Deadlines aren't always meant to be made, depends on who's doing the estimate and how much the scope changes along the way.
Some managers also setup impossible deadlines to try to squeeze all the productivity they can out of their team.
But you can work on improving meeting deadlines or raising a flag early on with your manager that you need to bump out a deadline a couple days. He'll appreciate hearing it earlier rather than the day it's planned to be completed.
If there is a topic you're curious about set aside a couple hours in the evening to research it and play around with it. Run through some dev ops tutorials.
As you do more and more projects you'll get a feel for how the design UI/UX should be. As a backend engineer I would expect you're not doing much design. But for mocking things up use a framework like bootstrap or one your team uses for projects.
Try to learn from senior developers around you.
Start doing some side projects at home. Sometimes the most learning occurs trying to build an application you are interested in for your own use instead of following a todo list tutorial.
Pick topics you are interested in. Google some tutorials. Don't just watch them or read them. Dig in and do them, extend them, take them beyond where the tutorial stops.
Get involved/netowrk with forums, user groups, bloggers and podcasters who develop in your language creating similar things.
Check if your company sends employees to conferences.
Development is definitely a continued learning experience.