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Lionel Sim

PROFILE

Lionel Sim

Over four months, contributed to the LifeSG/react-design-system repository by building and enhancing accessible, reusable UI components using React, TypeScript, and CSS. Focused on accessibility, the work included keyboard navigation and ARIA improvements for calendar components, semantic HTML updates for assistive technology support, and responsive UI/UX enhancements for dropdowns and time pickers. Developed features such as OTP input with external control and multi-select popover overlays, supported by comprehensive unit testing. Each feature addressed usability, layout stability, and maintainability, resulting in more inclusive, robust interfaces and smoother user flows across authentication, booking, and general component interactions within the design system.

Overall Statistics

Feature vs Bugs

100%Features

Repository Contributions

14Total
Bugs
0
Commits
14
Features
5
Lines of code
1,246
Activity Months4

Your Network

83 people

Same Organization

@gt.tech.gov.sg
12

Shared Repositories

71
AnuMutyalaMember
Ashley TeoMember
BenedictMember
benjamin leongMember
benjaminLeongSKMember
benjaminLeongSKMember
Choo Chen WeiMember
Ha Dang NguyenMember
DarrelMember

Work History

March 2026

5 Commits • 2 Features

Mar 1, 2026

March 2026: Delivered core UI component enhancements in LifeSG/react-design-system with a focus on OTP flows and multi-select UX. Implemented OTP Input Enhancements with ref exposure, external-control props, and OTP-only mode, backed by unit tests for cooldown behavior and prop-driven rendering. Enhanced Popover with a nested overlay for multi-select and resolved a dismissal issue when a sibling portal is focused, improving UX consistency. Updated API documentation via props table alignment to support maintainability. Business impact: smoother OTP-based authentication, fewer UI glitches, and faster, safer feature rollouts. Technologies demonstrated: React component design patterns (refs and props APIs), comprehensive unit testing, nested overlay UX, and stability fixes.

January 2026

2 Commits • 1 Features

Jan 1, 2026

January 2026 monthly summary for LifeSG/react-design-system: Key UI/UX improvements focused on responsive dropdowns and time range picker width handling. Implemented CSS width fixes and dynamic width adjustments to improve usability across screen sizes, and added min-width constraints to stabilize dropdown rendering. These changes enhanced the reliability of booking-related UI components, reducing edge-case layout issues on diverse devices and contributing to a smoother user journey.

December 2025

2 Commits • 1 Features

Dec 1, 2025

Month: 2025-12 — Focused on accessibility improvements in LifeSG/react-design-system, delivering semantic HTML enhancements and default rendering changes for VisuallyHidden and ProgressIndicator. This work improves assistive tech support, consistency across components, and sets a foundation for further accessibility improvements.

May 2025

5 Commits • 1 Features

May 1, 2025

Performance review month 2025-05: Delivered accessibility-focused calendar enhancements in LifeSG/react-design-system, focusing on keyboard navigation, ARIA labeling, and focus management for the calendar component. Implemented min/max date range constraints and new day-cell props to improve usability and reusability. This work strengthens inclusivity, reduces onboarding friction for keyboard-only users, and enhances the design system's capability for accessible components.

Activity

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Quality Metrics

Correctness92.8%
Maintainability88.6%
Architecture87.2%
Performance87.2%
AI Usage22.8%

Skills & Technologies

Programming Languages

CSSJavaScriptTypeScripttsx

Technical Skills

AccessibilityComponent DevelopmentDate HandlingFront End DevelopmentFront-end DevelopmentFrontend DevelopmentKeyboard NavigationReactTypeScriptUI Component DesignUI ComponentsUI DevelopmentUI/UXaccessibilityfront end development

Repositories Contributed To

1 repo

Overview of all repositories you've contributed to across your timeline

LifeSG/react-design-system

May 2025 Mar 2026
4 Months active

Languages Used

CSSJavaScriptTypeScripttsx

Technical Skills

AccessibilityComponent DevelopmentDate HandlingFront-end DevelopmentFrontend DevelopmentKeyboard Navigation