Mattie Langenberg
Principal User Experience Engineer
Experienced full stack developer, technical leader and community builder specializing in prototyping, design systems, component libraries, and scalable UI solutions. Over 20 years of experience creating accessible, user-centric applications and building development teams.
About Me
As a developer with a background in design, I thrive in user-centered product teams. I'm passionate about the creation of scalable component libraries and design systems. My expertise spans modern javascript frameworks including React, Next, and Vue, with a focus on usability, accessibility and performance. Throughout my career, I've championed component-driven development practices, building scalable systems to support dynamic content and data-driven web applications, ranging from small MVPs to large-scale enterprise applications.
I excel at translating business requirements into technical solutions while maintaining strong partnerships with stakeholders across design, product, and engineering teams. I am a strong advocate for developer experience and continuous learning, always looking for new ways to improve myself and level up my team.
Experience
Principal UX/UI Engineer (Founding)
Jan 2024 - PresentKlearTrust
- Architect and implement full-stack solutions with NextJS in AWS (Cognito, PostGres, Lambda, CloudWatch)
- Debug issues and lead technical problem-solving efforts
- Conduct technical design reviews and guide implementation approaches
- Integrate AI tooling (Cursor, Copilot, Claude Code) into development workflow to assist with tasks including seed data generation, code consistency review, query implementation and design system component builds
- Design and maintain scalable component libraries and documentation
- Establish patterns and best practices for UI components
- Drive UX architecture decisions and development standards
- Champion design system and component-driven development practices
- Lead and facilitate agile ceremonies
- Implement AI agent supported workflows for documenting requirements, developer tasks, pull requests and release notes
- Manage technical product backlog and development roadmap
- Review PRs and maintain code quality standards
- Create and maintain GitHub actions for code quality checks (ESLint, TSC, Prettier) and test runs (Vitest, Playwright)
- Test applications and features for ease of use and performance
- Ensure UI consistency and accessibility
- Ensure applications meet requirements
Lead User Experience Engineer
Apr 2021 - Dec 2023The Office of Experience
- Designed and led implementation of Vue.js and React UI design component system
- Built Storybook UI documentation with Jest and Playwright testing
- Implemented headless CMS solutions (Storyblok, Contentful)
- Created Salesforce UI development practice for Community applications
- Managed Azure and AWS infrastructure for applications and web services
Lead Front End Developer (Founding)
Oct 2020 - Apr 2021rheli.co, Inc.
- Green field React.js development for early startup venture
- Implemented boilerplate with webpack, Jest, and Storybook
- Created GitHub Actions CI/CD for tiered Netlify environments
- Developed custom Markdown rendering and responsive layouts
Lead Front End Developer
Aug 2017 - Oct 2020Apervita, Inc.
- Led design component system development for healthcare analytics platform
- Migrated UI from Backbone.js to component-based React.js
- Managed and mentored team of five developers across Chicago and Boston
- Tech lead on multiple major feature development sprints
Group Technical Director
Jan 2017 - Aug 2017Critical Mass
- Led technology practice at Critical Mass Chicago office
- Managed projects, staff, and 3rd party vendors
- Solution architecture for enterprise projects and social campaigns
Associate Partner/Director of UI Development
Jan 2000 - Nov 2012VSA Partners
- Championed development processes and practices across organization
- Led architecture and production of all VSA digital work
- Staffed and mentored team of thirteen full-time developers
- Bridged creative team, clients, and IT partners
Skills & Expertise
Design Systems
Building scalable component libraries with Storybook, design tokens, and documentation
UI Architecture
React, Next.js, Vue.js, TypeScript - architecting accessible and performant interfaces
Accessibility & WCAG
Ensuring applications meet WCAG standards with semantic HTML and ARIA patterns
Technical Leadership
Agile ceremonies, mentoring developers, code reviews, and stakeholder collaboration
Cloud Infrastructure
AWS and Azure deployment, CI/CD pipelines with GitHub Actions and automation
Testing & Quality
Jest, Playwright, automated testing, and maintaining code quality standards
Experiments
Self indulgent mini projects. These are small development, design and prototyping projects I'm using to get to know tooling in concert with Figma, off the shelf design systems, extensions and MCP to compare results and refine my personal workflow.
Pace Calculator
A running pace calculator to help runners plan their training and race strategies. Calculate splits, pace, and speeds with variable split timing and distance configuration.
Concert Calendar
A dynamic concert calendar that pulls from ICS feeds to display upcoming shows. Share your plans with friends.
Git Rules
A collection of chatmode rules for maintaining consistent commit messages, pull request descriptions, and production release notes. These chatmodes work together to create a workflow where good commits lead to good pull requests, which in turn serve as context for generating release notes with historical links and summaries.