Address the task of efficiently searching for a specific item in a large online marketplace database using a linear search algorithm.

Algorithm: Linear Search

Analysis $($one page, excluding cover and references$)$: Delve into why linear search is applicable for this scenario, examine its time complexity in the context of online searches, and discuss how the chosen data structure affects its performance. Identify external factors that could influence the lower bound of this solution.

Please ensure that submission includes the following components:

Source code file$($s$)$ containing the program implementation.

A $1-$page paper $($excluding the cover and references$)$ explaining the program's purpose, the obstacles faced during its development, and the skills acquired.

The paper should also include screenshots showcasing the successful execution of the program.