There are a number of ways to filter specific users out of Google Analytics:

• you could filter them out by their IP addresses
• if they are using dynamic IPs, you could ask them to install the following GA opt-out plugin https://tools.google.com/dlpage/gaoptout . It is compatible with Chrome, Internet Explorer 8-11, Safari, Firefox and Opera. The disadvantage is that this plugin would also affect all other websites from counting your devs as visitors. It blocks Google Analytics for all websites, not just for your website. I do not think it is a real problem, but it does provide some undesired side effects. So below is another solution
• create a webpage on your site that would set a "disable-analytics" cookie in users browser. Make all your developers visit that page. Server side, render GA javascript only of there is NO blocking "disable-analytics" cookie in request. The cookie name is irrelevant, it could be "block-google-analytics" etc

You can create an advanced filter (Analytics Settings > Filter Manager > Add New Filter)

Here's a screenshot of the filter you'd have for your first example.

In the second example, you'd replace the form fields with

/task=(.*);taskupdates and /task=;taskupdates