About us.

Celeg Hannas is a small software testing company based in Tartu, Estonia.

Celeg Hannas was born from a realization that the testing approaches in practice did not fit in well with the fast-changing methodology of software development and the customers’ special needs. In 2010, Oliver Vilson founded Celeg Hannas to provide tailored software testing services to clients of all types and sizes.Our focus is mainly on testing web-based enterprise applications.Our vision is to be in a position where we have long-lasting partnerships with customers who can trust the quality of our work unconditionally.

Core philosophy

Team spirit - We understand and acknowledge that the synergy created by a team working together seamlessly is much more likely to give good results than individual efforts alone.

Competence - We strive to perfect our skills, both through constant self-learning and by regularly attending various events and trainings. We focus on learning something new every day. We challenge each other.

Drive - We are passionate about what we do. Testing is not just a job for us - it is our way of living and thinking. Testing is a state of mind.

Customer Satisfaction - Your success is our goal. As each customer is different we strive to find the settings and solutions that fit Your needs. We steer away from one-size-fits-all thinking because each software product is unique and should be treated accordingly.


Prove Expertise

Prove Expertise is considered to be one of the leading performance testing providers in Scandinavia. As a proof, they are the only company in Finland whose testers have won the "Finnish Tester of the Year" award twice.Combined with Celeg Hannas' expertise in Exploratory Testing, Test Analysis and Test Management we intend to offer more efficient testing service packages.


Codelight is web application development company located in Tartu. Their dedication to provide quality software development has created synergy between our companies


Hans Kristjaan Annuk

Business Development Manager hans.annuk@hannas.ee

Hans makes sure that our business is growing and that our clients are satisfied. He is the man who seeks to solve any problems that may occur business-wise and creates new business opportunities.

Elo Eilonen

Lead Tester elo.eilonen@hannas.ee

Elo tests stuff. Elo automates stuff. Elo likes cats.

Oliver Vilson

CTO oliver.vilson@hannas.ee

Oliver manages and spearheads testing projects, trains and coaches team members, consults customers in different Testing and QA topics and provides external training.

You seek quality...

...work with us and you shall find it. Together we can find a solution fitting your needs, so go ahead and get in touch.

Email again: