Planning is done. Today, building starts. Day 87 was the most important day of the entire project, not because of the features built, but because of the foundation laid. Every decision made today affects every day that follows. Custom user model, JWT authentication, environment configuration, project structure, all of it had to be right before a single feature could be built. Why the Setup Day Matters For Today In Django, two decisions made on day one are painful or impossible to reverse later. The first is the custom user model; Django's migration system ties itself so tightly to the user model that swapping it out after the first migration requires deleting the database and starting over. The second is the overall project structure; apps added or renamed later create messy migration histories and import paths. Getting both right before running any migrations meant every day after this one could focus on features rather than untangling architectural mistakes.…