Hire the Best Knowledge Representation Specialists

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Bilal B.

Fes, Morocco

$70/hr
5.0
62 jobs

I’m a Senior Knowledge Graph Architect with deep expertise in designing and implementing ontologies, taxonomies, and knowledge graphs that power intelligent systems and data-driven decision-making. My work bridges the gap between data science, AI, and semantic technologies, helping organizations structure complex information into actionable knowledge. Over the past years, I’ve worked on projects involving: - Building domain-specific ontologies (Finance, Machine Learning, HR, Healthcare, and more) - Designing and implementing Knowledge Graphs using Neo4j, Amazon Neptune, and RDF standards. - Integrating NLP and LLMs to extract, enrich, and validate knowledge from text. - Developing semantic search, recommendation, and reasoning systems. - Enabling data interoperability and standardization across enterprise systems. I’m passionate about transforming unstructured data into structured knowledge that fuels intelligent automation, contextual search, and explainable AI. My approach combines ontology design best practices, data governance, and real-world implementation experience to ensure scalable and sustainable knowledge solutions.

  • Knowledge Representation
  • Natural Language Processing
  • Machine Learning
  • Python
  • Ontology
  • Knowledge Graph
  • OWL-S
  • Graph Database
  • RDF
  • SPARQL
  • Big Data
  • Data Analysis
  • JavaScript
  • Neo4j
Sidhanth G.

Pitampura, India

$20/hr
5.0
17 jobs

I build AI systems that reason, not just match vectors. I’m an Senior Ontologist + Graph AI Engineer with 4+ years of production experience building RAG, GraphRAG, AI agents, and semantic knowledge systems with Neo4j, OWL ontologies, and LLMs. I’ve worked with Fractal Analytics, Mercedes-Benz, Philips, and QpiAI on intelligent RAG and knowledge systems. Core expertise: - GraphRAG, RAG & semantic search - Knowledge Graphs, Neo4j & Cypher - Ontology Engineering — OWL, SWRL, SKOS, RDF - Hybrid retrieval, re-ranking & query expansion - LLMs, OpenAI, LLaMA & Gemini - Pydantic & structured LLM outputs - RDF/JSON-LD data transformation - MLOps & production deployment If you’re building AI that needs to understand relationships and reason over knowledge, I can help.

  • Machine Learning
  • NLTK
  • LangChain
  • Prompt Engineering
  • LLM Prompt
  • Graph Neural Network
  • LLM Prompt Engineering
  • Vector Database
  • AI Agent Development
  • Neo4j
  • SPARQL
  • Ontology
  • RDF
  • Semantic Web Framework
  • Protege
Mohit A.

