Best-in-class training data, with a human touch

Our mission is to deliver high-quality data at scale by blending the right people, technology, and processes into each project. With an in-house team of expert annotators & problem-solvers, we provide data sourcing, labeling, & data annotation services for companies shaping the next generation of AI.

We believe that AI can truly serve people when it’s built on accurate, balanced, and bias-free training data.

Our story

From early research to powering next-gen AI 

Sigma co-founder and CEO Daniel Tapias researched the speech recognition and natural language processing fields for over 18 years. In the ‘90s, he made great strides in a groundbreaking project: applying automatic speech recognition to telephone services.

As AI innovations started to impact everyday life, it became clear that AI models could only be as good as the data they were trained on. From Daniel’s perspective, data quality had to be more than just accuracy —it should also involve creating balanced datasets with adequate coverage & following consistent annotation rules.
In 2008, Daniel partnered with Nuria Gómez and founded Sigma AI to help companies source, prepare, and annotate better data for better AI.

Over the years, Sigma AI has grown into a diverse, highly-trained workforce of 25K+ annotators, linguists, project managers, & subject matter experts spanning 5 continents and covering 500+ languages and dialects.

A few highlights from our journey so far:

4 out of 5 global tech titans among our long-term clients

Headquartered in Madrid, with offices in London and Miami

World leader in designing & operating secure facilities for annotating confidential data

ISO 27001 and SOC-2, Type 2 certified, and 100% GDPR compliant

4 out of 5 global tech titans among our long-term clients

Headquartered in Madrid, with offices in London and Miami

World leader in designing & operating secure facilities for annotating confidential data

ISO 27001 and SOC-2, Type 2 certified, and 100% GDPR compliant

The Sigma values

Sigma core values are infused into our teams, our relationship with clients, and the way we operate in the world at large.


Humans are at the heart of AI — and everything we do

Challenge lovers

Complex problems motivate us to do our best work

Empathetic collaborators

Our teams thrive when we understand each other perspectives

Integrity no matter what

We are mindful of the impact of our actions. We hold ourselves accountable.

Inclusive & sustainable

Diverse teams make a greater impact on the community and the planet

Our sister company:
Sigma Cognition

Sigma Cognition is an AI consultancy and full-service proof-of-concept and solutions provider. For companies venturing into AI, Cognition extends in-house AI capabilities and supports teams in developing, training and delivering custom AI solutions that solve the most complex and unique problems.

Meet our executive team

Dr. Daniel Tapias

Co-Founder and CEO
Serial AI entrepreneur and researcher with over 30 years of experience in the field. Daniel believes that AI is only worthwhile when it’s helping people. With a focus on speech and language technologies, he applied his expertise from years of research to some of the first real-world applications of speech recognition in telephone services in the early 1990s.

He led major AI initiatives as Head of UX at Telefónica Movistar and Innovation Strategy Consultant at Telefónica before breaking out as a founder, with ventures including Agnitio, Sigma.AI, and Sigma Cognition.

Daniel holds a PH.D. in electrical engineering from Universidad Politécnica de Madrid. He is co-author of three books on speech and language technologies, published over 50 papers, and taught more than 30 courses as an adjunct professor at the Universidad Autónoma de Madrid.

Nuria Gómez

Co-Founder and CFO
With over 25 years of experience in business consulting for taxation, accounting, and company acquisition and sale, Nuria Gómez is currently the Founder & CEO of Tax Planning in addition to her role as CFO of Sigma.

She has extensive international experience with US and EU multinational companies, and leads Sigma’s internationalization efforts.

An expert in domestic taxation in Spain, double taxation treaties, audit processes, and international accounting principles, Nuria holds degrees in Economics and Business (Universidad Complutense de Madrid) as well as Tax Consultancy for enterprises (Centro de Estudios Financieros).

She previously held management positions for tax consultancy at enterprises such as Cableurope (ONO Group) and Coopers & Lybrand (PwC).

