I spent 2 weeks at work building a dashbord (not a feature but...) wich provided an overview of projects and tasks managed in redmine (Kanban tool) by using its API. After i finished it we started using it till my boss found out that it was completly "useless" for him - it had all the features he asked for! -.- ...
three days later the redmine server crashed and we changed the provider, nobody missed my dashboard and so it got abandoned :( sometimes i miss it, it looked fancy af and stuff!!
But at least i learned a lot of js and API stuff. I was verry new to js back then :)

Boss asked -> I deliver -> and *pooff* down the river it goes. seems like my tasks have not changed much since then.