Adam Peña
Senior Full-Stack Engineer
EXPERIENCE
Founder, Full-Stack Engineer at Cindersoft
Remote • Feb 2025 - Present
- Built and launched SaaS platforms in React/Next.js, Node.js, and Python with shared UI libraries, CI/CD pipelines, and performance optimization baked in.
- Delivered AI-integrated features (real-time transcription, LLM evaluation tooling) for clients including OpenAI, Nvidia, and YC-backed startups.
Lead Full-Stack Engineer at Cash App
Remote • Oct 2022 - Feb 2025
- Architected and launched a cross-team marketing experimentation platform with a Node.js and React stack, improving conversion rates by 5% through faster A/B test deployment and real-time metrics via custom APIs.
- Led full stack performance initiatives, implementing server-side optimizations and front-end tuning to cut page load times by 70% and boost Lighthouse scores by 60+ points.
- Designed and deployed a headless CMS backed by custom API routes and edge functions, powering dynamic content and localization across 10+ regions without engineering support.
- Built and enforced CI pipelines for accessibility testing across marketing and product surfaces, achieving WCAG 2.1 compliance and integrating checks into the deployment process.
Senior Full-Stack Engineer at Plaid
Remote / San Francisco, CA • Aug 2019 - Sep 2022
- Led development of a modular CMS with React, Node.js, and GraphQL, cutting content release time by 60% and enabling self-serve publishing across surfaces.
- Directed Plaid’s engineering apprenticeship program, overseeing mentorship, technical curriculum (React/Node), and logistics; achieved 100% conversion across 20+ apprentices.
- Led accessibility audits and full stack remediation across web surfaces, collaborating with backend teams to address semantic data issues and reduce support tickets by 75%.
- Built and maintained a shared UI library and supporting API interfaces adopted by multiple product teams, reducing UI bugs by 30% and enabling consistent design and faster rollouts.
Software Engineer at Visibly (formerly Opternative)
Chicago, IL • Sep 2017 - Jul 2019
- Improved onboarding workflows and signup flows, increasing user retention by 25% and boosting first-time purchase conversion by 4%.
- Developed rich, interactive UI components for a proprietary online vision test, contributing to a smoother and more accurate test-taking experience.
Front-End Engineer at Arrive (formerly ParkWhiz)
Chicago, IL • Mar 2016 - Sep 2017
- Redesigned and optimized the core parking widget, increasing performance by 40% and improving booking funnel completion rates.
- Built and shipped a new B2B platform for enterprise partners, reducing client expense report processing time by 35%.
SKILLS
Frontend: JavaScript, TypeScript, React, Next.js, HTML5, CSS3, Tailwind, D3.js
Backend: Node.js, Express, Python, Django, Java, GraphQL, REST APIs
Infra: Docker, CI/CD, Serverless, Microservices, AWS, GCP
Data/AI: PostgreSQL, MongoDB, LangChain, RAG, LLM Eval, Whisper
EDUCATION
University of Illinois at Urbana-Champaign
Champaign, IL
B.S. Community Health • Dean's List
LANGUAGE
English (native), Spanish (fluent), Japanese (conversational, working toward JLPT N3)