Thus far the most interesting factoid I learned from reading about this is that Venus had a hospitable atmosphere only 750M years ago!

So, if there is life, it may be leftovers that survived a billion years ago or so. Pretty rad!

Or it may just be a freakish Russian expat that hitch-hiked on Venera, mutated to survive there, and has now totally colonized the atmosphere...

In support of the spacecraft-Earth-to-Venus-transfer-of-life scenario is evidence that viable fungi and bacteria not only survived heat-treatment sterilization of spacecraft (La Duc et al. 2014; Venkateswaran et al. 2012; Puleo et al. 1977) but may have survived the journey from Earth to Mars, as successive photos taken months apart depict what appears to be masses of fungal-bacterial organisms growing on the NASA’s Mars rovers Curiosity and Opportunity (Joseph 2018; Joseph et al. 2019).

Source : Life on Venus and the interplanetary transfer of biota from Earth

It's possible, in theory, but highly unlikely. If a terran extremophile (which is not normally found outside its home habitat) just happened to somehow be on the Russian probe it would have to survive launch, transit (at very low temperatures), and re-entry into the Venusian atmosphere. The space shuttle exterior is rated to 1510° C; unmanned probes (Orion, Galileo, Stardust, etc) have reported atmospheric entry temperatures exceeding 2000° C. The hottest temperature a hyperthermophile has survived is 130° C, so the exterior of the probe would almost certainly be sterile. It's far more likely that a microbe of Venusian origin managed to evolve and survive within the more temperate parts of the upper atmosphere than that a terran microbe made the journey successfully.

The author of that article is a pseudoscience-promoting crank who thinks that he saw mushrooms growing in the photos taken on Venus (and apparently believes he's seen them on Mars too). A blobby shape in a photograph is not evidence.

Earth has microbes that spend their entire lives in our upper atmosphere. It's possible, if life evolved on Venus during it's habitable phase, that such organisms could still exist, being the only type of life that survived the runaway greenhouse effect.

You know, I actually wrote the first line as a joke. Out of curiosity, I did a literature search to see if anyone had actually written a paper about the idea - I found (a very bad) one, which you see there. I have no idea who the author is, but the quality of the paper speaks for itself. There's no need to resort to ad-hominem attacks. Your opinion of him is not at all correlated to the quality of the evidence presented, which is demonstrably poor.

So yes, of course it's ludicrously unlikely that microbes survived the transit to Venus. But recognize also that we have very little way of objectively calculating what the probability of life evolving on Venus even is. Yes, it's fantastic to suggest that microbes survived a journey from earth, but it's also fantastically unlikely that life evolved anywhere. What you have, now, is a ratio of two unknown, very small numbers whose uncertainty bounds admit both the possibility that one or the other of these two scenarios is wildly more probably than the other. In science, this boils down to the only valid conclusion, which is that at present we do not have enough evidence to support either conclusion. We barely have evidence that life even exists at all on Venus.

All this to say that a venomous rebuttal of any position, at this point, is premature and really uncalled for. We don't have to dig in and pick sides here - it's not that important of a fight, dude. It was just meant to be fun conversation.