Here's an idea that might work if your org is doing github issues (or some other git host with similar feature). Let's assume you have backend code spitting o

Here's an idea that might work if your org is doing github issues (or some other git host with similar feature). Let's assume you have backend code spitting out the frontend code which still needs to be loaded as a page in a browser to let javascript do its thing before you have the actual DOM you want to inspect and comment on. If the backend is producing your HTML fully formed -- not bootstrapped further using javascript that is -- then you might be able to get away with telling your backend to produce a static version of your site, check that into git, and then people can comment on the individual lines on github by clicking the line numbers to reference that line in a new issue.