Improvements and bug fixes in the online store

Improvements to the correction of errors in the online store.
Correction of errors in the layout, in the work of the personal account.
Refinement, installation and configuration of delivery modules.
The store operates on 1C-Bitrix.
The project with layouts is located projects.invisionapp.com
We consider a specialist with experience:
-Deep knowledge of HTML5, CSS3, experience of adaptive layout
-Experience in developing cross-browser web applications with asynchronous client/server interaction (JSON, AJAX, WebSocket)
-Experience debugging JS code (performance, memory leaks, etc)
-PHP7.0
-Experience in designing relational databases (MySQL, PostgreSQL), good knowledge of SQL and the ability to optimize SQL queries
-Understanding OOP and design patterns, following the principles of SOLID and DRY
-Live completed projects on Bitrix
We need a specialist who understands what needs to be done, and not waiting for stories on how to do it.