At a previous job, the PM for another team often asked me to join some of their meetings — her engineers were shit at talking to non-technical people, so, for critical meetings, she asked me to join to serve as an interpreter of sorts. That's soft skills at work.
Talking to stakeholders and understanding what they need? Soft skills. Understanding the different between important and urgent? Soft skills. Being able to assess a candidate during an interview? Soft skills. Navigating cultural differences when you have offices or suppliers abroad? Soft skills.
I'd go as far as to say that the single biggest difference between a junior and a senior engineer is how well developed their soft skills are.