A field containing `"{\"name\":\"Alice\"}"` isn't broken — it's JSON stored as a string, inside a JSON document, a deliberate pattern in logging systems, GraphQL, and webhook relays. Here's how to recognize this pattern by its escaped quotes, why it requires two separate parsing steps, and how to tell when it's a legitimate design choice versus an unnecessary double-stringification bug.
JSON Patch (RFC 6902) sends a list of operations (add, remove, replace, test) to modify a resource atomically. JSON Merge Patch (RFC 7396) uses a simpler merge rule. Here's both standards with examples, JSON Pointer path syntax, JSON Path for querying, and why the `test` operation enables optimistic concurrency.
Python's None vs JSON null, JavaScript's integer precision limit at 2^53, Go's strict struct tags, and Ruby's symbolize_names security concern are real production pitfalls. Here's the JSON parsing edge cases in each major language and how they cause bugs at API boundaries.
Double-encoded JSON — JSON strings where objects were expected — happens when serialisation runs twice at different layers. Here's how it happens, how to detect it, how to fix it programmatically, and what the common Unicode escape sequences mean.
Learn what causes JSON to become escaped or double-encoded, how to recognise it, and how to use a free JSON unescape tool to clean up messy JSON from logs, APIs, and databases instantly.
