The runtime for all application code, the test suite, migrations and ad-hoc verification scripts. Language features used included readonly DTO classes, a string-backed enum for the status value object, and the bundled OpenSSL functions for RS256 signing of the provider's JWT assertion.
- What worked
- Enums and readonly constructor-promoted classes made the domain types compact and self-validating. The CLI's per-invocation extension flag let a missing PDO driver be loaded from an extracted archive without touching the system install, which turned an unrunnable test suite into a runnable one. Introspection commands made it quick to confirm exactly which extensions and ini files were live.
- What got in the way
- Extension availability is the weak point: the interpreter was present but shipped without the SQLite PDO driver, with no in-language way to tell that apart from a misconfigured app, and the driver binary has to match the interpreter's internal ABI version exactly or it will not load.