Staff Full Stack Engineer

Opsin; San Jose (CA); Hybrid; USD 130,000 - 180,000; Full time

Job summary

A leading company in GenAI security is seeking a Founding Engineer to shape the core product. You will work closely with founders and customers, engaging in both backend and frontend development, while contributing to the company’s mission of ensuring secure AI use. This role is pivotal for those passionate about AI and cybersecurity in a fast-paced startup environment.

Benefits

Competitive salary

Benefits and equity

Early impact on product development

Collaboration with founders and tech leads

Qualifications

• 4-10+ years of experience in core software engineering.
• Experience with modern frameworks like React and Next.js.
• Ability to design and implement scalable systems.

Responsibilities

• Build and own foundational product features.
• Design and implement scalable backend services and APIs.
• Participate in end-to-end engineering processes.

Skills

Software Engineering

Scalable Systems Design

API Design

Frontend Development

Problem Solving

Collaboration

Education

Bachelor's Degree in Computer Science or related field

Tools

React

Node.js

TypeScript

Job description

As aFounding Engineer, you’ll help define and build thecore foundationof our product. You’ll work across the stack,own key features end-to-end, and collaborate closely withfounders, customers, and tech leadsto shape the future ofGenAI security.

What You’ll Do

• Build and ownfoundational product features
• Work directly withearly customersto iterate on solutions
• Design and implementscalable backend services, data tiers, and APIs
• Contribute tofull-stack development, including frontend components in modern frameworks
• Participate inend-to-end engineering, from design to DevOps

Your Experience &Skills

• 4–10+ yearsof experience incore software engineering
• Experience buildingfront end componentsinmodern frameworkssuch as React, Next.js, and similar
• Experience designingscalable systems, APIs, and data architecture
• Experience shippingproduction softwarein aproduct-focused environment
• Ability towork through ambiguity and solve complex technical problems
• (Desirable) Experience working withGenAI or MLin aprofessional, personal, or academic setting
• (Desirable) Familiarity withTypeScript and the Node.js ecosystem

Mindset &Fit

• Collaborative—thrives in afast-paced startupenvironment
• Strong opinions, loosely held—willing to debate, iterate, and adjust
• Bias for action—prioritizes, ships fast, and avoids over-engineering
• Passionate about AI and cybersecurity
• Desire to have impacton all aspects of the company’s success

Why Join Us?

• Early impact:Help shape a category-defining product inGenAI security
• Growth & ownership:Work directly withfounders and tech leadsto drive innovation
• Cutting-edge tech:Build withLLMs, AI security, and enterprise AI adoption strategies

Excited to secure the future of GenAI? Join us!

About @Opsin

Opsin is aventure-backed GenAI security company, funded bytop-tier investors including Race Capital. We enable enterprises to safely adopt GenAI solutions likeMicrosoft Copilot, Google Gemini, and other LLM-powered agentsbymonitoring and securing enterprise data access. Our platform ensures employees can leverage AI without exposing sensitive or over-permissioned information.

Employment Type

Full-Time

Compensation

Competitive salary, benefits, and equity

Location

San Jose, CA / SF Bay Area (hybrid). The team works together in person at our locations in downtown San Jose and San Ramon. In-person collaboration is key for this role.

Seniority level

• Seniority level

  Mid-Senior level

Employment type

• Employment type

  Full-time

Job function

• Job function

  Engineering and Information Technology

• Industries

  Technology, Information and Internet

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