Data Annotator Specialist

Its 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 were 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 Engineering Lead, this full-time and permanent position is based in India.

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

Additional 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. General 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!