[JavierRibaldelRio]

├── logger.rs              facade: re-exports CsvFile, TextFile, the JSON API and Error; module docs
└── logger/
    ├── README.md          module doc: API, guarantees, features and what's out of scope
    ├── error.rs           Error: one variant per failure, every one naming its file
    ├── target.rs          private: label, poisoning, explicit flush, courtesy flush on Drop
    ├── csv.rs             CsvFile + Row: header as contract, whole row or nothing, RFC 4180 quoting
    ├── text.rs            TextFile: one line verbatim, same vocabulary as CsvFile
    ├── json.rs            write_json/read_json and JsonDocument: atomic save via .tmp + rename
    ├── files.rs           feature files: copy/move/remove/size, creating dirs and naming both paths
    │   └── error.rs       files' own Error, carrying source and destination
    └── host.rs            feature host: HostInfo::collect() and open_file_limit(), nothing fails

The logger is an utility module, is not relly related to the backend, but will be useful.

Is better than use fs each time because custom errors are worthy while working with a decent amount of files

[pminmic]

Looks ok to me