Jinelle
Baterna

Frontend engineer. Based in Toronto, Canada.

I build fast, well-tested React interfaces that hold up in production, but what I actually care about goes deeper than shipping a component that works: performance, reliability, and code that's optimized and built to be reused instead of rebuilt every time requirements change. I loop in AI for prototyping, reviewing my own code, and testing, but I still hold what it gives me to the same bar as my own work: does it perform, is it accessible, is it actually good code. The small stuff is what shows it: a render that doesn't jank, a design that still looks right after handoff. Most of my best work happens where design and engineering overlap.

Experience

Recent roles. Full history on the résumé.

Mosaic Manufacturing Ltd

Frontend Developer | May 2021 | Toronto, ON, Canada

  • React
  • Redux
  • TanStack Query
  • TypeScript
  • Styled Components
  • Figma
  • Jest
  • React Testing Library
  • Playwright
  • Proposed and led a component refactor, negotiating timing to protect the release and de-risking it with new test coverage. Cut code duplication 30 to 40% and sped feature rollout 20%.
  • Main owner of frontend UI for a 6+ engineer team, handling architecture decisions, PR review, and onboarding new hires. Production bugs dropped 20%.
  • Partnered with the product designer to catch design-system and code inconsistencies before implementation, improving design-to-dev handoff speed 25% and keeping products visually consistent.

Mrkdwn, Inc.

Frontend / UX Engineer | Jan 2018 to Mar 2020

  • React
  • Redux
  • HTML
  • CSS
  • Sass
  • REST APIs
  • Sketch
  • Zeplin
  • Built a single-page React application for a Philippines-based deals and discount aggregator site, translating Sketch and Zeplin designs into production UI, including deal-discovery filters and a CMS for admins.
  • Added server-side rendering so search engines could actually index the pages, and wired up REST API integration with axios to pull in live data.
  • Worked with backend engineers on caching and other performance improvements, and used analytics data to grow engagement from social and organic search, taking daily sessions past 1,000.

Skills

What I reach for, day to day.

Languages

  • JavaScript
  • TypeScript
  • HTML
  • CSS
  • Sass

AI-Native Development

  • AI-assisted build and code review loop (Claude Code)
  • Standards enforcement (accessibility, performance, design)
  • Test and spec generation
  • Prototyping and library evaluation

Architecture & Patterns

  • Component-driven architecture
  • Design systems
  • Reusable component libraries
  • State management
  • REST API integration

Testing

  • Jest
  • React Testing Library
  • Playwright

Frameworks & Libraries

  • React
  • Redux
  • TanStack Query
  • Styled Components
  • Tailwind CSS

Performance

  • Render optimization
  • Memoization
  • List virtualization
  • Code splitting
  • Profiling (Chrome DevTools, React Profiler)

Design Collaboration

  • Figma
  • Design-to-development handoff
  • Sketch
  • Zeplin

Contact

Email is the best way to reach me, but I'm on LinkedIn too.