Cypress.io is an alternative end-to-end test framework that does NOT use Selenium. Since I've only evaluated this tool as a possible solution, my estimation of its performance against Protractor is incomplete. However, if you and your team are looking for automation solutions …
SoapUI Open Source is free, which is good for light use or simple things here and there. There is a Pro version that makes things more user-friendly. I also like that custom code can also be used for doing more complicated tasks. I like that SoapUI can have a process/flow …
If you are making system upgrade project and you have existing system working and you want to imitate messages that are going in production but without making any data loads or switch it’s very suitable and convenient software. It serves well in manual test scenarios but wouldn’t be as good in case of mass tests.
Cypress.io is an alternative end-to-end test framework that does NOT use Selenium. Since I've only evaluated this tool as a possible solution, my estimation of its performance against Protractor is incomplete. However, if you and your team are looking for automation solutions outside of the Selenium scope, then Cypress.io may be a good fit given the problems you're trying to solve.
SoapUI Open Source is free, which is good for light use or simple things here and there. There is a Pro version that makes things more user-friendly. I also like that custom code can also be used for doing more complicated tasks. I like that SoapUI can have a process/flow (conditional/loop/waits/etc.) set up for scripting purposes, which is good for beginners and light users. However, I think the user interface has room for improvement.