List of free optimization stuff for developerππ½
If you're looking for all programming tools around optimization (not just free). Check this page List of optimization Programming Tools

Autocompress: Image optimization for Bitbucket
Optimizes the images in your Bitbucket repositories
Tag: image, optimization, compression, static assets, serverless, performance, asset, hosting-static, storage
Unlimited for public repos. 14-day trial for private repos (enough to compress all your images)
Open Source