Aggregate User Signups Per Day

MongoDB

Technical Specification

Use aggregation pipeline to count number of users registered per day.

Input/Output Samples

Input:users collection

Output:[{ _id:'2025-01-01', count:10 }, ...]

Optimal Logic Path

db.users.aggregate([
  {
    $group: {
      _id: {
        $dateToString: { format: "%Y-%m-%d", date: "$createdAt" },
      },
      count: { $sum: 1 },
    },
  },
  { $sort: { _id: 1 } },
]);

Architectural Deep-Dive

The aggregation pipeline is perfect for analytics like daily signup counts.