Writing to a nested JSON array in Azure data factory

Question

I am trying to convert data from a CSV file to JSON with nested array. I want the following source data

JobId   JobDate  Skill     SkillCluster
1   20122019     100        SkillTest1
1   20122019     200        SkillTest2
1   20122019     300        SkillTest3
2   21122019     1200       SkillTest21
2   21122019     2200       SkillTest22
2   21122019     3200       SkillTest23

to be converted into below JSON using Azure Data Factory.

[{
   "JobId": 1,
   "JobDate": "20122019",
   "Skills":[{
   "Skill":100,
   "SkillCluster": "SkillTest1"
   },
   {
   "Skill":200,
   "SkillCluster": "SkillTest2"
   },
   {
   "Skill":300,
   "SkillCluster": "SkillTest3"
   }]
 },
{
   "JobId": 2,
   "JobDate": "2112019",
   "Skills":[{
   "Skill":1200,
   "SkillCluster": "SkillTest21"
   },
   {
   "Skill":2200,
   "SkillCluster": "SkillTest22"
   },
   {
   "Skill":3200,
   "SkillCluster": "SkillTest23"
   }]
 }]

I can see JSON array can be read and flatted but I am trying to achieve the reverse of it."