How can we leverage the capabilities of Outsystems platform in an e-commerce site?
The site is already built and stable as per legacy implementation. We would like to know how can we use Outsystems to plugin in our present solution.
To get help on this you really need to define 'plug-in' better within your application. I'll assume that you want Outsystems to be the front-end, the part the public sees, and call the backend e-commerce code when appropriate. If the e-commerce code exposes a standard way of calling it (Web Service, REST, etc.) then it will be extremely easy. If the e-commerce code requires an interface using a .Net or Java API call, it's still very doable, just more difficult.
Describe 'plug-in' better and I'm sure you'll get more help.