Besides the historic use of BJTs in TTL logic, there is an inherent problem with hFE Max/min ratios in production. Some companies such as ROHM specialize in binned BJTs with low hFE ratios and essentially lead the industry in digital transistor switches.
Naturally, BJTs have been used for many applications such as RF, high-speed analog switches using common base mode with many for multiplexing channels or level shifters and high voltage switches with FET inputs called IGBTs.
Early Scopes and TVs used BJTs for everything from power supplies, voltage regulators, video clamps, video DACs, high-speed SRAM, and hundreds more applications.
You can review ROHM's digital transistor options here.
Method of finding solutions
Socratic search method of using coarse then finer search and answers in a web search.
e.g. web search
- = BJT applications analog
- = BJT applications analog RF
- = BJT applications Automotive
W. K. C. Guthrie in The Greek Philosophers sees it as an error to regard the Socratic method as a means by which one seeks the answer to a problem, or knowledge. Guthrie claims that the Socratic method actually aims to demonstrate one's ignorance. Socrates, unlike the Sophists, did believe that knowledge was possible, but believed that the first step to knowledge was recognition of one's ignorance. Guthrie writes, "[Socrates] was accustomed to say that he did not himself know anything, and that the only way in which he was wiser than other men was that he was conscious of his own ignorance, while they were not. The essence of the Socratic method is to convince the interlocutor that whereas he thought he knew something, in fact, he does not."
I conclude that this Socratic (web search) Method should be better called the Guthrie Method. Assume you know nothing about the answer. Whereas this site uses experts who know something about the answer but the question needs better scope details prompted by comments. (Socratic Method).
There is an online electronic simulator written by a programmer named FALSTAD. You will find lots of basic designs built in to simulate.
It can do FFT and users can choose hFE , but it is constant not nonlinear when saturated to 10% of hFE.