Senior Software Engineer

Kastel Staffing
New York, NY

Job Description

Job Description

We're partnering with a venture-backed, engineering-first company building category-defining infrastructure in a highly complex, real-world domain. This organization is rethinking how consumers interact with a traditionally opaque system by introducing transparency, usability, and true commerce-like experiences.

Backed by top-tier investors and led by experienced founders and domain experts, the team is tackling foundational challenges with real-world impact at scale.

The Role

We’re seeking a Senior Software Engineer (5–10 years experience) who thrives in ambiguous environments and operates with high ownership.

This is a high-leverage frontend/platform role where the user experience is the product. You’ll contribute across the stack, with a primary focus on building performant, intuitive, and scalable interfaces across a multi-product ecosystem.

You’ll play a critical role in shaping frontend architecture, defining engineering standards, and influencing product direction.

Key Responsibilities

  • Build elegant, performant, and accessible user interfaces across multiple product surfaces
  • Translate complex workflows into intuitive, user-centric experiences
  • Develop reusable components and scalable frontend architecture
  • Own UI performance (load times, runtime efficiency, responsiveness)
  • Collaborate cross-functionally with Product, Design, and Backend teams
  • Contribute to API design, data modeling, and end-to-end feature delivery
  • Drive consistency through design systems and shared UI patterns
  • Write clear technical specs and mentor team members

What We’re Looking For

  • 5–10 years of frontend or full-stack engineering experience
  • Strong proficiency in TypeScript and modern frameworks (React, Next.js or similar)
  • Experience building consumer-grade, high-quality UI/UX
  • Strong understanding of performance, rendering, and state management tradeoffs
  • Experience with design systems and scalable component architecture
  • Ability to operate in ambiguity and drive clarity across teams
  • Strong communication and cross-functional collaboration skills

Nice-to-Haves

  • Experience in regulated or complex domains (e.g., healthcare, fintech, insurance)
  • Background in early-stage or scaling environments
  • Exposure to relational databases (e.g., Postgres)

Compensation & Logistics

  • Salary: $230K – $260K
  • Equity: Competitive
  • Location: New York, NY
  • Work Model: 5 days onsite (Downtown Manhattan)
  • Visa Sponsorship: Available on a case-by-case basis
  • Hiring: 1 headcount

Why This Role Stands Out

  • Category-defining company building the first true “e-commerce layer” in its industry
  • Backed by $26M Series A from top-tier investors and notable operators
  • Direct exposure to experienced founders and domain leaders
  • High-impact role owning end-to-end user experience across multiple critical products
  • Opportunity to define frontend architecture and long-term technical direction
  • Mission-driven work solving real-world access and transparency challenges

Company Snapshot.

  • Stage: Series A ($26M raised)
  • Team Size: ~30 employees
  • Founded: 2021
  • Industry: Healthcare / Ecommerce / Fintech / AI
  • Location: New York, NY

Posted 2026-03-27

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