save-load-systems

Persistence engineering for Unity and C# games - what to save vs derive, save data models as plain serialisable classes, stable unique ids for saveable objects, serialisation choices (JsonUtility, Newtonsoft JSON, binary), Application.persistentDataPath, atomic writes with backups, versioning and migrations, corruption handling and validation, checksums vs encryption, autosave and checkpoint policy, slots with metadata and thumbnails, cloud saves, async IO, saving during scene transitions, PlayerPrefs for small settings, and round-trip and migration testing. Load when designing save files, adding saveable state, migrating save formats, or debugging lost or corrupt saves.