Software Engineer, Ontology

About Fluidstack

We exist to make humanity more free. For most of human history, you farmed or you starved. Technology gave people more time for the things they wanted to do, instead of things they had to do. Powerful AI will be the biggest lever for human choice we've ever built - but only if models are aligned with what humanity actually wants. There are groups building AI who don't share these goals. Whoever deploys frontier compute infrastructure fastest will decide whether AI expands human freedom or shrinks it.

We're singularly focused on delivering 10 to 100s of GWs of compute faster than anyone else, rethinking every layer of the stack. We acquire power, design and build data centers, and operate them - with teams spanning hardware and software. Speed and scale are our key differentiators. Come be a part of building civilization-scale infrastructure for AI.

We hire people who care deeply about this problem space. If that is you, please apply!

How We Operate

• Be a barrel. Full autonomy. Own things end to end, take on scope without being asked, no permission required to operate outside your core role.
• Insane urgency. We drive everything forward as fast as possible.
• Reason from first principles. Challenge every assumption. Zero analogy thinking, no egos, the best idea wins.
• Love of the game. The frontier of AI is the most interesting problem of our time. We put in long hours at high intensity to push the frontier forward.
• Build something that actually matters. If you're going to spend your time, spend it on something that matters to the world.

The Ontology Team

Examples of key problems the team is working on

• Reduce the latency from something happening to Fluidstack knowing about it. Index operational systems, documents, conversations, and telemetry as they change, so a delayed shipment or a rack coming online becomes usable context while there is still time to act.
• Give every entity in Fluidstack's domain a shared identity. Connect a machine’s design, order, delivery, deployment, and incidents even when each system describes it differently.
• Turn what Fluidstack knows into business signals. Compare plans with observations across sites, supply chains, and compute operations, and surface the gaps that matter as the company builds at gigawatt scale.
• Build a secure platform where agents can be first-class citizens. Give agents access within each user’s permissions, with every answer traceable to its sources, freshness, and gaps in the evidence.

Role Scope

• Build the index and graph engine that connect Fluidstack’s operational data, documents, and conversations as new information arrives.
• Define the entities, relationships, and identity rules that let teams contribute knowledge about sites, equipment, orders, and incidents.
• Detect meaningful changes and publish evidence-backed signals when observed state diverges from plan.
• Give engineers and agents fast, authorized ways to query the business, with clear provenance and freshness on every answer.
• Measure change-to-knowledge latency, answer quality, and signal quality against real operational questions and events.

What We're Looking For

The below is a starting point. We always make space for exceptional people, so if you don't fit this role exactly, tell us where you would.

• You’ve built and operated a foundational data system that multiple teams relied on to make decisions or run critical workflows.
• You’ve made heterogeneous data sources work as one coherent model that people and software can rely on.
• You’ve built data platforms with extensible models that let other teams bring new domains and questions into the system.
• You’ve built systems that turn a continuous stream of changes into timely, reliable signals for operations.
• You’ve worked directly with domain experts to define what their data means and which changes matter.
• You’ve made hard calls between correctness, freshness, query speed, and access control, then revised those choices using production evidence.
• Bonus: Temporal data models (Datomic, EAVT). Search and retrieval over unstructured data. Database or indexing internals. Formal ontology and semantic web standards (RDF, OWL, SHACL, SPARQL). Physical infrastructure or inventory systems.

We are committed to pay equity and transparency.

Fluidstack is an Equal Employment Opportunity Employer. All qualified applicants will receive consideration for employment without regard to race, color, religion, sex, national origin, sexual orientation, gender identity, disability and protected veterans’ status, or any other characteristic protected by law. Fluidstack will consider for employment qualified applicants with arrest and conviction records pursuant to applicable law.

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You will receive a confirmation email once your application has successfully been accepted. If there is an error with your submission and you did not receive a confirmation email, please email [email protected] with your resume/CV, the role you've applied for, and the date you submitted your application-- someone from our recruiting team will be in touch.

Compensation: $224K - $279K