CS/EE here. Malfunction still leads to dragons overall. The problems of sequential logic looping to itself and talking to the outside world under various conditions include (but aren't limited to): getting predictable initialization, predictable durability, matching input impedance, and creating chips with characterizable and reliable setup/hold/delay/etc. times.
These days, I leave chip design to chip designers and barely do silly things like create seven (7) total 4 pin to 3 pin Arduino PWM fan controllers with MOSFETs, MOSFET protection and noise reduction circuitry. See, I have to keep the fans fed with over 4 volts so the tach signal continues and the storage array's BMC doesn't freak out. (The fans characteristics I needed aren't/weren't available in 4 pin PWM.) I try not shock myself like ElectroBOOM or release too much magic smoke from gear or vintage gear that might not be replaceable.
These days, I leave chip design to chip designers and barely do silly things like create seven (7) total 4 pin to 3 pin Arduino PWM fan controllers with MOSFETs, MOSFET protection and noise reduction circuitry. See, I have to keep the fans fed with over 4 volts so the tach signal continues and the storage array's BMC doesn't freak out. (The fans characteristics I needed aren't/weren't available in 4 pin PWM.) I try not shock myself like ElectroBOOM or release too much magic smoke from gear or vintage gear that might not be replaceable.