- Initially every engineer does everything
- Growth gives birth to independent SRE teams. Now we have engineers who does only SRE
- We realised SRE is bottle neck for product teams. SRE teams are removed and all SRE are embedded into the product teams to do dedicated work for them.
- Other team members are now required to learn SRE stuff, especially now that terraform etc are there so we are back to everyone is a SRE
note that FAANG level companies go back to independent infra, SRE etc maybe because of niche and custom softwares they have.