Jaipur, India

$25/hr
4.5
8 jobs

I’ve spent the last 14 years building and scaling software products, with a strong focus on AI, cloud, and backend engineering. Over the years, I’ve worked hands-on with LLMs, machine learning, NLP, OCR, recommendation systems, and AI-driven automation, along with building reliable backend systems using Python, Flask, and FastAPI. On the cloud side, I have solid experience working with AWS and designing infrastructure that is secure, scalable, and practical to operate in production. I enjoy solving the kind of technical challenges where application architecture, backend performance, and cloud infrastructure all need to work together smoothly. AI & Machine Learning Expertise - LLMs & NLP – OpenAI GPT, Anthropic Claude Sonnet, Google Vertex AI, Hugging Face BERT, Transformer Models - Conversational AI – Chatbots, Virtual Assistants, AI-driven customer support - Text Analytics & Search – Named Entity Recognition (NER), Text Summarization, Sentiment Analysis, Semantic Search - Recommendation Systems – AI-driven industry classification & harmonization of company codes (NAICS, SIC) - OCR & Document AI – AI-powered text extraction from handwritten notes & scanned documents using AWS Textract - Data Science & Deep Learning – Feature Engineering, Model Fine-tuning, Predictive Analytics - AI Automation & Optimization – Intelligent Process Automation (IPA), AI-based Data Processing Pipelines Programming & Tech Stack - Python – TensorFlow, PyTorch, Scikit-learn, FastAPI, OpenCV, Numpy, Pandas - ML Frameworks & Libraries – Transformers, LangChain - Data Engineering – Data Preprocessing, Feature Engineering, ETL Pipelines AWS Cloud & AI Services - AWS Lambda – Serverless AI automation - AWS SageMaker – AI model training, fine-tuning, and deployment - Amazon DynamoDB & RDS – High-performance NoSQL & SQL solutions - Amazon Bedrock – LLM deployment & inference at scale - Vector Search & Embeddings – Knowledge Graphs, Context-Aware AI - AWS Textract – AI-powered OCR solutions for structured & unstructured data Backend & API Development Expertise - Python Web Frameworks – Flask, FastAPI, API Development & Optimization - NGINX – High-performance API routing, Load balancing, and Reverse Proxy setup - Scalable & Secure API Development – GraphQL, RESTful APIs, Authentication, Role-Based Access Control (RBAC) AWS Cloud & Infrastructure as Code (IaC) - AWS VPC – Secure networking, private and public subnet management - AWS Lambda – Serverless computing for high-performance applications - AWS EC2 & Elastic Load Balancing (ELB) – Scalable compute instances & optimized traffic distribution - AWS Aurora & ElastiCache – High-availability databases & caching for optimized performance - AWS EFS – Scalable storage solutions for distributed applications - AWS API Gateway & Cognito – Secure API management & user authentication - Infrastructure as Code (IaC) – Terraform, AWS CloudFormation for automated deployment & scalability Database & Big Data Expertise - Relational Databases: MySQL, PostgreSQL (including Pgvector for vector search & AI applications) - NoSQL & Search Databases: DynamoDB, OpenSearch (formerly Elasticsearch) - Big Data Processing: Hands-on experience with large-scale data processing, optimization, and querying Core technical scope - Solution Architecture - Multi-Tenant Architecture - SaaS Architecture - Data Isolation - CRM Architecture - Salesforce Marketing Cloud - Workflow Automation (n8n) - Voice AI Integration - API Architecture - Webhooks & Integrations Delivery / process - Production Readiness Assessment - Architecture Review - Technical Due Diligence - Implementation Oversight - Scalability & Capacity Planning - Enterprise Customer Onboarding (Amazon/Nestlé-style vendor security reviews) Why Work With Me? - AI-powered automation – Automating workflows, AI-driven decision-making - LLM & NLP Expertise – From chatbots to AI-based text analysis & search engines - End-to-End AI Development – Data preprocessing, model selection, fine-tuning, and deployment - Cloud-Optimized Solutions – Scalable AI architectures using AWS and vector databases - AI-Driven Recommendation Engines – Industry-specific AI models for classification & personalization Let's collaborate to build cutting-edge AI solutions that transform businesses! Contact me today to discuss your next AI project!

  • AI App Development
  • Python
  • DevOps
  • Artificial Intelligence
  • AI Agent Development
  • AI Chatbot
  • Retrieval Augmented Generation
  • API Development
  • OCR Software
  • LangChain
  • Claude
  • LLM Prompt Engineering
  • LLM Prompt
  • AI Consulting
  • NodeJS Framework
  • React Native
  • Next.js
  • React
  • Automated Workflow
  • Mobile App
Hao V. P.

Ho Chi Minh City, Vietnam

$22/hr
4.3
40 jobs

🚀 Expert AI Agent Engineer | LLMs | RAG | Context Engineering | Agent Platform ⚽️ What I can do for you : ✦ Design and build multi-agent systems where specialized agents collaborate to complete complex, multi-step tasks (using LangChain, LangGraph, CrewAI, or raw OpenAI/Anthropic APIs) ✦ Implement tool-use and function-calling pipelines (web search, database queries, API calls, code execution, and custom business logic) ✦ Build RAG-powered agents that retrieve and reason over your proprietary documents (PDF, Excel, internal knowledge bases) ✦ Build GraphRAG agents backed by a knowledge graph for structured, relationship-aware reasoning ✦ Automate agentic workflows with n8n or Celery - triggered by schedules, events, or user input, running fully autonomously ✦ Deploy agents as production-ready REST APIs (FastAPI) on AWS (EC2, Lambda) with scalable, async architectures ✦ Integrate agents into your existing systems and products with clean, maintainable interfaces What I specialize in: - RAG & GraphRAG systems: including knowledge graph-powered assistants for clinical diagnosis support or Customer Support - LLM Agents & multi-agent workflows: autonomous pipelines that handle complex, multi-step user requests - LLM fine-tuning: on OpenAI, Gemini, Groq, and open-source models for domain-specific tasks - End-to-end AI pipelines: from raw data ingestion (PDF, Excel) to vectorization, retrieval, and API delivery Results I've delivered: - Built a healthcare GraphRAG assistant that processes 100MB+ clinical documents and analyzes node relationships in under 3 minutes — shipped in 1 month - Contributed to an AI brand monitoring platform that helped acquire 10 paid clients within 2 months of launch - Delivered a banking LLM chatbot achieving 80% accuracy within a 1-month development window - Achieved 92% license plate recognition accuracy on a constrained dataset of only 300 images for a Panasonic parking system Beyond execution, I actively track the latest SOTA research, reading recently published papers and integrating cutting-edge approaches directly into production systems. Your project benefits not just from solid engineering, but from knowledge of what actually works in practice right now. I'm always ready to connect. Please don't hesitate to message me.

