---
title: 'Software Engineer — Open Source at Better Auth'
canonical: 'https://feeny.ai/job/software-engineer-open-source-better-auth-san-francisco-g9mk4p4yvrf1'
type: 'job'
last_seen: '2026-09-10'
---

# Software Engineer — Open Source at Better Auth

- **Company:** Better Auth
- **Location:** San Francisco, CA
- **Employment:** full-time
- **Work type:** onsite
- **Posted:** 2026-04-30
- **Last confirmed live:** 2026-09-10
- **Apply:** https://jobs.gem.com/better-auth/am9icG9zdDp71mT4xWXbJ3bZFfLp-sae

## Job description

## About Better Auth

Better Auth is the most comprehensive authentication framework for TypeScript. We're the most upvoted YC Launch in history and are used by thousands of developers shipping everything from startup projects to enterprise products.

We’re a small team building foundational infrastructure that other developers depend on, so the bar is high: every decision we make affects security, correctness, and developer experience at scale. We’re also building an enterprise layer on top of the open-source framework for teams that need more operational, organizational, and compliance-oriented capabilities.

We’re now extending that work into agent auth: secure identity, approval, delegation, and capability grants for AI agents operating across runtimes, services, and organizations.

## The Role

You’ll work across the open-source core and the enterprise platform we’re building on top of it. This is not a feature-factory role. You’ll make architectural decisions that shape Better Auth’s public APIs, plugin system, runtime compatibility, reactive client behavior, and security model.

This is also a leadership role in an open-source product. You’ll help drive technical direction, maintain a high quality bar in review, mentor contributors and teammates, and make thoughtful decisions about what belongs in the framework versus what belongs in the enterprise layer.

Your work will be used by developers immediately after it ships. The decisions you make will have long-lived impacts on API stability, extensibility, and trust.

## Why You Should Join

You’ll have real ownership on a small team with outsized reach. The work here is deeply technical, highly leveraged, and lands in production quickly across thousands of developer-built products. We’re also early in a new frontier: helping define how authentication should work for AI-native products, agents, and developer tooling. If you’re excited by infrastructure at the intersection of identity, open source, and emerging AI workflows, you’ll get to shape that direction from the beginning.

This is still an early team, which means you won’t just join the culture, you’ll help define it. We value initiative, strong technical judgment, open discussion, and the humility to change course when the facts change. We care deeply about heads-down building, thoughtful API design, and giving people meaningful ownership over ambitious work.

## What You'll Work On

- Core framework architecture — auth endpoints, sessions, cookies, request context, middleware, and before/after hook pipelines
- Public API and type system design — shaping stable, ergonomic interfaces across the framework, plugins, and client libraries
- Plugin and package architecture — evolving Better Auth’s extension model across the core library and first-party packages
- Reactive client systems — designing and evolving the typed client, shared session state model, and cross-framework reactive architecture that power React, Vue, Svelte, Solid, and Lynx
- Runtime and framework compatibility — ensuring Better Auth works correctly and consistently across Node.js, Bun, Deno, Cloudflare Workers, and multiple framework integrations
- Security and identity protocols — OAuth2, OIDC, SAML, SCIM, passkeys, CSRF protections, origin validation, rate limiting, and secure session handling
- Enterprise platform foundations — helping define and build capabilities around org management, provisioning, admin workflows, observability, analytics, and operational tooling
- OSS/commercial product boundaries — deciding what belongs in the open-source framework, what belongs in the enterprise layer, and how the two compose cleanly
- Release quality and contributor experience — code review, issue triage, docs, tests, migration strategy, and safe upgrade paths for users

## What We're Looking For

- Experience level — 7+ years of software engineering experience building and shipping production systems in TypeScript
- Advanced TypeScript — You’re comfortable with complex generics, conditional types, mapped types, template literal types, and inference, and you know how to use them to design developer-facing libraries
- API Design Instinct — You think carefully about ergonomics, backwards compatibility, migration paths, and the long-term consequences of public API decisions
- Security and Platform Judgment — You’re comfortable working in auth-heavy, security-sensitive systems and can reason across sessions, tokens, redirects, CSRF, OAuth2/OIDC, and cross-runtime constraints
- Open Source Leadership — You communicate clearly, write thoughtful reviews, maintain a high quality bar, and understand the responsibility that comes with building APIs other developers depend on
- Ownership — You’re comfortable taking ambiguous, high-leverage work from idea through implementation, release, and follow-through

Bonus Points

- Experience maintaining or leading widely-used open-source libraries
- Experience building authentication, identity, developer infrastructure, or other security-sensitive systems
- Experience with plugin systems, adapter layers, or multi-package TypeScript monorepos
- Familiarity with reactive state primitives and multi-framework client libraries
- Experience building enterprise or B2B platform features such as SSO, SCIM, org management, admin tooling, auditability, or compliance-oriented workflows
- Experience thinking carefully about OSS versus commercial boundaries in developer products

## Compensation & Benefits

- Competitive salary + meaningful equity with room to grow
- Health, dental, vision
- Unlimited PTO (that we actually encourage you to use)
- SF office access + daily catered lunches & snacks

Better Auth is an equal opportunity employer. We believe diverse teams build better security infrastructure.

