I think it's best to give an example. In one of the companies I worked for, it was always an uphill battle to get our decisions approved. One of our wins was establishing an interview process with our customer relations department, they would provide people, we would interview them (not ideal, but that's what we had). And in those interviews we learned a lot, especially about the order in which our features were being developed. Most of the features they asked, were already planned, but in a different priority, so the most requested features would come after other features. That actually helped us to develop those requested features more deeply, since we had a little bit more time with the prioritization. We also made sure to ask about those features that they used in our competitors, and how they used it, so we could map out the interaction flow better. To summarize, the result was a better preparation stage, with better mapped flows, mapped expectations from the users and context.

I would note the most recent experience, which was changing squads at Clara. I was in the Acquisition squad, which dealt with growth and user engagement to the Payments BR squad, which was developing a digital account for BR, there I dealt with financial products and payments, and we were developing Pix for the digital account (for those not in BR, Pix is a payment method controlled by our Central Bank, really quick, easy to use and safe, and everyone uses it), which would be a real game changer for the company. Unfortunately I didn’t get to see the end of this project, but it was approved by the founders and it was looking like a smooth hand off. I also worked on products that brought a lot of value to our customers, including a solution to bring more assets under management to the company in under 15 days.

With "internal clients'' or stakeholders. In my last job, there was a problem with company-wide consistency in design, since processes were confusing and not well defined, everyone tended to follow or create their own, so that can lead to many inconsistencies, not only visually, but also on experience and interactions. That made the CTO centralize all approval flows on him, someone with "particular" design notions. And my highest moment there was having my Pix prototype (which you can take a look at the link I provided) approved, with minimal pushback. That was a gigantic team effort and me and the PM worked closely and held several rounds of testing and discussion with the rest of the design team and the product owners, so we compiled all feedback, discusses finer points and reached conclusions that were enough to create a proposal in  the form of a prototype, of course that didn't end it there, we would still need to go through several rounds of testing and further refinement, but this short story just serves to illustrate how dealing with feedback is an integral part of any designer's work, and I have dealt with it in the past.

Yeah, if this page was not proof enough. I lived in the US for a year in 2017, also I've been working in English heavy environments since my first job. My last job at Clara (a Mexican company) had English as it's main language, since it not only had Mexican employees, but also people from all over LATAM, including Brazil, so English was the common denominator and used freely. I have experience in presenting projects and arguments in English, I'm no stranger in defending my points and expanding discussions in that language.