Environment Strategy

One of the key tenants of DX@Scale is a simplified environment strategy that is based on these principles
Any org should be able to be recreated using artifacts and associated run books (if required)
Any development should be carried out in an individual scratch org provisioned just for the feature/task in hand
There will be no long-lived continuous integration environments
The below table details each environment and the role of each environment in a typical DX@Scale project. Projects could have variation in the number of environments in the dev channel or release channel, such as multiple integrated environments, but the below environments are absolute essential.
Environment
Type
License Type
Integrated
Role
DEV
Scratch Org
N/A
No
Development, any work item in a DX@Scale project will be developed in a scratch org. These scratch org's could be provisioned individually or fetched from a pool. Any bug fixes or hot fixes done against an existing release should be demonstrable in a scratch org. This is intended to minimize pushing features as bug fixes to production using hot fix pathway.
CI
Scratch Org
N/A
No
Validate integration of a work item from a developer against main line using just in time CI Orgs. To speed up the process, the CI orgs could be pre-provisioned using pools.
Shared Dev
Sandbox
Developer
No
This sandbox is used in a CI pipeline, where after merge, the created packages are deployed to this long lived sandbox for checking upgradeability. Can apply pre/post steps to validate deployment process.
System Testing
Sandbox
Developer
No
This environment is the first environment where all new packages will be tested. This environment will also have test data.
Staging
Sandbox
Developer Pro / Partial
Yes
Staging is the integrated environment where work items are tested against other connected environments. Test data will be deployed to this environment to make it meaningful. During the normal course of development, this environment mainly takes the role of SIT (System Integration Testing) environment. As the development nears a release, or the release branch is cut, the environment is attached to the release feed and release packages are installed. The behaviour of the system changes to User Acceptance Testing. If there are not enough integration endpoints to connect to, this environment may be only possible in one consolidated UAT environment.
Data Migration Dev**
Sandbox
Developer
No
Environment utilized by the Data Migration developers in a large program to test their data migration scripts for mock deployments. Only packages that are successfully tested in System Testing Environment should be pushed into this environment.
Data Migration Test**
Sandbox
Partial Copy
No
Used by data migration teams to test the data migration scripts on a bigger data set.
Data Migration Mock**
Sandbox
Full Sandbox
No
Used by data migration teams to test the full data migration scripts to a full sandbox to benchmark performance and data quality issues. Depending on the release model, this could be refreshed multiple times before the major release to ensure migration success.
Training**
Sandbox
Developer Pro, Partial, or Full Sandbox
No
Environment utilized for developing training assets. Depending on requirements for data sets, a partial or full sandbox may be required.
Hotfix
Sandbox
Developer Pro
No
Environment utilized to test hotfix. This environment follows the artifacts deployed to production and not necessarily one in staging during release hardening phase .
PreProd or DR (Dress Rehearsal)
Sandbox
Developer, Full Sandbox
No
Final staging environment before a release. This environment is deployed all the packages for the release and the data migration scripts are triggered ** to test the accuracy of scripts before deploying to production. Use of a Developer sandbox can be leverage for artifact deployments as they can be refreshed or created more frequently than Full Sandboxes.
Prod
Production
Production
Yes
Production Org and Dev Hub
** Denotes optional environments, only utilized during a large transformation program where salesforce is to be introduced and data must be migrated from existing solutions
If you have sufficient licenses and availability of other systems, you can remove the dual role of staging environment in the above strategy to one mentioned below, where you have a dedicated integration environment both in the develop and release channels.
Environment
Type
License Type
Integrated
Role
System Integrated Testing (SIT)
Sandbox
Developer Pro/Partial
Yes
SIT is the integrated environment where work items are tested against other connected environments. Test data will be deployed to this environment to make it meaningful. During the normal course of development, this environment mainly takes the role of SIT (System Integration Testing) environment.
User Acceptance Testing (UAT)
Sandbox
Full Sandbox
Yes
UAT is a fully integrated environment where business users test the application prior to sign-off for release to production. The environment will have at a minimum test data and most of the time contained scrubbed Production Data. This is a controlled environment with restricted System Administrator access and will the latest stable release candidate will be deployed.

Environment	Type	License Type	Integrated	Role
DEV	Scratch Org	N/A	No	Development, any work item in a DX@Scale project will be developed in a scratch org. These scratch org's could be provisioned individually or fetched from a pool. Any bug fixes or hot fixes done against an existing release should be demonstrable in a scratch org. This is intended to minimize pushing features as bug fixes to production using hot fix pathway.
CI	Scratch Org	N/A	No	Validate integration of a work item from a developer against main line using just in time CI Orgs. To speed up the process, the CI orgs could be pre-provisioned using pools.
Shared Dev	Sandbox	Developer	No	This sandbox is used in a CI pipeline, where after merge, the created packages are deployed to this long lived sandbox for checking upgradeability. Can apply pre/post steps to validate deployment process.
System Testing	Sandbox	Developer	No	This environment is the first environment where all new packages will be tested. This environment will also have test data.
Staging	Sandbox	Developer Pro / Partial	Yes	Staging is the integrated environment where work items are tested against other connected environments. Test data will be deployed to this environment to make it meaningful. During the normal course of development, this environment mainly takes the role of SIT (System Integration Testing) environment. As the development nears a release, or the release branch is cut, the environment is attached to the release feed and release packages are installed. The behaviour of the system changes to User Acceptance Testing. If there are not enough integration endpoints to connect to, this environment may be only possible in one consolidated UAT environment.
Data Migration Dev**	Sandbox	Developer	No	Environment utilized by the Data Migration developers in a large program to test their data migration scripts for mock deployments. Only packages that are successfully tested in System Testing Environment should be pushed into this environment.
Data Migration Test**	Sandbox	Partial Copy	No	Used by data migration teams to test the data migration scripts on a bigger data set.
Data Migration Mock**	Sandbox	Full Sandbox	No	Used by data migration teams to test the full data migration scripts to a full sandbox to benchmark performance and data quality issues. Depending on the release model, this could be refreshed multiple times before the major release to ensure migration success.
Training**	Sandbox	Developer Pro, Partial, or Full Sandbox	No	Environment utilized for developing training assets. Depending on requirements for data sets, a partial or full sandbox may be required.
Hotfix	Sandbox	Developer Pro	No	Environment utilized to test hotfix. This environment follows the artifacts deployed to production and not necessarily one in staging during release hardening phase .
PreProd or DR (Dress Rehearsal)	Sandbox	Developer, Full Sandbox	No	Final staging environment before a release. This environment is deployed all the packages for the release and the data migration scripts are triggered ** to test the accuracy of scripts before deploying to production. Use of a Developer sandbox can be leverage for artifact deployments as they can be refreshed or created more frequently than Full Sandboxes.
Prod	Production	Production	Yes	Production Org and Dev Hub

Environment	Type	License Type	Integrated	Role
System Integrated Testing (SIT)	Sandbox	Developer Pro/Partial	Yes	SIT is the integrated environment where work items are tested against other connected environments. Test data will be deployed to this environment to make it meaningful. During the normal course of development, this environment mainly takes the role of SIT (System Integration Testing) environment.
User Acceptance Testing (UAT)	Sandbox	Full Sandbox	Yes	UAT is a fully integrated environment where business users test the application prior to sign-off for release to production. The environment will have at a minimum test data and most of the time contained scrubbed Production Data. This is a controlled environment with restricted System Administrator access and will the latest stable release candidate will be deployed.