Design and evolve the open-source auth framework and enterprise platform: core architecture, public APIs, plugin and package systems, cross-runtime compatibility, reactive client state, security protocols, release quality, and OSS contributor leadership.
About Better Auth
The Role
Why You Should Join
What You'll Work On
What We're Looking For
Bonus Points
Compensation & Benefits
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.
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.
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.
- 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
- 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
- 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
- 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.
Similar Jobs
Consumer Web • eCommerce • Internet of Things
Lead developer distribution strategy and a cross-functional team to drive developer adoption of DNSid via SDKs, docs, portals, standards work, integrations, and measurable adoption signals while staying hands-on technically and managing hiring and performance.
Top Skills:
A2AAgent FrameworksAi-OrchestrationAPIsGitGoIdentity/AuthMcpPythonSdksTypescript
Cloud • Information Technology • Machine Learning
The Senior Software Engineer will develop and maintain the marimo open-source notebook, focusing on backend design, library development, and community engagement.
Top Skills:
CPythonRustSQLTypescript
Cloud • Software
We are seeking 2025 and 2026 Graduate Software Engineers to join Canonical's teams focused on open source software. Responsibilities include product roadmapping, coding in various languages, engaging with the community, and ensuring high-quality performance. Candidates should have an exceptional academic track record and experience with Linux.
Top Skills:
BashC/C++GoJavaScriptLinuxPythonRust
What you need to know about the San Francisco Tech Scene
San Francisco and the surrounding Bay Area attracts more startup funding than any other region in the world. Home to Stanford University and UC Berkeley, leading VC firms and several of the world’s most valuable companies, the Bay Area is the place to go for anyone looking to make it big in the tech industry. That said, San Francisco has a lot to offer beyond technology thanks to a thriving art and music scene, excellent food and a short drive to several of the country’s most beautiful recreational areas.
Key Facts About San Francisco Tech
- Number of Tech Workers: 365,500; 13.9% of overall workforce (2024 CompTIA survey)
- Major Tech Employers: Google, Apple, Salesforce, Meta
- Key Industries: Artificial intelligence, cloud computing, fintech, consumer technology, software
- Funding Landscape: $50.5 billion in venture capital funding in 2024 (Pitchbook)
- Notable Investors: Sequoia Capital, Andreessen Horowitz, Bessemer Venture Partners, Greylock Partners, Khosla Ventures, Kleiner Perkins
- Research Centers and Universities: Stanford University; University of California, Berkeley; University of San Francisco; Santa Clara University; Ames Research Center; Center for AI Safety; California Institute for Regenerative Medicine
