Elixir Backend Engineer (Amsterdam)
Together AI
Software Engineering
Amsterdam, Netherlands
Posted on Dec 16, 2025
About the role
Together.ai is looking for a Senior Backend Engineer to join the Identity & Collaboration team, where we build the foundational authentication, authorization and collaboration features that power every product and service. Our work is mission-critical: as part of the Product Foundations engineering group, we own authentication flows (including SSO and OAuth), organizations, projects, API keys, and role-based access controls that enable secure collaboration across at scale.
Every customer interaction with Together relies on the systems we build. Whether it is a researcher accessing their models, an enterprise team collaborating on a shared project, or a developer making an API call, we ensure that authentication is seamless and invisible for simple use 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.
- Location: Hybrid in Amsterdam, NL, UK Remote & Germany Remote.
- Full-time: This means 40 flexible hours, Monday through Friday.
As a Senior Backend Engineer, you will…
- Design & Implement Elixir APIs and services that serve Together AI users
- Build service SDKs and advise other teams who consume our Elixir API in TypeScript, Golang, and Python
- Contribute to running the Elixir/Erlang VM (BEAM) in production
- Work across services to improve service integrations and replace legacy solutions
- Participate in making product and technical decisions that are in the best interest of our customers
- Maintain our systems to the highest standards of code quality, documentation, automated testing, and continuous delivery
- Work with relational (PostgreSQL) and non-relational (MongoDB) data
About you
You’ll thrive as a Senior Backend Engineer if you:
- Are an experienced backend developer and have worked with relational databases, key/value stores, and object-relational mappers
- Are willing and eager to become proficient in Elixir and Phoenix
- Have excellent programming skills, experience working in Elixir or another functional programming language is strongly preferred
- Are experienced with, or at least interested in, authentication and authorization (including abbreviations like OIDC, SAML, OAuth, JWT, RBAC, ABAC, SSO and more).
- Are proficient in TypeScript and Next.js API development
- Have a passion for working in high-performing startup teams where you can take charge of reducing ambiguity and shaping open-ended requirements
- Are curious to try and learn new things, and are not afraid to propose new approaches and make mistakes
- Excel in your communication skills, such as openly soliciting and giving feedback to improve and develop the team, constructively discussing approaches to problems faced by the team.
If you don’t meet 100% of the above qualifications, you should still consider applying. It's okay if you have not used Elixir in production yet; we understand. But if you have a passion for this technology, we want to talk to you.
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