Founding Software Engineer (Full Stack)

3fa; California; Hybrid; USD 150,000 - 300,000; Full time

Benefits offered by this job

Premium healthcare

Job summary

3fa is an early-stage startup building consumer, enterprise, and infrastructure products. You will join a small team, owning features end-to-end across multiple verticals and collaborating with design on accessible, reliable products.

We seek 1–4 years of engineering experience, with shipped production software and strong frontend/backend fundamentals. Claude Code and Codex experience is a plus; DIDs and cryptography are preferred areas.

Qualifications

• 1–4 years of engineering experience with shipped production software.
• Strong frontend and backend fundamentals.
• Experience with TypeScript and React.

Responsibilities

• Own features from definition through launch and improvement.
• Build interfaces, APIs, data systems, and commerce integrations with TypeScript and React.
• Work with design to ship accessible, reliable products.

Skills

Full-stack development

TypeScript

React

Frontend & Backend fundamentals

Tools

Claude Code

Codex

Job description

3fa is an early-stage startup working with premium retail brands to turn purchases into lasting customer relationships defined by community & culture. We build consumer, enterprise, and infrastructure products, prioritizing design, accessibility, and authenticity.

We’re quietly, but quickly, growing our team in stealth and partnering across multiple brands in fashion. You would be working directly with the founding and advisory team, taking full ownership of your work across multiple verticals.

Full-time. 50-60 hours/week. Remote, but on-site preferred. The founding team works full-time in San Francisco’s Presidio. Premium healthcare and benefits included.

Software Engineer (Full Stack)

Build products across 3fa’s consumer experiences, enterprise tools, and infrastructure.

• Own features from definition through launch and improvement.
• Build interfaces, APIs, data systems, and commerce integrations with TypeScript and React.
• Work with design to ship accessible, reliable products.

You bring 1-4 years of engineering experience, shipped production software, and strong frontend and backend fundamentals. You have practical experience with Claude Code and Codex and a strong understanding of agentic engineering workflows and architectures.

Preferred: Experience working with decentralized identifiers (DIDs), layer 2 blockchains, smart contracts, attestations, and general cryptography.

Compensation: $150,000-$300,000 annual base salary, plus meaningful equity.