Senior Ontology Engineer - Semantic Data & Knowledge Graphs

Vantor; Herndon (VA); On-site; USD 140,000 - 206,000; Full time

Benefits offered by this job

401(k) with company match

Mental health resources

Student loan repayment assistance

Adoption reimbursement

Pet insurance

Job summary

Vantor is seeking a Senior Developer to join our onsite team in the Washington, DC metropolitan area. The role requires U.S. citizenship and an active TS/SCI clearance with CI polygraph.

You will design, build, and deploy enterprise software, focusing on secure, scalable backend services and API-driven integrations in a modern stack. Join a mission-driven group delivering ontology services, knowledge graphs, and semantic data integration.

Qualifications

• We require U.S. citizenship and an active TS/SCI clearance with CI polygraph.
• We look for 10 years of experience with an advanced degree, or 15 years of experience with a bachelors degree.
• We need demonstrated experience building enterprise software in Java, Python, C#, or a similar object-oriented language.
• We require experience developing RESTful APIs, microservices, and distributed systems.
• We need experience integrating applications with relational databases, graph databases, or enterprise data platforms.
• We require hands-on experience with containerization tools such as Docker and Kubernetes or OpenShift.
• We expect familiarity with Agile development, DevSecOps practices, CI/CD pipelines, and Git-based version control.
• We need the ability to explain complex technical concepts clearly to both technical and non-technical audiences.

Responsibilities

• We design, build, test, deploy, and support enterprise applications that meet Object-Based Intelligence mission needs.
• We develop scalable backend services, RESTful APIs, and user-facing applications that connect with ontology services, knowledge graphs, semantic databases, and enterprise data platforms.
• We implement solutions using Semantic Web technologies such as RDF, OWL, and SPARQL to enable semantic search, data integration, and knowledge discovery.
• We work closely with ontology engineers, database engineers, data engineers, analysts, and Government stakeholders to turn mission needs into software solutions.
• We develop secure, containerized applications using modern engineering practices and cloud-native technologies.
• We integrate software with relational databases, graph databases, messaging systems, and enterprise APIs to improve access to mission data.
• We participate in Agile ceremonies, including sprint planning, design reviews, code reviews, and backlog refinement.
• We create automated unit, integration, and regression tests and help support CI/CD pipelines.
• We troubleshoot defects, tune application performance, and ensure our systems remain scalable, reliable, and secure.
• We prepare and maintain design documents, API specifications, implementation guides, and operational documentation.
• We support AI/ML initiatives by building services that expose semantic data, contextual knowledge, and enterprise analytics capabilities.
• We mentor junior developers and provide technical guidance while supporting knowledge transfer with Government personnel.

Skills

Java

Python

C#

Object-oriented programming

RESTful APIs

Microservices

Distributed systems

CI/CD

Git version control

Agile development

DevSecOps

Education

Advanced degree

Bachelor's degree

Tools

Docker

Kubernetes

OpenShift

Relational databases

Graph databases

Job description

Vantor is seeking a Senior Developer to join our onsite team in the Washington, DC metropolitan area. The role requires U.S. citizenship and an active TS/SCI clearance with CI polygraph.

You will design, build, and deploy enterprise software, focusing on secure, scalable backend services and API-driven integrations in a modern stack. Join a mission-driven group delivering ontology services, knowledge graphs, and semantic data integration.