Adam Peña

Senior Full-Stack Engineer

adamjpena.comlinkedin.com/in/adamjpena

EXPERIENCE

Founder, Full-Stack Engineer at Cindersoft

RemoteFeb 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

RemoteOct 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, CAAug 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, ILSep 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, ILMar 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)