I need help with high level PHP, MySQL, APIs, Wordpress programming

General information for the website: Custom application
Description of requirements/features: We provide our clients with a Late deals system, which is currently hosted on their own web site (Wordpress multisite). We are moving this to a centralised server and opening it up to non web site clients.
We are looking for someone that can work on their own initiative from tasks which may not have detailed information and be accepting of last minute changes to tasks.
The centralised server is running Wordpress multisite so that clients can have a unique sub-domain.
This is an ongoing role, with much of the initial setup already done.
We just don't have enough time to get it finished off as quick as we would like.
There will be a requirement for further development of the system.

The 2nd system we need help with invloves interaction with Social APIs - Facebook, Google+ & Twitter to start with.
The basic system is built on Yii2 framework.
There will be a loyalty scheme so users can track online what their points are. Points will be added for various activities and redeemed against services provided by our clients.
This also involves free wifi on the clients premises which involves teh user posting to a social network to gain access. This is linked to the website so that users gain points for wifi login etc.
The APs are already in place in about 15 locations.
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