Data Annotator Specialist

It’s never been a more exciting time to join Vistra.   

At Vistra our purpose is progress. We believe that our clients have the power to change the world and to do great things for global progress, and we exist to remove the friction that comes from the complexity of global business – to help our clients achieve progress without friction. 

But progress only happens when people come together and take action. And we’re absolutely committed to building a culture where our people can do just that.  

We are seeking a highly skilled and motivated Data Annotator Specialist to join our dynamic and innovative team. Reporting to the Strategic Product Manager, this full-time and permanent position is based in Malaysia.

The ideal candidate will have approximately 3+ years of hands-on experience in data annotation/labelling, preferably in document AI or OCR projects. This role requires a proven ability to lead annotation teams, ensure quality assurance, and deliver high-accuracy annotations in a fast-paced environment.

Key responsibilities:

• Lead data annotation initiatives for document processing, ensuring high-quality labeled datasets for machine learning model training and evaluation


• Develop and maintain comprehensive annotation guidelines and training materials for complex document structures


• Perform quality assurance on annotated data, identifying inconsistencies and implementing corrective measures


• Collaborate with AI/ML engineers to understand model performance issues and refine annotation strategies


• Manage annotation workflows and optimize processes for efficiency and accuracy


• Train and mentor junior annotators on best practices and quality standards


• Create and maintain documentation for annotation processes and quality metrics


• Participate in cross-functional meetings to align annotation efforts with project goals


• Continuously research and evaluate emerging annotation tools and techniques to enhance productivity and quality


• Exceptional attention to detail with 99%+ accuracy in complex annotation tasks


• Strong analytical and problem-solving skills for root cause analysis


• Excellent documentation and communication skills for creating guidelines and training materials


• Ability to balance speed and quality while meeting production targets


• Leadership skills to mentor junior annotators and drive quality improvements


• Systematic approach to process optimization and continuous improvement

Key requirements:

• 3+ years of data annotation/labelling experience, preferably in document AI or OCR projects


• Proven track record of leading annotation teams or quality assurance initiatives


• Deep understanding of table structures, document layouts, and data extraction challenges


• Experience with financial documents, invoices, compliance reports, or corporate filings


• Demonstrated ability to identify patterns in ML model failures and recommend improvements


• Advanced proficiency with Excel, CSV, JSON, and structured data formats


• Strong understanding of OCR technologies, confidence scores, and bounding box coordinates


• Experience with annotation tools, quality metrics, and inter-annotator agreement calculations


• Ability to write basic scripts (Python preferred) for data validation and analysis

Bonus Experience:

• Experience with OCR/document extraction services


• Background in AI quality assurance


• Knowledge of LLM prompt engineering and evaluation


• Familiarity with financial terminology and compliance document structures


• Experience with annotation platforms (Label Studio, Prodigy, Amazon SageMaker Ground Truth)

Company Benefits:

At Vistra, we believe in putting our employees’ well-being first! We offer a flexible hybrid working arrangement and birthday leave.

Additionally, we provide comprehensive medical insurance and dental coverage, wellness allowance and competitive annual leave entitlement to support your well-being and time to recharge or explore your passions out of work.

As advocates of continuous learning and professional development, we provide an internal mentorship program and reimburse professional membership fees for certifications like CA, or ACCA, ensuring you stay ahead in your field.

If you are excited about working with us, we encourage you to apply or have a confidential chat with one of our Talent Acquisition team members. Our goal is to make this a great place to work where all our people can thrive. We hope you join us on this exciting journey!