I need a HTML web development agency

We are digital marketing CRO company, we run AB test campaigns on our client's website. Our campaigns are exit pop- up, marketing emails, HTML snippet inserts(replacement of CTA, search bar highlight, porduct description changes, sticky navigation bar, highligliting reviews, best sellers, product recommendation), Email optin pop up, lead generation pop up, hero image change, Survey etc. Here we want to outsource the HTML development and UI testing of campaigns. On a monthly basis the demand is for 600 campaigns development which will be spread across the month(you need to have 15-20 HTML dev or must be willing to expand the team and should have a ready team to 6 Dev dedicated to us) we will give the dev assets, designer assets and campaign requirement document. Each campaign must be delivered in 3 days with one round of testing, we have a in-house testing team who would retest the campaign if any bugs are found this must be fixed in 2 working hours. KPI On time delivery 95% Bugs per campaign 2 Payment will be made on a monthly basis upon invoice verification Penalty will be charged for under performance Incentive will be given for better performance