Firstly, you should show some of your work. If it's not work you've done for a client then it should be work you've done at home. Secondly, unless you're showing your work to someone who understands and also has the time to look through your code, you will need a nice UI to go with it. It adds that Jazz Factor to your work. You can then explain that you did the back end to that UI. Finally, There are great sites out there to display you work. I'm going to recommend one (because it's mine :)) codeenv.com allows you to share and show off backend work. You can share your work in an environment which allows users to instantly click and run your code. There are other websites of course which allow you to do similar stuff but I won't recommend them purely out of bias