[{"_id":ObjectId("66a0da7ba1f3c14132e25980"),"operation":{"operationType":"DELETE"},"serial":"67ac96e6-0fb2-4e17-8d0f-b0718c7222ab","timestamp":NumberLong(1721817723495723670)},{"_id":ObjectId("66a0da2ca1f3c14132e2598f"),"operation":{"operationType":"OTHER"},"serial":"67ac96e6-0fb2-4e17-8d0f-b0718c7222ab","timestamp":NumberLong(1721817694466622603)},{"_id":ObjectId("66a0da2ca1f3c14132e2597f"),"operation":{"operationType":"CREATE"},"serial":"67ac96e6-0fb2-4e17-8d0f-b0718c7222ab","timestamp":NumberLong(1721817644466622603)}]

db.collection.aggregate([{"$match":{"operation.operationType":"DELETE"}},{"$sort":{"timestamp":1}},{"$group":{"_id":"$serial","wantedBoundaries":{"$push":{"$add":["$timestamp",NumberLong(1)]}}}},{"$project":{"wantedBoundaries":{"$concatArrays":["$wantedBoundaries",[NumberLong(0)]]}}},{"$project":{"wantedBoundaries":{"$sortArray":{"input":"$wantedBoundaries","sortBy":1}}}},{"$lookup":{"from":"collection","localField":"_id","foreignField":"serial","let":{"wantedBoundaries":"$wantedBoundaries"},"pipeline":[{"$bucket":{"groupBy":"$timestamp","boundaries":[0,1721817723495723671],"default":-1,"output":{"serial":{"$last":"$serial"},"count":{"$sum":1},"operations":{"$push":"$$ROOT"},"wantedBoundaries":{"$last":"$$wantedBoundaries"}}}}],"as":"test"}}])