Hi, I can do the job in one to more days.
I'd played Asterisk for more than 7 years, and I'm familiar with dialplan, know how to setup dialpan to deal with database/LDAP/web-services/other-interfaces in Asterisk.
Depends on the complexity of the dialplan , the job can be done in one to more days.
* If the dialplan is not too complex, it can be done in one day (probably in hours).
* If the dialplan is complex, such as we need to setup external resources as the dependency of the destination dialplan, it could take more time.
You can see one of my Asterisk project in GitHub, search 'anti-fooling-hot-line' (no big deal, it's a just-for-fun project).
Best regards!