The idea would be to allow users to create fields dynamically at runtime, with a name also computed at runtime, as long as these fields match a "template" defined during bootstrap.

The “field templates” would be defined in a bridge's bind() method. The template to use would be deduced from the field name at runtime, both when indexing and when querying.

Implement only one way to match, for a start: “match” with glob pattern (“*_str”, etc.). Do not even implement "match by data type".

See https://www.elastic.co/guide/en/elasticsearch/reference/current/dynamic-mapping.html