About Us

Hashtag Integration is an expert on Solution Architecture and Integration


We have over 20 years of experience in complex environments, governing Integration architectures and designing best-in-class solutions

“We commit to the success of clients – beyond the scope of our the assignments”


20 years of experience in various Industries and process domains


In depth experience on Solution and Integration Architecture in complex environments


Skilled stakeholder managers and excellent communicators

Hashtag Integration, a brief history

Harald Kastelijn is eager to learn and seeks challenges for personal development. His fascination with technology and programming started at an early age.


This helped him earn a bachelor’s degree in computer science and in 1998 he started his career as SAP ABAP developer. He quickly discovered his interest in application integration and pursuit this interest working for multinationals such as Shell, Unilever and Heineken.


In 2005 he took his next career step and joined Philips. Over the next 10 years he learned about Integration and Solution Architecture – but also about the inner workings and challenges found in complex organizations.


In 2015 he left Philips for a new challenge, starting an IT consulting firm. Recognizing the increasing importance of Integration he founded Hashtag Integration. Its mission is to help organizations enable Integration and achieve Digital Transformation.


His believe to commit to the success of clients, beyond the scope of the assignment, is the guiding principle for Hashtag Integration today.

Our mission and vision

Our mission is to help you achieve Digital Transformation and enable Integration

We want to be recognized as your trusted transformation partner

Our clients