Mongo queries just for reference

mongo.md

db.people.aggregate([
{
    $lookup : {
        from :"companies",
        localField:"company_id",
        foreignField:"_id",
        as : "companys"
    }
},
{
    $unwind : {
        path : "$companys"
    }
},
{
    $project : {
        first_name : 1,
        last_name : 1,
        job : 1,
        company : "$companys.name",
        sector : "$companys.sector",
        _id : 0
    }
},
{
    $sort : {
        job : 1,
        sector : 1,
        last_name : 1,
        first_name : 1
    }
},
{
    $skip : 99
}
])