Senior Software Engineer, Identity & Collaboration Together.ai is looking for a Senior Software Engineer to take a leading role in the authentication, authorization, and collaboration systems that every Together product depends on. As part of the Product Foundations engineering group, the Identity & Collaboration team owns authentication flows (including SSO and OAuth), organizations, projects, API keys, and the role-based access controls that enable secure collaboration at scale. Every customer interaction with Together relies on the systems we build. Whether it's a researcher accessing their models, an enterprise team collaborating on a shared project, or a developer making an API call, we make authentication seamless and invisible for simple cases while providing robust, enterprise-grade capabilities for complex organizational structures. Our work directly enables Together's growth from individual users to large enterprise teams, and we're actively building the next generation of collaboration features that will unlock new ways for customers to work together securely and efficiently across all Together products. About the Role Location: Hybrid in Amsterdam, NL Full-time: This means 40 flexible hours, Monday through Friday. You'll work with a good deal of autonomy, owning meaningful pieces of our identity and access platform end-to-end, spotting problems worth solving, and contributing to the team's technical direction. You'll also help raise the bar around you through code and design review and by supporting more junior engineers. Responsibilities Design and own authentication and authorisation systems end-to-end: SSO, OAuth/OIDC, SAML, organizations, projects, API keys, and role-based / attribute-based access control Make and document the technical decisions that shape how identity works across every Together product Build across the stack — Elixir/Phoenix services on the backend and TypeScript/Next.js on the frontend — and the APIs other teams build on Contribute directly to our Next.js product surface and the API layers behind it Run the Elixir/Erlang VM (BEAM) in production Identify and address technical debt and security risk in our area with sound judgment Treat code and design review as a core part of your contribution, and mentor more junior engineers Represent the team in cross-functional discussions on identity and security Maintain our systems to a high standard of code quality, documentation, automated testing, and continuous delivery Work with relational (PostgreSQL) and non-relational (MongoDB) data Requirements Around 4–5 years of professional experience building production software (a mid-to-senior role rather than a staff-level one) Experience with authentication and authorization in production — OIDC, SAML, OAuth, JWT, RBAC, ABAC, and SSO — with a real understanding of the security tradeoffs involved Strength in at least one of: functional backend (Elixir/Phoenix or another functional language such as Erlang, Scala, Clojure, Haskell, F#, or OCaml) or TypeScript (backend and/or frontend, for example with Next.js) Strong technical judgment, with a track record of maintainable, well-crafted solutions Comfortable breaking ambiguous problems into executable work and using prototypes and demos to de-risk Treats code and design review as a core part of their contribution, and helps develop the engineers around them A clear communicator who influences peers through strong technical output Willing to become proficient in Elixir and Phoenix if not already About Together AI Together AI is a research-driven artificial intelligence company. We believe open and transparent AI systems will drive innovation and create the best outcomes for society, and together we are on a mission to significantly lower the cost of modern AI systems by co-designing software, hardware, algorithms, and models. We have contributed to leading open-source research, models, and datasets to advance the frontier of AI, and our team has been behind technological advancement such as FlashAttention, Hyena, FlexGen, and RedPajama. We invite you to join a passionate group of researchers and engineers in our journey in building the next generation AI infrastructure. Compensation We offer competitive compensation, startup equity, and other competitive benefits. Our salary ranges are determined by location, level and role. Individual compensation will be determined by experience, skills, and job-related knowledge. Equal Opportunity Together AI is an Equal Opportunity Employer and is proud to offer equal employment opportunity to everyone regardless of race, color, ancestry, religion, sex, national origin, sexual orientation, age, citizenship, marital status, disability, gender identity, veteran status, and more