What are the responsibilities and job description for the Sr. Data Engineer – Ontology & Semantic Modeling position at SoundThinking?
We’re building a modern data AI platform where ontologies and semantic models create a consistent understanding of entities, relationships, and meaning across systems. We are seeking a Sr. Data Engineer (Ontology & Semantic Modeling) to design scalable data pipelines, contribute to an ontology-driven semantic layer, and help improve database schema and performance across our platform. This is a hands-on senior engineering role with meaningful architectural influence.
Essential Responsibilities/Duties
Ontology & Semantic Layer
Location: Fremont, CA, Office
Hybrid Workplace
SoundThinking follows a hybrid schedule for employees who live equal to or less than 50 miles from one of our office locations, which include Fremont, CA, Tucson, AZ, Washington, D.C., Orlando, Florida, or Iselin, NJ. Employees are expected to work onsite for a minimum of 3 days per week, unless the advertised role has a specific on-site requirement. The specific days for in-office are dependent on the office location.
Note: The Company reserves exclusive right in its sole discretion to modify, adjust, delete, add or otherwise change the above at any time.
SoundThinking provides equal employment opportunities (EEO) to all employees and applicants for employment without regard to race, color, religion, sex, national origin, age, disability or genetics. In addition to federal law requirements, SoundThinking complies with applicable state and local laws governing nondiscrimination in employment in every location in which the company has facilities. This policy applies to all terms and conditions of employment, including recruiting, hiring, placement, promotion, termination, layoff, recall, transfer, leaves of absence, compensation and training.
SoundThinking expressly prohibits any form of workplace harassment based on race, color, religion, gender, sexual orientation, gender identity or expression, national origin, age, genetic information, disability, or veteran status. Improper interference with the ability of SoundThinking’s employees to perform their job duties may result in discipline up to and including discharge. If you are an individual with a disability and require a reasonable accommodation to complete any part of the application process, or are limited in the ability or unable to access or use this online application process and need an alternative method for applying, you may contact SoundThinking at careers@soundthinking.com for assistance.
The above salary is based on a good faith estimate made at the time of publication and may be modified in the future. The pay offered to a candidate may vary within this range depending on factors such as education, experience, and geographic location.
Essential Responsibilities/Duties
Ontology & Semantic Layer
- Design, evolve, and maintain ontologies, taxonomies, and semantic models
- Define entities and relationships; create mappings from source systems into semantic structures
- Establish practical governance practices (versioning, documentation, naming standards)
- Ensure semantic consistency across pipelines, APIs, and downstream applications
- Build and operate scalable pipelines using Databricks
- Design reliable, well-structured datasets and transformation frameworks
- Improve data quality through validation, deduplication, and monitoring
- Optimize Spark and SQL workloads for performance and cost efficiency
- Analyze existing Postgres schemas and query patterns to identify performance bottlenecks
- Improve table structures, indexing strategies, and data access patterns
- Review query execution plans and optimize joins and filtering logic
- Evaluate trade-offs between normalized, dimensional, and denormalized models
- Partner with engineering teams to resolve latency and scaling challenges
- Structure datasets and metadata to support LLM and agentic AI workflows
- Support retrieval use cases (RAG / hybrid search) by preparing clean, linked, high-signal data
- Collaborate with AI teams to validate semantic consistency and correctness
- Work within AWS environments (S3, IAM, compute, managed databases)
- Collaborate across data engineering, AI, product, and platform teams
- Document architecture decisions, ontology standards, and best practices
- 5 years in Data Engineering or Data Architecture
- Strong experience with Databricks Spark in production environments
- Advanced SQL and strong data modeling skills (conceptual/logical/physical)
- Strong experience with Postgres, including schema design and performance tuning
- Experience building reliable ETL/ELT pipelines
- Proficiency in Python (or Scala) for data engineering workflows
- Experience working in AWS environments
- Experience implementing data quality practices (validation, deduplication, monitoring)
- Comfortable working with ontology / semantic modeling concepts
- Knowledge graph concepts; exposure to RDF/OWL/SPARQL
- Graph databases (Neo4j, etc.)
- Experience supporting AI/ML or LLM-based systems (RAG/hybrid retrieval)
- Experience with orchestration tools (Airflow, Dagster, dbt)
- Experience with governance/lineage tooling (e.g., Unity Catalog)
Location: Fremont, CA, Office
Hybrid Workplace
SoundThinking follows a hybrid schedule for employees who live equal to or less than 50 miles from one of our office locations, which include Fremont, CA, Tucson, AZ, Washington, D.C., Orlando, Florida, or Iselin, NJ. Employees are expected to work onsite for a minimum of 3 days per week, unless the advertised role has a specific on-site requirement. The specific days for in-office are dependent on the office location.
Note: The Company reserves exclusive right in its sole discretion to modify, adjust, delete, add or otherwise change the above at any time.
SoundThinking provides equal employment opportunities (EEO) to all employees and applicants for employment without regard to race, color, religion, sex, national origin, age, disability or genetics. In addition to federal law requirements, SoundThinking complies with applicable state and local laws governing nondiscrimination in employment in every location in which the company has facilities. This policy applies to all terms and conditions of employment, including recruiting, hiring, placement, promotion, termination, layoff, recall, transfer, leaves of absence, compensation and training.
SoundThinking expressly prohibits any form of workplace harassment based on race, color, religion, gender, sexual orientation, gender identity or expression, national origin, age, genetic information, disability, or veteran status. Improper interference with the ability of SoundThinking’s employees to perform their job duties may result in discipline up to and including discharge. If you are an individual with a disability and require a reasonable accommodation to complete any part of the application process, or are limited in the ability or unable to access or use this online application process and need an alternative method for applying, you may contact SoundThinking at careers@soundthinking.com for assistance.
The above salary is based on a good faith estimate made at the time of publication and may be modified in the future. The pay offered to a candidate may vary within this range depending on factors such as education, experience, and geographic location.