Marek D.-Data Annotation & AI Training Data Specialist | LLM Evaluation | Oracle APEX / PL-SQL Developer
Check rate
Experience
LLM Data Annotation Specialist
Hexagon (Melowntech)
- Annotated and quality-reviewed complex, nuanced datasets used to train and evaluate language models.
- Worked on text-based generative AI annotation projects, following detailed guidelines and quality benchmarks closely.
- Applied critical thinking to resolve ambiguous or edge-case content, improving overall dataset consistency.
- Reported tool and workflow issues to the platform team and helped shape process and tooling improvements.
AI Data Labeling Analyst
TELUS International
- Delivered high-quality annotations and classifications for training datasets used in large language models and other generative AI systems.
- Labeled linguistic and contextual elements, including named entities, sentiment, and sensitive content, following strict client guidelines.
- Identified and anonymized personal data to keep datasets compliant with privacy standards.
- Adapted quickly to new annotation tools, taxonomies, and evolving project guidelines across several concurrent projects.
Oracle APEX / PL-SQL Developer
BBM s.r.o.
- Design and develop responsive, database-driven business applications using Oracle APEX.
- Write advanced SQL and PL/SQL procedures, optimizing queries and data structures for performance and reliability.
- Build financial and operational reports using Jasper Reports and BI tools, and maintain related internal documentation.
- Train internal users on application functionality and maintain the company's internal knowledge database.
Junior SW Tester and QA Analyst
Bohemia Interactive Studio s.r.o.
- Performed acceptance and exploratory testing for real-time simulation systems, identifying and logging defects prior to release.
- Contributed to QA documentation and supported product validation activities alongside development teams.
Industry experience
See where this freelancer has spent most of their professional time.
Experienced in Information Technology.
Business area experience
See which departments and functions this freelancer has contributed to most.
Experienced in Information Technology, Business Intelligence, Product Development, and Quality Assurance.
Summary
Data annotation specialist with 3+ years of experience labeling, evaluating, and quality-checking the datasets used to train and fine-tune language models and other generative AI systems. Comfortable working with named entities, sensitive content, and personal data, and known for staying consistent even on ambiguous or fast-changing projects. Also works as an Oracle APEX / PL-SQL developer, which brings a more structured, analytical way of thinking to labeling and evaluation work.
Skills
- Data Annotation & Labeling
- Llm Training Data
- Generative Ai Datasets
- Rlhf & Model Evaluation
- Named Entity Recognition (Ner)
- Pii Identification & Anonymization
- Data Quality Assurance
- Content Moderation & Classification
- Prompt & Response Evaluation
- Sql & Pl/Sql Development
- Oracle Apex
- Database Optimization
- Power Bi & Tableau Reporting
- Qa & Software Testing
- Technical Documentation
- Annotation & Ai Tools — Proficient Across Multiple Text, Image, And Video Annotation Platforms.
- Attention To Detail — Maintains Consistency And Precision Across High-Volume Annotation Tasks.
- Analytical Thinking — Resolves Ambiguous Cases Through Logic, Context, And Structured Judgment.
- Privacy & Compliance — Experienced Handling Sensitive Content, Pii, And Ner Annotation Standards.
- Technical Toolset — Sql, Pl/Sql, Oracle, Mysql, Jasper Reports, Power Bi, Tableau, Qa Processes.
Languages
Education
University of Economics
Ing. (M.Sc. equivalent) · Software Development, Data Analysis, Database Management, Software Quality Assurance · Prague, Czech Republic
University of Economics
Bc. (B.Sc. equivalent) · Software Development, Data Analysis · Prague, Czech Republic
Statistics
Experience
Expertise
Qualifications
Profile
Frequently asked questions
Have questions? Find more information here.
Marek is based in Hlavní město Praha, Czech Republic and prefers 100% remote projects.
Marek speaks the following languages: Czech (Native), English (Advanced), Slovak (Advanced), German (Intermediate).
Marek has at least 9 years of experience. During this time, Marek has worked in at least 4 different roles and for 4 different companies. The average length of individual experience is 2 years and 4 months. Note that Marek may not have shared all experience and actually has more experience.
Based on recent experience, Marek would be well-suited for roles such as: LLM Data Annotation Specialist, AI Data Labeling Analyst, Oracle APEX / PL-SQL Developer.
Marek's most recent position is LLM Data Annotation Specialist at Hexagon (Melowntech).
In recent years, Marek has worked for Hexagon (Melowntech), TELUS International, and BBM s.r.o..
Marek is most experienced in industries like Information Technology.
Marek is most experienced in business areas like Information Technology, Business Intelligence, and Product Development. Marek also has some experience in Quality Assurance.
Marek has recently worked in industries like Information Technology.
Marek has recently worked in business areas like Information Technology, Business Intelligence, and Product Development.
Marek holds a Master in Software Development, Data Analysis, Database Management, Software Quality Assurance from University of Economics and a Bachelor in Software Development, Data Analysis from University of Economics.
Marek is immediately available part-time for suitable projects.
Daily rate distribution
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Average rates for similar positions
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The median daily rate is the middle value of all daily rates — half of comparable freelancers charge less, half charge more. Unlike the average, it is barely affected by outliers.
Calculated based on our freelancers’ daily rates as of 15 Sep 2026. Actual rates may vary depending on seniority level, experience, skill specialization, project complexity, and engagement length.
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