Companies like Apple and Microsoft integrate from hardware to software, or pursue related business areas
Vertical integration means build systems–CI–deployment–version control–IDE–code search–test runners are tightly connected to provide a unified workflow
Early startups are rushed with MVP and lack time/resources to build vertical integration. In open source, collaboration issues prevent it.
Horizontal Integration
Acquiring companies in fields unrelated to the current business
Often called octopus-style expansion

Seonglae Cho