These are some good examples of famous brands who entrusted their IT development tasks to dedicated teams:
WhatsApp. The company decided to outsource all development to keep costs low. As a result, the application was built by professionals from Eastern Europe.
Slack. The company outsourced the general design concept and redeveloped the app, logo, and website.
Skype. Skype’s founders outsourced the development of the back-end to Estonian professionals, who created the core set of features that we still use.