Agile teams release often. Salesforce DX makes that possible: Git becomes the source of truth, and Unlocked Packages (or Managed Packages for ISVs) become the deliverable.
Moving an existing org to Salesforce DX is not trivial, though. My approach has four stages plus optional support:
1. Prerequisites
Set up the required services and give me access to:
2. Exploration
Find out early what will work and what won't.
With DXnow, I retrieve your org's metadata, turn it into a Salesforce DX project in Git and deploy it to a Scratch Org, all in the browser. That shows quickly where problems are, without weeks of manual setup.
From there I design the target Software Development Lifecycle (SDLC) and package structure. For every problem found I propose a workaround and an estimate, so you know what to expect.
3. Transition
Implement the full DevOps process and build tooling where needed (preferably open-source tools). I train your team on the new process, so development continues without interruption until go-live.
4. Go-live
Switch to the new process, with me on standby for emergencies.
5. Support (optional)
If you like, I stay on as your remote Salesforce DevOps Engineer.