  • Artificial Neural Network
  • Data Science
  • Python
  • Machine Learning
  • R
  • SQL
  • ChatGPT
  • Microsoft Excel PowerPivot
  • Data Analysis
  • ETL Pipeline
  • Database
  • Data Visualization
  • Microsoft Excel
  • Vision-Language Model
  • Artificial Intelligence
  • Data Warehousing & ETL Software
  • Microsoft Power BI
Allen G.

San Jose, California

$85/hr
5.0
4 jobs

I build AI systems that make it to production: machine learning and NLP pipelines, LLM and RAG applications, AI agents, and voice AI used by real customers every day. 𝐑𝐞𝐜𝐞𝐧𝐭 𝐖𝐨𝐫𝐤 - Voice AI agent platform at a healthcare technology company - Clinical document extraction system on vLLM hitting 99.99%+ accuracy on messy, unstructured files - Internal agentic coding assistant that cut time spent on repetitive engineering workflows by 80% - LiveQ, an AI desktop assistant I founded (Electron and Next.js on LiveKit): designed the full agent architecture and ran 50+ customer interviews in the first month 𝐌𝐋 𝐚𝐧𝐝 𝐍𝐋𝐏 𝐁𝐚𝐜𝐤𝐠𝐫𝐨𝐮𝐧𝐝 My experience goes deeper than the LLM wave. At Penn State's NLP lab I built a conversational agent deployed to Alexa devices reaching a 50M+ user base, and worked hands-on with transformer models (BERT, T5, XLNet), NER pipelines, OCR, and topic modeling. That history means I know when your problem needs a fine-tuned classifier instead of a frontier model, and when it doesn't need ML at all. 𝐖𝐡𝐚𝐭 𝐈 𝐂𝐚𝐧 𝐇𝐞𝐥𝐩 𝐖𝐢𝐭𝐡 - LLM applications and RAG pipelines with strict accuracy targets - AI agents and tool integrations (function calling, MCP) - Voice AI and real-time interaction systems - NLP and document AI: extraction, classification, intelligent OCR - End-to-end automation, from backend services to a polished UI 𝐒𝐭𝐚𝐜𝐤 𝐚𝐧𝐝 𝐂𝐫𝐞𝐝𝐞𝐧𝐭𝐢𝐚𝐥𝐬 Python, TypeScript, LangChain, LiveKit, Ray Serve, vLLM, Next.js, AWS and GCP. MS in Computer Science (AI) from USC. 𝐇𝐨𝐰 𝐈 𝐖𝐨𝐫𝐤 I move fast, take ownership, and communicate clearly. Send me a message with what you're building, and I'll tell you honestly whether I'm the right fit and how I'd approach it. Keywords: Artificial Intelligence, Machine Learning, Deep Learning, NLP, Natural Language Processing, Generative AI, LLM, Large Language Models, ChatGPT, OpenAI, Claude, Llama, RAG, Retrieval Augmented Generation, Vector Database, Embeddings, AI Agent, Agentic AI, Multi-Agent Systems, MCP, Model Context Protocol, Function Calling, Voice AI, Conversational AI, Chatbot, Speech-to-Text, Text-to-Speech, LiveKit, vLLM, LangChain, Ray Serve, Prompt Engineering, LLM Deployment, Document AI, Intelligent Document Processing, Data Extraction, OCR, Named Entity Recognition, BERT, Transformers, AI Automation, Workflow Automation, Python, TypeScript, Next.js, React, Electron, AWS, GCP, Healthcare AI, Full-Stack Development, Real-Time Systems

  • Machine Learning
  • Artificial Intelligence
  • Large Language Model
  • Retrieval Augmented Generation
  • AI Agent Development
  • Natural Language Processing
  • Conversational AI
  • Healthcare IT
  • Generative AI
  • Chatbot Development
  • Deep Learning
  • Prompt Engineering
  • Data Extraction
  • Amazon Web Services
  • TypeScript
  • Next.js
  • Google Cloud Platform
  • React
  • PyTorch
  • Computer Vision
Adebisi J.

