Senior Software Engineer, Ontology & Reasoning Systems

Protegrity

Senior Software Engineer at Protegrity designing ontology and reasoning systems. Unifying enterprise data into a single deterministic reasoning model to enhance data protection.

Posted 6/25/2026full-timeConnecticut • Connecticut, New York • 🇺🇸 United StatesSenior💰 $237,600 - $266,700 per yearWebsite

Tech Stack

Tools & technologies

GoJavaNeo4jPythonRustScala

About the role

Key responsibilities & impact

Own the ontology and rule layer that unifies structured, semi-structured, and unstructured enterprise data into a single reasoning model.
Model entities, relationships, events, and constraints across heterogeneous sources, and develop rules that derive conclusions from combinations of facts.
Use LLMs at the ingestion boundary for extraction, normalization, and categorization, with appropriate validation of model-generated outputs.
Make system findings traceable by connecting each conclusion to the source facts and rules that produced it.
Build retrieval capabilities, including vector search, keyword search, and graph traversal, to support reasoning workflows.
Improve quality through entity resolution, constraint modeling, and structured handling of conflicting or overlapping sources.
Ship production services and research prototypes with a focus on correctness, reliability, and maintainability.

Requirements

What you’ll need

5+ years of experience building backend systems in a modern language such as Python, Go, Java, Scala, Rust, or similar, or equivalent practical experience.
A strong formal and mathematical foundation, including discrete mathematics, logic, and graph theory.
The ability to reason about soundness, completeness, and tractability, and to express complex domains as formal rules and constraints.
Hands-on experience with declarative, logic-based, or rule-based reasoning systems such as Datalog, Answer Set Programming, constraint logic programming, Prolog, production rule engines, SMT solvers, or similar.
Practical experience building LLM-powered systems, including structured extraction, RAG, or classification pipelines, with sound judgment about where model outputs require validation.
Deep experience with knowledge graphs and graph data, including RDF, SPARQL, property graphs, or graph databases such as Neo4j.
Experience designing systems whose outputs trace back to their inputs, including provenance, derivation chains, or evidence trails.
Strong debugging, testing, and validation practices, with attention to correctness.

Benefits

Comp & perks

Offers Equity
Offers Bonus
Competitive salary
Comprehensive benefits with generous vacation and holiday time off
Access to ongoing learning & development

ATS Keywords

✓ Tailor your resume

Applicant Tracking System Keywords

Tip: use these terms in your resume and cover letter to boost ATS matches.

Hard Skills & Tools

PythonGoJavaScalaRustdiscrete mathematicslogicgraph theoryDatalogProlog

Soft Skills

reasoningsoundnesscompletenesstractabilityattention to correctness