---

id: development title: Practical Example App sidebar_label: Development workflow slug: /development-workflow

REPL driven development with GX

Complex system configurations are prone to errors. GX was developed to support REPL driven configuration with following workflow:

1. Fire-up an application REPL
2. Create/update components
3. Create/update config file(s) or just define a config in source code
4. Load and register a system(s)
5. Try to launch a system(s) by sending a startup signal
6. Examine failures (if any)
7. Send a stop signal to clear started resources such as HTTP server or a database pool
8. Go to step 2
9. Repeat

Failure examination

GX's system namespace has two main functions to get failures:

• (gx.system/failures <system-name>) - returns a list of failures as a maps
• (gx.system/failures-humanized <system-name>) - returns a list of human readable stringified failures