You can still get to do interesting things, but the assembly is a bit more tricky. Here is a little board I designed for work recently. Dual ARM core SoC+FPGA, USB, dual 1000BASE-T Ethernet, 2GB ram (a million times more than my first computer!), multiple FLASH memories, truck-loads of I/O, plus power supplies of course. Resistors are mainly 0402 size, so 40x20mil. Track lengths are adjusted so groups of them have all the signals arrive at the same time. c (speed of light) can be a pain sometimes.
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So I am still having fun with computers 47 years later
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[edit] I should mention that reading somewhere north of 15000 pages of datasheets was involved in designing that board. Worked first time.