Lagos, Nigeria

$35/hr
5.0
19 jobs

Full-Stack Developer | LLM | AI & ML Developer | Scalable Web Solutions| Neo4j Certified 🚀 Let’s Build Something Game-Changing! With 8+ years of Full-Stack Development experience, I specialize in crafting scalable web applications, AI-powered RAG and GRAPHRAG solutions, and enterprise-grade platforms that solve real-world problems. Whether it’s optimizing workflows, integrating AI-driven insights, or building advanced search capabilities, I focus on delivering solutions that drive real impact. I don’t just write code—I bring ideas to life. From startups to large enterprises, I ensure seamless execution, clear communication, and measurable results at every stage. Need innovation, scalability, and precision in your project? Let’s make it happen. Let’s build something great together! 💡🚀 Skills & Expertise: Full-Stack Development: PHP (Laravel), JavaScript/TypeScript (Node.js, React), Python AI & Advanced Technologies: RAG and GraphRAG architectures Database Mastery: SQL (MySQL, PostgreSQL) and NoSQL (MongoDB, Neo4j) Enterprise Integration: KYC solutions, payment systems, regulatory compliance Mobile Development: Cross-platform with React Native and Ionic Cloud & DevOps: AWS, Docker, Kubernetes Recent Successes: Led RAG/GraphRAG AI implementations for enterprise applications Boosted query performance by 40%, cutting costs by up to 40% Delivered fintech solutions for millions of users Why Choose Me: Clear communication and reliable project management Proven on-time delivery and scalable, maintainable solutions Transparent development process with regular updates Let’s create solutions that drive your business forward!

  • Python
  • Laravel
  • PHP
  • Neo4j
  • OpenAI API
  • FastAPI
  • Vector Database
  • Vector Embedding
  • AI Chatbot
  • Graph Database
  • Ontology
  • Ontology Management Software
  • Ontotext GraphDB
  • Retrieval Augmented Generation

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What does a Knowledge Representation specialist do?

A Knowledge Representation specialist structures complex domain information into formal models that machines can interpret and reason about. This role translates abstract business rules and real-world concepts into precise logical frameworks, such as ontologies or knowledge graphs. You build the underlying architecture that allows artificial intelligence systems to understand relationships between data points rather than just storing them. Your work enables automated inference engines to draw new conclusions from existing facts by following defined logical constraints.

  • Design and author formal ontology schemas using standards like OWL (Web Ontology Language) and RDF (Resource Description Framework). You define classes, properties, and constraints that accurately reflect the target domain, ensuring the structure supports automated reasoning. This involves eliciting detailed requirements from subject matter experts and converting their tacit knowledge into explicit logical axioms. Tools such as Protégé or WebProtégé help you visualize and edit these complex hierarchical structures while maintaining consistency.
  • Transform raw data into structured knowledge bases that align with your defined schema. You map disparate data sources to the ontology, resolving conflicts and ensuring semantic consistency across the dataset. This process often requires writing scripts or using extraction tools to populate RDF triples correctly. The goal is to create a unified view of information that preserves meaning and context for downstream applications.
  • Validate and debug knowledge representations by running inference checks and querying the resulting graph. You use SPARQL to retrieve specific facts and verify that the logic holds under various scenarios. When inconsistencies arise, you analyze the reasoning output to identify conflicting axioms or missing links in the model. This iterative refinement ensures the knowledge base remains accurate and useful for decision-support systems.

How to hire a Knowledge Representation specialist on Upwork

Step 1: Post a job

Define your ontology requirements and data modeling needs clearly to attract qualified candidates. Use the Job Post Generator powered by Uma™, Upwork's Mindful AI to draft a precise description. Describe your project in a few sentences, and Uma creates a tailored post for this role. You can write a new post, update a saved draft, or reuse an existing one.

