SymphonyAI - Principal UI Engineer - Frontend Development

About The Job

SymphonyAI is looking for a Principal UI Engineer to lead the design and delivery of high-quality, scalable web frontends. You will be hands-on, work across Angular and React, drive UI architecture and performance, and accelerate delivery using modern AI-assisted engineering tools.

Responsibilities

• Own UI architecture : Define frontend architecture, patterns, and standards for large-scale Angular/React applications.
• Hands-on delivery : Build and ship complex features end-to-end (UI, state, routing, API integration, testing).
• Component systems : Develop and maintain reusable component libraries/design systems.
• Performance & quality : Improve Core Web Vitals, bundle size, rendering performance, accessibility, and reliability.
• Mentorship & technical leadership : Guide engineers through reviews, pairing, best practices, and incident learnings.
• AI-enabled engineering : Use AI tools to speed up coding, refactoring, test generation, debugging, and documentation.
• Cross-functional collaboration : Partner with Product, Design, Backend, and QA to deliver cohesive experiences.

• 10+ years of frontend engineering experience with strong hands-on coding in production systems.
• Strong expertise in Angular (v14+) and React.
• Solid experience with PrimeNG and building reusable UI components.
• Strong knowledge of TypeScript, modern JavaScript, HTML5, CSS/SCSS, and responsive design.
• Deep understanding of SPA architecture : routing, state management (NGXS/NGRX/Redux/Zustand), and reactive patterns (RxJS).
• At least 1 year of deep usage experience in generating UI of higher quality using tools such as Cursor.

• Stabilize and improve key UI areas : performance, reliability, developer experience.
• Deliver at least 1-2 major features hands-on, end-to-end.
• Introduce or refine reusable UI patterns/components and raise code quality.
• Improve build/test speed and establish practical AI-assisted workflows.

(ref:hirist.tech)