Dr. Jesús Bernat

Chief Technology Officer
With a deep background in speech recognition, the Internet of Things, and insurance telematics, Jesús believes in using his passion for technology to help people and organizations. At Sigma, he leads the product teams in creating the suite of machine learning and automation technologies that make the highest-quality annotation possible at a massive scale.

Before Sigma, he held positions from CTO to innovation and people manager to researcher and lead developer — a combination of perspectives that give him a broad vision of technology within organizations.

Jesús obtained his Computer Science degree from Universidad Politecnica de Valencia and his Ph.D. in IoT from the Universidad Politécnica de Madrid, and has over 25 years of experience in AI, IoT, and speech recognition.

Antonio Hornero

Chief Operations Officer
As COO, Antonio leads the multinational project management teams that deliver the highest-quality annotation data to Sigma’s clients. He is an expert at data-driven process optimization and problem-solving, providing insights into project management practices, training, and recruiting.

He has a Master’s degree in Mathematics, an executive MBA in Economics, a postgraduate in Corporate Finance and Venture Capital, and a PADE-AMP in Business/Managerial Economics.

Previously, Antonio was CFO and COO at manufacturing companies Electrosteel and Steel Beton and held director-level positions at KPMG and Unisys.

Dr. Jean-Claude Junqua

Executive Senior Advisor
Jean-Claude Junqua has a track record of managing and leading groundbreaking innovations resulting in positive growth and profit, with over 25 years of experience as a global executive in the US, Europe, and Japan.

As Vice President of Panasonic R&D for North America, he established Panasonic’s research and development activities in Silicon Valley. After leading an internal startup at Panasonic, he has helped numerous startups and public companies innovate and reach their next level of growth.

He is convinced that mission, purpose, social good, and a collaborative customer-oriented culture are key to sustainable success.

Jean-Claude is the inventor or co-inventor of more than 100 patents and has authored 100+ peer-reviewed articles and 3 books on speech recognition and corporate and startup innovation.

Carlos Marina Civera

Chief Commercial Officer
Carlos brings to Sigma over 25 years of experience managing, scaling, and transforming companies from various sectors — including retail, health, corp facilities, and hospitality — and implementing state-of-the-art technology such as IoT, Big Data, and AI.

His career included management positions at El Corte Inglés IT department and Telefónica Group Marketing Department. In 2015, he was appointed CEO of Telefónica OnTheSpot Services, a company specializing in the digitalization of physical spaces using IoT.

Carlos is an Industrial Engineer, with an MBA from the Instituto de Empresa in Madrid. He also served as a Marketing Professor and Head of the Marketing Subject of the MBA at the IEB in Madrid and the EOI School in Madrid.

Alyssa Meritt

Chief Marketing Officer
Alyssa is a strategic marketing leader and consultant with 20+ years of experience helping organizations overcome some of their toughest digital strategy and operations problems.

At Sigma, she is focused on establishing the foundational marketing strategy and channels, building the Sigma brands, and partnering with Sales on business growth.

Her professional career includes creating and leading global SaaS professional services organizations, as well as agency and client-side marketing strategy roles. She has personally consulted with more than 10% of the Fortune 500 Companies and worked with 300+ leading global brands on digital and marketing strategy, content management, and personalization.

Her global speaking credits include SXSW, eTail West, The Online News Association, and Mobile World Congress.

Pilar Plasencia

Chief Legal Officer
Pilar is a lawyer with over 20 years of experience working with corporations and startups developing innovative technologies. She is an expert in telecommunication and new technology law, corporate law, data protection, intellectual property rights, technology transfer and licensing, national and international contracting, and more.

Building her professional career at Telefónica, Pilar’s responsibilities included leading the Legal Department, acting as Secretary of the Board of Directors for the Research and Development Center, and serving as Head of the Legal Department in the Product Innovation Unit.

Pilar holds a law degree from the Universidad Autónoma de Madrid, a Master’s in business consultancy and labor law from the Escuela de Práctica Jurídica, and a Master’s in new technology law and intellectual property rights from the Instituto de Empresa — among other courses and masters.