  • Specify the domain concepts and relationships you need modeled, such as healthcare hierarchies or supply chain constraints.
  • List required formalisms like OWL 2 or RDF schemas so candidates know which standards they must apply.
  • Include expected deliverables such as validated ontologies or SPARQL query sets to clarify project outcomes.

Step 2: Evaluate candidates

Review portfolios for evidence of structured knowledge design and inference validation. Uma runs instant video interviews and builds shortlists with side-by-side comparisons to speed up your selection process.

  • Look for published OWL ontologies or RDF datasets that demonstrate clean class structures and property constraints.
  • Check for examples of SPARQL queries that retrieve complex relationships without returning inconsistent results.
  • Verify experience with tools like Protégé or WebProtégé through screenshots or links to collaborative projects.

Step 3: Interview your top choices

Discuss their approach to eliciting domain knowledge and handling logical contradictions. Schedule interviews within Upwork Messages to receive an immediate transcript and summary after each conversation.

  • Ask how they resolve conflicting definitions when merging multiple data sources into a single knowledge graph.
  • Request a walkthrough of a past debugging session where they fixed an inference error in an ontology schema.
  • Discuss their method for validating that the representation supports the specific automated reasoning tasks you need.

Step 4: Agree on scope and begin work

Set clear milestones for schema design, data alignment, and validation phases. Use Upwork Messages and the contract workroom to manage communication, while identity verification and Hourly Payment Protection secure your project funds.

  • Define the first milestone as a draft ontology schema with documented classes and properties for your review.
  • Require a set of SPARQL queries that test key relationships before populating the full RDF dataset.
  • Establish a validation protocol where the specialist submits debugging notes for any consistency issues found during testing.

Upwork is not affiliated with and does not sponsor or endorse any of the tools or services discussed in this article. These tools and services are provided only as potential options, and each reader and company should take the time needed to adequately analyze and determine the tools or services that would best fit their specific needs and situation.

The rates and information provided in this article are based on current data and industry sources available at the time of publication. Freelance rates can vary depending on factors such as experience, location, project scope, and market conditions. Readers are encouraged to conduct their own research to confirm current rates and trends, as this information may change over time.

How much does hiring a Knowledge Representation specialist cost?

$500-$2,500 per project is a typical range for focused Knowledge Representation specialist work. Final pricing depends on scope, technical complexity, required integrations, source-material quality, revision needs, and the freelancer's experience level.

Ontology schema design

$500-$1,200/project

Entry-level to mid-level
  • Defined domain concepts, relations, and constraints
  • Draft ontology file with classes and properties
  • Notes explaining schema structure and logic

Knowledge graph population

$1,200-$2,500/project

Mid-level
  • Populated data aligned to the ontology schema
  • Scripts or rules transforming source data to RDF
  • Summary of data consistency checks

SPARQL query development

$2,500-$4,500/project

Mid-level to senior-level
  • Collection of SPARQL queries for fact retrieval
  • Output samples verifying query accuracy
  • Instructions for executing and modifying queries

Inference engine integration

$4,500-$7,000/project

Senior-level
  • Settings enabling automated reasoning on the graph
  • Refined schema resolving logical inconsistencies
  • Technical details on connecting the inference engine

Custom knowledge system architecture

$7,000-$12,000/project

Expert-level
  • Full design for scalable knowledge representation
  • Working model demonstrating core functionality
  • Detailed documentation for future development

Frequently asked questions

Is hiring a Knowledge Representation specialist worth it?

For most businesses, yes: hiring a Knowledge Representation specialist is worthwhile. These experts build formal ontologies that allow machines to reason about your data rather than just storing it. This structure supports complex queries and automated inference that generic database designs cannot handle.

How do I evaluate Knowledge Representation specialist candidates?

Review their ability to model domain constraints using OWL or RDF schemas. Ask them to explain how they debug inference inconsistencies in Protégé or validate logic with SPARQL queries.

What tools does a Knowledge Representation specialist use?

They author ontologies in Protégé or WebProtégé using OWL and RDF standards. They query and validate the resulting knowledge graphs with SPARQL to check for logical consistency.

What deliverables should I expect from a Knowledge Representation specialist?

You receive OWL ontology schemas with documentation that defines classes and properties. They also submit RDF datasets aligned to your schema and SPARQL queries for data retrieval.