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Frontend design engineer, building interfaces that feel right.
I work at Flagsmith. For over ten years I have been building design systems and React interfaces, with a soft spot for accessibility and the small details of motion. The lab is where I polish those details in public.
From the lab
All components →- npx shadcn add @tcosta/copy-button
- A shared layoutId lets the pill travel between tabs instead of blinking.
Work
- Present
Flagsmith · Frontend Design Engineer
Frontend and UI for an open-source feature flag platform.
- 2022 – 2025
Calendly · Frontend Design Engineer
Led the UI design system used across every frontend team: 30+ accessible React components, Storybook, CI and DX.
- 2021 – 2022
Hugo (acquired by Calendly) · Senior Software Engineer
Shipped product features with React, Node.js and PostgreSQL; integrations with ClickUp and Microsoft Teams.
- 2020 – 2021
Grupo MContigo · Fullstack Developer
Scaled Next.js products serving 100M+ monthly visits.
- 2020 – 2021
Adireto · Team Lead & Fullstack Developer
Led a team of three and built a testing culture that cut production bugs.
- 2015 – 2020
Amplisoftware · Team Lead & Fullstack Developer
React, Node.js and React Native apps, including a real-time chat platform.