Senior Frontend Engineer at Sperton Global AS

Job description

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 • Intro Call • Technical Screen (React) • Deep Technical + System Design • Final Onsite

Requirements

Must-haves

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

Nice-to-haves

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).
Modern JavaScript (ES6+)
Cloud infrastructure

Application prep

Use the role’s language and application details while tailoring your materials.

Keywords to mirror

aireacttypescriptnode.jsjavascriptrest

Platform: teamtailor
Effort: medium

Benefits

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Dental

Vision

Wellness