Database

[{"_id":ObjectId("5ff6335c1570ba63ca5ac21e"),"requirements":[{"description":"Bachelor of Science required for this blah blah blah","code":"ABC"},{"description":"Also much experience in JavaScript blah","code":"XYZ"}]},{"_id":ObjectId("5ff6335b1570ba63ca5abefb"),"requirements":[{"description":"Master of Arts WANTED NOW!","code":"TTT"},{"description":"5+ experience required in C++","code":"QQQ"}]}]

Query

db.collection.aggregate([{$addFields:{score:{$reduce:{input:"$requirements.description",initialValue:0,in:{$cond:[{$eq:[{$regexMatch:{input:"$$this",regex:"blah blah blah"}},true]},50,"$$value"]}}}}}])

Result