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
- 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.
- 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.