Please give detailed explanation and information to all three requirements below which start with "The WDC should have....".
We are a US emerging internet entrepreneur company who is seeking for one of top Indian Web Development Company (WDC) to work on our large scale global web projects. We want to outsource everything (A to Z) from this top web development company: Back-end development, front-end development, server management, mobile app development.
+ The WDC should have the proof that they are one of the top Indian WDC with solid reputation with their top references.
+ The WDC should have solid references for Payment Processing web projects (PSP, Payment Gateway, Credit Card Payment Processing), Complex Algorithm global web projects; preferably Advertising Platforms, preferably Computer Vision web apps.
+ The WDC should have Senior Software Architects, Senior Software Engineers, Senior Software Developers, Senior Server Specialists.
+ Solid practical knowledge on real-time, large-scale web application system design, implementation and scaling.
+ Advanced Knowledge of Backend Technologies / Programming Languages & Frameworks:
PHP, Mean Stack, RoR, Python
+ RESTful API Design & Implementation
+ Advanced Web Crawling/Scraping.
+ Large-scale Database Design, Database Performance Turing, SQL Query Optimization.
+ Familiar with High availability, Scale-out, Replication, Distributed systems and cache techniques.
+ Web Application Security, Unix/Linux Knowledge, Control Version Systems (Git).