Developer to Install and Configure Ad Server functions on Website

We are looking for a solution to manage our ads on our website.

The job scope includes recommending, installing, setting up the proposed ad server. Including setting up of the ads across existing and new pages of the website, For example, this page ( ---------- ) has no ads yet, but we are looking to add in ads in the template.

The proposed solution needs to be able to manage different campaigns for multiple advertisers. It must also be able to track campaign performance and provide detailed statistics such as impressions and clicks for exporting. The backend shouldn't be complicated as the end-users do not have deep technical knowledge.

As our website is custom-coded, we need the developer to also ensure that the functionality of the website is the same before and after the addition of the ad server.