According to the JSON specification, JSON objects are unordered. So if you get the same ordering, it is entirely coincidental or an implementation detail of the underlying library. But you can not rely on ordering of the entries there since they are, by specification, not ordered.

You may want to considering using a list instead if the ordering is absolutely required.

By the way I had a problem where I had to get the json ordered.

I found out we can use Jason.decode(json_string, %{objects: :ordered_objects})

Why combine the data for the key into a string just to need a regex to separate it again. You can have a key like {count, key} in elixir maps.