugin that converted designs directly into AdRoll-ready HTML5 ads with structured exports and reusable creative patterns. Reduced manual handoffs between design and ad operations. Winner of Product Award for AdRoll Hack Week, September 2023.

    SourcesCelebrating Innovation: NextRoll's Hack Week 2023 H2 WinnersAdRoll AI-Powered Ad Builder help article
  9. AdRoll Ad Library showing approved HTML5 creative assets

    Ads microservice and management UIs

    Ads platform

    Built product surfaces around a new ads microservice: dashboard flows, ad creation interfaces, and campaign management UIs. Moved creative and campaign operations into self-serve workflows with reusable frontend patterns across the advertising platform. Also implemented AdRoll's native ad format, extending ad creation beyond static and HTML5.

    SourcesAdRoll Static Image Web Ads Format Guidelines

About AdRoll

AdRoll is a self-serve advertising platform that helps ecommerce businesses, startups, and agencies reach and convert customers across the web. The platform includes retargeting, prospecting, email, SMS, and DLV across a distributed fleet of web and mobile applications.

AdRoll.com

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