Strictly KISS. No electronics. Very simple. I mash and boil in a kettle on an induction plate (3500 w). I control fermentation temperature by moving my fermentors (plastic buckets) around to where the temperature is right. I can do that because I live in an old house with a cold cellar, and rooms with different, but stable temperatures.
I brew some 50-60 batches a year, normal batch size being 25 litres (6,5 gallons). I bottle all of it. Most of it will be German and British beer, but also some American IPA, pale ale and NEIPA. And some odd saison, cream ale or whatever happens to get dumped into my head. No sour beers. Very little strong beer. And no adding to the beer stuff that doesn't belong in there, like spices, fruit, vegetables and dead insects.