kibana/x-pack/plugins/infra/server/utils
..
calculate_metric_interval.ts
create_afterkey_handler.ts
elasticsearch_runtime_types.ts
get_all_composite_data.ts
get_all_metrics_data.ts
get_interval_in_seconds.ts
README.md
request_context.ts
round_timestamp.ts
serialized_query.ts
typed_elasticsearch_mappings.ts
typed_search_strategy.ts

Utils should be data processing functions and other tools.... all in all utils is basicly everything that is not an adaptor, or presenter and yet too much to put in a lib.