I worked in small company (50-100 employees) and lead team of 7 people before. After company went down, I joined as IC in big corps. Few things mentioned below might not be relevant to your position. But adding them for every one. Not all orgs are same, so take this with pinch of salt.
- Relax, don't boil the ocean. (This is first advice given to me by one of the director after raising concerns over dev practices being followed)
- Learn presentation skills. Charts are important. Executives don't understand technical language but only charts.
- Stay humble but be political. Avoid heated arguments. Give logical choices to people and let them choose instead of proving them wrong. Make sure to get all discussions on mail. So if later blame game starts, you will be saved.
- In such orgs, some folk stays for decades. They don't care about product or team. Deal carefully with them. But then again you can find some real gems with decades of specialist experience. Learn from them as much as possible.
- Learn proprietary technologies. Most of time such techs are not available for individuals or very pricy.
- Get certifications. Big corps provide very expensive certifications with huge discounts. (But before working on them make sure there arn't any traps. E.g. In my org, you had to stay for atleast a year after finishing certifications or pay back)
- Understand KPI well. (e.g. In startup, you may get appraisal on working hard in weekends and shipping. But in megacorps, that won't happen. You may get some praise but not appraisal)
- If you want recognition, try to conduct department wide technical sessions. People will respect you in (those never ending) meetings.
- Don't invest your emotions in projects. Sometimes they get scrapped quarterly.
- Welcome to world of VMs. Organizations are tuned for operations not for engineering. (I miss my Linux)
- Even though your performance is good, you can get canned. Layoffs are done based on budget not on performance. Keep an eye on Gartner index. Also manager plays key role in almost all decisions. So think once before messing with him/her.
- And last but not least. Don't go in comfort zone. Always keep an eye on market & opportunities.