There are many many threads debating Salesforce team development. One sandbox vs multiple (i.e, one per developer).
I would prefer to work in my own dev org, but I always decide against it when I remember the following scenario:
DEV1 works in sandbox1. He adds a call to a new method1 in the Account trigger before update handler. When all is said and done, the transaction includes 100 SOQL statements, and oh, I don't know... 6 seconds cpu time.
DEV2 works in sandbox2. He adds a call to a new method2 in the Account trigger before update handler. When all is said and done, the transaction includes 101 SOQL queries, and oh, I don't know... 6 seconds cpu time.
Each developer's work compiles and runs without issue. But then they merge into a shared dev sandbox, and, as now 201 SOQL queries will be run (not to mention running over the max cpu time), everything breaks.
What's the solution here? I say work in the same sandbox and communicate and plan accordingly. I can't think of a better way.
But does that scale? Can a company with 100 developers work in the same sandbox? Can they all communicate and plan accordingly? Is it practical? But if they don't.. they'll potentially hit the limits once they merge. Better work in the same sandbox and know earlier rather than later, no?