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Senior Frontend Engineer

Sperton Global AS
Posted 10 hours ago, valid for 20 days
Location

Highland Falls, NY, US

Salary

$200,000 - $300,000 per year

Contract type

Full Time

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Here’s a more aggressive, YC-style, high-signal, 996-transparent version while keeping it professional and not legally risky:

Senior Frontend Engineer

Company: Confidential AI Infrastructure Startup
Location: Redwood City, California (Onsite, 5 days/week)
Compensation: $200,000 - $300,000 Base + Meaningful Equity
Visa Sponsorship: Available (H-1B, TN, L-1, E-3, F-1 OPT/CPT, O-1)

About the Company

We are a high-growth AI infrastructure startup building real-time voice agent systems that power customer support, sales, and operations for modern businesses.

We are backed by top-tier venture capital firms and leading angel investors. The company has scaled rapidly from early revenue to tens of millions in ARR in a short time, with a small, highly technical team operating at extreme efficiency.

This is a builder-first environment. We care about speed, ownership, and output—not process. Engineers here are expected to think like founders, move fast, and ship continuously.

The Opportunity

We are hiring a Senior Frontend Engineer to own and scale the customer-facing surface area of our AI platform.

This is a high-ownership, high-impact role. You will be responsible for building and evolving the core frontend systems that customers interact with daily—dashboards, real-time interfaces, prompt tooling, and AI workflow products.

You will work directly with founders and customers, and your work will ship to production quickly and frequently.

If you want slow-moving enterprise processes, this is not the role. If you want to build fast, own deeply, and see your work in production immediately, this is.

Responsibilities

  • Own and ship production React applications end-to-end.

  • Build and scale frontend architecture using React + TypeScript.

  • Design and implement real-time dashboards, analytics systems, and AI tooling interfaces.

  • Work directly with backend engineers to integrate APIs and ship features fast.

  • Talk to customers, understand pain points, and turn feedback into shipped product.

  • Make architectural decisions and own frontend technical direction.

  • Write clean, high-performance, production-grade code.

  • Maintain high engineering velocity while keeping code quality high.

  • Participate in rapid iteration cycles and frequent releases.

Required Qualifications

  • 3–7 years of frontend engineering experience in production environments.

  • Expert-level React + TypeScript skills.

  • Proven experience building complex, data-heavy web applications.

  • Strong understanding of frontend architecture, performance, and state management.

  • Experience working closely with backend systems and APIs.

  • Ability to operate in high-speed, high-ambiguity environments.

  • Bachelor’s or Master’s in Computer Science or equivalent technical background.

  • Comfortable working onsite in Redwood City, 5 days/week.

Preferred Qualifications

  • Experience at high-growth startups or top-tier product companies.

  • Experience building SaaS or developer-facing products.

  • Strong product intuition and customer empathy.

  • Experience working directly with founders or very small teams.

  • Full-stack exposure (Node.js or similar).

Tech Stack

  • React

  • TypeScript

  • Node.js

  • Modern JavaScript (ES6+)

  • REST APIs

  • Cloud infrastructure

  • Git

Compensation & Benefits

  • $200,000–$300,000 base salary

  • Meaningful early-stage equity

  • Full medical, dental, and vision coverage

  • $70/day meal allowance

  • $200/month wellness reimbursement

  • Visa sponsorship available

  • Direct access to founders and core product decisions

Work Style & Expectations

This is a high-intensity, high-velocity startup environment.

We operate with a bias toward speed, ownership, and execution over process. Engineers are expected to move quickly, ship frequently, and take full responsibility for their areas.

During critical product cycles, launches, or customer-driven deadlines, work intensity may increase significantly. While we do not enforce a formal 996 policy, candidates should be comfortable with startup-style intensity, including extended hours when needed to hit company goals.

We are explicit about this:
This is not a 9–5 role. It is a builder role in a company where speed matters.

Interview Process

  1. Intro Call

  2. Technical Screen (React)

  3. Deep Technical + System Design

  4. Final Onsite

If you want, I can also make a “YC Work at a Startup” ultra-condensed version or a more subtle version that still signals intensity without scaring Big Tech candidates.




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