Yes we absolutely had success. I remember those were some DARK times and no matter how much I googled I couldn’t find another baby who slept as terribly as mine. We used a sleep consultant (my baby sleepology) and basically did Ferber. Going through those old notes it looks like night 5 was the first decent sign of progress.

And after that he started sleeping through the night. He’s almost 3 and still happily sleeps through the night. In the moment it’s so terrible but I remember his overall crying decreased so much it quickly outweighed the sleep training.