Hi Suraj,
Most complete and robust solutions actually use a combination of declarative and programmatic solutions.
Developers should understand how to develop using both declarative and programmatic features of Salesforce.com.
Always try to use declarative “or” Point-And-Click approach first before writing any code.I will explain you with the help of a scenario.Let’s say you need to Perform a task if (no of opportunities in Accounts = 3).You can split this up.With the help of Rollup Summary ,you can count no of opportunities(instead of writing a trigger) & rest you can do it with the help of code.
Thanks