## About Better Auth

## Company Overview
- **One-liner**: Better Auth is an open-source authentication framework for TypeScript that lets developers implement auth flows on their own database, now part of Vercel.
- **Entity Type**: Private (Seed stage, acquired by Vercel in 2026)
- **Headquarters**: San Francisco, CA, United States
- **Founded**: 2025
- **Founders**: Not publicly available

## Core Business
- **Primary industry**: Developer tools / Authentication infrastructure
- **Target customers**: B2B and B2C developers building web applications – from side projects to enterprise systems
- **Mission**: To make high‑quality authentication something every developer can own, without outsourcing to third‑party auth services.

## Products & Services
- **Better Auth Framework**: Composable, plugin‑based authentication library for TypeScript, supporting social sign‑on, multi‑tenancy, enterprise features (SSO, SAML, SCIM), bot detection, and agent auth.
- **Better Auth Infrastructure**: Optional hosted layer that adds an admin dashboard, user management, analytics, audit logs, security detection, and global session storage.

## Market Standing
- **Valuation/Market Cap**: Not disclosed
- **Key Metric**: Total funding $5.125M (seed rounds); 13K+ GitHub stars, 350K+ monthly npm downloads, 10M+ downloads/month across frameworks
- **Notable Investors**: Peak XV Partners (lead), plus 50+ funds and angel investors
- **Growth Signals**: Rapid adoption (recommended by Next.js, Nuxt, Astro); used by ChatGPT, Google Labs, Cal.com, and many YC startups; acquired by Vercel in 2026 to accelerate open‑source auth and agent security.

## Competitive Advantages
- **Developer‑first**: Auth lives in the developer’s own codebase – version‑controlled, type‑safe, and reviewable in PRs – unlike third‑party services.
- **Ecosystem endorsement**: Official recommendation from major JavaScript frameworks.
- **Future‑ready**: Early mover in agent authentication (Agent Auth Protocol), now backed by Vercel’s infrastructure and distribution.

## Strategic Focus
- With Vercel, the team is doubling down on securing agentic workflows and integrating auth primitives into Vercel’s platform (Eve, Vercel Connect, Vercel Passport), while continuing to enhance the open‑source Better Auth framework.

## Why Work Here
- **Culture**: Small, fast‑moving team (4‑6 people) with outsized impact; thriving open‑source community (5K+ Discord, 7K+ X followers).
- **Remote/Hybrid**: Headquarters in San Francisco, but team members are distributed across the US, Uruguay, Ethiopia, and France – remote‑friendly.
- **Notable perks**: Work on one of the most widely used auth libraries; shape the future of auth for AI agents; now with Vercel’s scale and resources.
- **Current opening**: Developer Relation Engineer ($140K‑$180K + 0.25%‑1.00% equity) – blends engineering, community leadership, and content creation.

## Sources
1. [better-auth.com](https://better-auth.com)
2. [ycombinator.com](https://www.ycombinator.com/companies/better-auth)
3. [linkedin.com](https://www.linkedin.com/company/better-auth)
4. [better-auth.com/blog](https://better-auth.com/blog/better-auth-joins-vercel)
5. [ycombinator.com/jobs](https://www.ycombinator.com/companies/better-auth/jobs/eKk5nLt-developer-relation-engineer)

## Other roles at Better Auth

- [Developer Relations Engineer](https://feeny.ai/job/developer-relations-engineer-better-auth-san-francisco-k16aw3rn3ebt) — San Francisco, CA
- [Software Engineer — Agent Auth Platform](https://feeny.ai/job/software-engineer-agent-auth-platform-better-auth-san-francisco-8gw0fa9dckyp) — San Francisco, CA
- [Software Engineer — Backend Platform](https://feeny.ai/job/software-engineer-backend-platform-better-auth-san-francisco-qvr8f6f27tj0) — San Francisco, CA
- [Software Engineer — Full Stack](https://feeny.ai/job/software-engineer-full-stack-better-auth-san-francisco-kg8b225e7367) — San Francisco, CA