I have seen the following patterns implemented:<p>Pattern 1:  
* DEV VLANs + DEV Subnets  
* PROD VLANSs + PROD Subnets  
* Firewalls between DEV and PROD subnets at network layer  
   - firewall rules implemented by separate net&#x2F;sec team<p>Pattern 2:  
* DEV VLANs + DEV Subnets  
* PROD VLANSs + PROD Subnets  
* Firewalls implemented through Security Groups (cloud based platforms)  
   - firewall rules delegated to product teams<p>I would be interested to see what other patterns teams are using and how security and operations protections are achieved.