I still use Ada daily for my personal projects after having used it at work. I find it compliments my thinking patterns well. My only gripe with it is that they ate too much of their own dog food at AdaCore and now it can be hard to install Ada and gprbuild (due to a circular dependency). Plus gprc stole libgpr and broke some stuff too.
Sadly front end, like “High Level” is a very relative term. For example, in compiler design, the bit that parses code is called the “front end” since the “back end” is what emits machine code. I think that’s what they mean here, the “front end” that understands D3D8 code has been added, presumably there is also a “back end” that converts the parsed/analyzed D3D8 code into valid opcodes for consumption by GPU/CPUs.
In the other direction, a UI/UX is sometimes called a “back end” when it is part of a more complex embedded project where physical controls are the “front end”.