Kalle Rosenbaum has worked as a software developer for 20 years. His passion for Bitcoin began in 2013 and has continued uninterrupted. Kalle started a Bitcoin consultancy company in 2015 and has worked in the Bitcoin industry since then. He also writes a technical blog that explains various technical Bitcoin topics, such as block-propagation improvements, sidechains, and replace-by-fee. The purpose of the blog is to teach himself and let others benefit, too.