As an Indian citizen, you require a visa to visit the United States. Indian citizens are not eligible for the Visa Waiver Program (which requires ESTA).
A business visa (B-1) allows you to come to the US temporarily (usually up to six months, often much less) for certain permitted business purposes, such as attending meetings or training. It does not allow you to work in the US at all, and you generally cannot receive any income from a US entity. The wait time for an appointment at the US Embassy in Berlin or Munich is currently 6-7 days.
If you don't qualify for a B-1 visa because you actually need to work in the United States, you will need an employment visa. There are several types of these, depending on your position and circumstances, and all require a fair amount of effort to secure, if you are even eligible (often months-years; if you qualify for an L-visa and your company pays through the nose, it can be a few weeks once the paperwork is done). For an employment visa, a US company must submit a petition on your behalf; they will generally hire an immigration lawyer to assist them with this.
If you're unsure what type of visa you need after reviewing the US State Department's information on visas, your company should consult a US immigration lawyer.