Semantic Systems Builder (Ontology & Knowledge Graph)

Position

• Position: Semantic Systems Builder (Ontology & Knowledge Graph)

• Reports to: CEO (direct report)

• Work type: Full-time / contract (negotiable)

• Location: Jung-gu, Seoul (near Dongdaemun History and Culture Park Station) + Remote available

Who We're Looking For

We are looking for a specialist who will design and evolve the dynamic ontology, knowledge graph, semantic layer, and common vocabulary that become the shared language between data and AI workflows. This role is for someone who sees ontology as an executable system asset, and who understands data consistency and common vocabulary as a long-term advantage.

Key Responsibilities

• Designing ontology models: Design ontology, entity, and relationship models

• Running semantic governance: Operate common vocabulary, schema evolution, and semantic governance

• Connecting the semantic layer: Connect structured and unstructured data into a semantic layer

• Designing retrieval & reasoning systems: Design knowledge-graph-based retrieval, reasoning, and consistency systems

• Defining the shared language: Define the common language between the data model and AI workflows

tech stack

• Semantic Modeling: ontology, knowledge graph, semantic layer, common vocabulary

• Graph / Query: RDF, OWL, SHACL, Cypher, SPARQL, graph databases

• Governance: schema evolution, semantic governance, common vocabulary, data contracts

• Data/Validation: Python pipelines, metadata, validation automation, consistency checks

• AI / Retrieval: knowledge-graph retrieval, reasoning, semantic consistency

Qualifications

• Experience with ontology, knowledge graph, or semantic modeling

• Hands-on experience with multiple tools across RDF, OWL, SHACL, Cypher, SPARQL, or graph databases

• Experience connecting semantic models to real systems and data pipelines

Preferred Qualifications

• Experience with LLM + ontology, neuro-symbolic systems, or metadata platforms

• Experience with enterprise data modeling, schema governance, or data contracts

• Experience with Python-based pipelines or validation automation

special conditions

• Common vocabulary ownership: You will own the semantic foundation for the entity, relation, and schema language used across the organization.

• Executable ontology: You will treat ontology not as a document, but as an executable system asset directly connected to retrieval, reasoning, and consistency.

Benefits & Perks

1. Environment for maximum work efficiency

· Flexible start time between 8:00 and 10:00 a.m.

· Remote work support for focused work

· Flexible leave system in 30-minute increments

· Premium massage chair and coffee machine

2. Support for family and culture

· Employee discounts on 2000Archives products

· Parents' Day carnation delivery

· Choose your own holiday gift for Lunar New Year and Chuseok

· Half-day off on your birthday

3. Support for growth

· Support for masterclasses from leaders such as Anna Wintour and Marc Jacobs

· Support for job-related books and online/offline courses

· Review of incentives and stock options based on performance

Hiring Process

Document screening → Online test → 1st interview (working-level team) → 2nd interview → Compensation discussion → Final offer

· Additional interviews or coffee chats may be held depending on the position.

· If necessary, reference checks may be conducted.

Application Materials

· Free-form resume (including career details)

· Portfolio or GitHub profile