ATG eCommerce

ATG is a leading provider of eCommerce software and related on demand commerce optimization applicaiton, and headquartered in Cambridge,MA  
It's the framework which comes up when ther is eCommerce implementation for high scale companies not used for small scal comanies as implementation time and resource cost will be high.Some of the Companies I know which uses ATG are Wallmart,AT&T,Best Buy,J.C Penney,Tesco , Vodafone, Lexixnexis, Verizonand T Mobile. IN 2015 ,Oracle released the Oracle Commerce Cloude a next generation ,cloud-based e-commerce platform.

Most of the online shopping application are migrating to Oracle ATG for the best perfomance of their website and for the customer satisfaction who visits to the website for online shopping.

For Developer respective,
Is's critical to grasp the ATG module like as ORM,Droplet for few,Shopping Cart, Personalization ,Catloge management.There are lots of modules like as BCC,ACC and CSS which will take good amount of time to good knowledge on those.I have explain some of critical points bellow.

ATG Nucleus
ATG Configuration Layering
ATG Config Path
ATG Component Scopes And Rules
ATG Custom Droplet
ATG Implicitly Modules
ATG Maintain Profile for Guest or Anonymous User
ATG Scenarios and Targeters Different
ATG Application Between Session
ATG Custom Price Engine
ATG Custom Servlet Pipeline
ATG CartModifierFromHandler And ShoppingCartfromHandler DIfference
ATG Repository API
ATG Repository ,Item descriptor properties
ATG Commerce Order, Shipping, Payment Status Code
ATG Repository Basic Description
ATG Repository web services
ATG  Installation And Configuration guide 10.1
ATG Configuration With Eclipse 
ATG Repository Caching
ATG Pricing Calculator 

References

Oracle and ATG