Senior Data Analyst Lead – Data Annotation & Quality

Join Milestone and build technology that pushes boundaries and empowers businesses worldwide.  

Impact & Purpose

Do you want to contribute to the AI computer vision of 2026 and beyond? If you envision that your next role will shape the future of visual machine learning and do it responsibly and with real-world impact… then please keep reading! 

Location: Barcelona, Spain.

Role Summary

As a Senior Data Analyst in Hafnia, you will own and drive our data annotation operations end-to-end. You will be responsible for designing, optimizing, and scaling annotation workflows, ensuring high data quality through robust metrics and controls, and leveraging automation and AI-assisted tooling to forecast capacity and accelerate delivery. Acting as the technical and operational authority, you will bridge data engineering, annotation operations, and AI development to ensure our datasets meet the highest standards of quality, compliance, and efficiency. 

What you will do

• Lead and manage end-to-end data annotation processes, including workflows, tooling, and collaboration with internal and external data annotators. 
• Design, optimize, and automate annotation pipelines to improve throughput, consistency, and cost efficiency. 
• Define and track annotation quality metrics (precision, recall, inter-annotator agreement, coverage, bias indicators), across both automated and manual annotations. 
• Establish quality gates, validation strategies, and audit processes to ensure datasets meet internal standards and regulatory requirements. 
• Forecast annotation bandwidth, capacity needs, and delivery timelines using AI-driven tools and data-informed planning models. 
• Integrate new annotation platforms, automation tools, and AI-assisted labeling techniques to accelerate data readiness. 
• Collaborate closely with machine learning, computer vision, compliance, and product teams to align data outputs with evolving model and business needs 
• Own documentation, governance, and continuous improvement of annotation standards and best practices

What you bring to the team

• Proven experience leading and owning the data annotation operations in an AI, ML, or data-driven environment 
• Hands-on experience working closely with annotators, annotation vendors, or large-scale labeling efforts 
• Experience with data annotation platforms, workflows, and quality assurance methodologies 
• Demonstrated success in improving data quality, efficiency, and scalability through process and tooling optimization 
• Experience collaborating with engineering and ML teams on data requirements and readiness

How you will make a difference 

• Strong background and expertise in data engineering, with the ability to design scalable pipelines for annotated datasets 
• Solid statistical and analytical skills to define, monitor, and interpret annotation quality metrics and trends 
• Proficiency in Python to support automation, tooling integrations, and data validation processes 
• Knowledge in machine learning pipelines and how training data quality impacts model performance 
• Familiarity of with AI-assisted annotation, active learning, or semi-automated labeling techniques 
• Familiarity with responsible AI principles, bias mitigation, data protection, and regulatory considerations 
• Excellent English and Spanish

About our team

You will join about 35 fantastic colleagues in a fast-growing and international team. that besides the engineering core counts profiles across go-to-market, community, product, compliance, design and strategy. We operate as an autonomous product team and share an entrepreneurial mindset and a firm belief that we can cover new grounds to the benefit of the world. We work with trust, collaboration, and flexibility as our foundations.  

What we offer

• Opportunities for professional growth and development. 
• A supportive company culture and inclusive workplace environment. 
• Daily meals, snacks, and beverages in our canteen. 
• Office amenities such as company bikes, a gym, massages, and Friday gatherings. 
• Monthly company events for team bonding and enjoyment.

Apply Now

We would like to receive your CV in English without a picture; a short custom summary may be integrated into your resume. No cover letter required. If you have any questions, you are very welcome to contact join.hafnia@milestone.dk 

We would like you to start as soon as possible, and we will hire on an ongoing basis as we interview candidates.

Join us in shaping the future of computer vision through engineering and innovation. Let’s build products, services, and your career in a meaningful way together! 

About us

Hafnia is a team within Milestone, an international company with development sites in Denmark, Bulgaria, Spain and offices all over the world. We are technology driven as we are developing and maintaining one of the most advanced video management software in the world. Innovation is not only important for us. It is a part of our DNA just as responsible use of technology which we actively support. We believe in trust, mutual respect, a healthy work life balance and room for all voices to be acknowledged. As such, we expect you to engage, speak up, and make a difference for your team, our customers, and yourself. Read more at www.milestonesys.com or hafnia.milestonesys.com for Hafnia specific information.