Back-end and front-end programmer on PHP+ExtJS

Development and writing of new modules (implementation of new functionality) for the collaboration system on ExtJS5+php+mysql. Among the already implemented opportunities there are contacts, tasks, calendar, projects, service desk and much more. There is no complete written TZ, the customer will work "interface designer", he will organize and dispatch the work of remote freelancers, issue short operational TK and take the work. We plan to attract 3 remote freelancers with full-time employment. We also consider mixed work in the staff-programmer/freelancer groups. The implementation period is about six months, the related project on the same technical basis is designed for 2 years.

A test task will be issued, which will be evaluated by a remote independent freelancer for the quality of the code and the level of capabilities of the programmer. Important evaluation criteria:

Follow the modern style of programming - ORM, MVC, data separation, logic and design.
Maximum abstraction from the language and technical means used, for example, from the type of DBMS used.
Code modularity and reuse capabilities, extensible core designs.
Compact code and its speed
Multiversion of all changes (Git & Subversion)
Maximum use of native capabilities of common components, without tricks, hacks, "crutches" and other things.
Optional, but desirable, is to reasonably document the written code and provide a primitive API to the written. If the applicant has such skills, please demonstrate them.