Data Scientist

Excelity • Herndon, VA

9d

About The Position

At Excelity, we're passionate about delivering innovative technology solutions
that help businesses thrive. Whether you're looking to streamline your
operations, improve efficiency, or enhance customer engagement, our team of
experienced professionals is here to help. So why wait? Visit excelity.io today
to learn more about how we can help you achieve your goals and take your
business to the next level.

Excelity is seeking an Ontologically Aware Data Scientist for a project
responsible for building the next generation Mission Integration Systems for an
exciting Government customer with a very critical mission. The candidate will
work with the engineering team and customer to ensure successful development of
high profile, complex, technical deliverables that are core to the continued
success of our award-winning projects.

You will design, build, and operationalize knowledge centric AI/ML systems that
integrate ontology engineering, semantic data modeling, and advanced analytics.
This role blends deep experience with RDF/OWL/SHACL and graph data models with
practical machine learning, natural language processing, and context
engineering. You will develop semantic foundations and AI-driven tooling that
enable multiple organizations to communicate using shared ontologies and that
support natural language to SPARQL interfaces with reduced hallucination.

Requirements

• A bachelor’s degree and 14 years of relevant experience OR a Master’s degree with 12 years of relevant experience OR A PhD with 9 years of relevant experience
• Prefer an advanced degree in Philosophy, Computer Science, Information Science, or a quantitative field, or equivalent experience.
• Deep proficiency in ontology languages (RDF, OWL, SHACL) and vocabularies (SKOS).
• Strong SPARQL skills; experience with semantic ETL, query optimization, and graph reasoning.
• Proficiency in Python (plus R/Java as needed) for data science, graph processing, and ML model development.
• Strong engineering practices: Git, PR workflow, testing/validation, CI/CD.

Nice To Haves

• Hands-on experience with ontology/graph platforms such as Protégé, AnzoGraph, Stardog, PoolParty, or Semaphore.
• Experience integrating disparate datasets into a unified semantic model and writing effective production-grade queries.
• Familiarity with upper ontologies (BFO, DOLCE, Common Core Ontologies, OBO Foundry).
• Knowledge of machine learning, including supervised/unsupervised methods, embeddings, and model fine tuning.

Responsibilities

• Develop and maintain logical, semantically rich, extensible ontologies (RDF/OWL/SKOS) aligned to foundational/top level ontologies (BFO, DOLCE, CCO, OBO Foundry).
• Build and evolve canonical vocabularies that unify heterogeneous datasets across organizational boundaries
• Design, implement, and maintain knowledge graphs and semantic data models using AnzoGraph including modeling tradeoffs, query optimization, and production operations.
• Create SHACL validation layers; run regular quality checks to ensure consistency, backward compatibility, and schema integrity.
• Write performant SPARQL queries; develop mapping views, CONSTRUCT transformations, and federated semantic integrations.
• Develop hybrid ontology–GenAI capabilities, including natural language to SPARQL pipelines with context engineering frameworks (e.g., DSPy) to reduce hallucination and improve schema grounding.
• Apply machine learning techniques—classification, embedding based retrieval, entity resolution, and model fine tuning—to support ontology evolution, reification, and inference.
• Partner with cross functional teams (Data Engineering, Developers, content owners) to understand information needs and deliver semantic/analytical solutions.
• Produce clear, accessible technical documentation; deliver onboarding and training for both technical and non technical users.
• Apply strong software engineering discipline to semantic assets: version control, code review, automated SHACL/dbt tests, CI/CD pipeline alignment.
• Support both new development and ongoing operations/maintenance across unclassified and classified environments.

Benefits

• Competitive salary
• Flexible work schedule
• 100% Health, Dental, Vision, and Life Insurance plans with Flexible Spending Account (FSA)
• Long and Short-term disability coverage
• Generous paid vacation and holiday time
• Safe Harbor 401(k) Retirement Plan with 6% Employer matching contributions
• Reimbursement for professional and training development
• Company-paid memberships to professional organizations

What This Job Offers

• Job Type: Full-time
• Career Level: Mid Level