About this opportunity
Harnham lists this Principal Frontend Engineer opportunity in white plains, New York. Review the employer’s description below for duties, qualifications and application requirements.
Job description
Principal Frontend Engineer
Hybrid (NYC)
$150k - $200k Base + Bonus & Equity
Overview
The organisation builds large‑scale, consumer‑facing platforms used by hundreds of millions of users worldwide, with a strong focus on quality, long‑term maintainability, and responsible AI‑assisted development. This role sits within a financial products marketplace that partners with major financial institutions to deliver personalised consumer experiences. The position is ideal for a senior‑level engineer who values engineering judgement, thoughtful architecture, and technical leadership over speed alone.
Responsibilities:
Own and uphold a high engineering quality bar across design reviews, code reviews, testing strategy, and production readiness
Collaborate closely with product, design, and engineering partners to shape solutions and evaluate technical trade‑offs
Architect and build frontend‑leaning, full‑stack systems that are modular, composable, and resilient to change
Champion performance, reliability, and maintainability in AI‑assisted development environments
Apply functional programming principles and immutability to reduce side effects and improve system clarity
Lead the effective use of AI agents for prototyping, refactoring, and exploration while ensuring production‑grade outcomes
Drive a robust automated testing strategy across unit, integration, UI/component, and end‑to‑end layers
Provide technical leadership through mentorship, delegation, and high‑quality code reviews
Must‑Have Qualifications
Bachelor's degree in Computer Science, Engineering, or a related field
5+ years of experience building production web applications, including senior‑level ownership
Prior experience operating at principal, lead, or staff engineer level
Expert proficiency with TypeScript and React , including server‑side rendered frameworks such as Next.js
Strong understanding of functional programming concepts and immutability in modern frontend systems
Advanced knowledge of automated testing strategies and CI‑driven feedback loops
Who can apply
Review the original listing for work authorization, qualifications and employer requirements.