Symfony's configuration system has improved *a lot* in recent years. Version 4.2
brings a lot of minor improvements that all together give an even better developer
experience. Let's step back and look at how we can tackle all of the
most common problems using the new approaches! This will include tricks for
configuring services as *easily* as possible, handling different environment
configuration and the hugely important topic of environment variables and secrets.
Best of all, we'll discuss some strategies to migrate your existing apps so you're
never going to be left behind.