Q: My OPT will end in mid Feb and my grace period ends in April. Can I continue to work for my employer?
A: Technically, if you can submit the H-1B package prior to the end date of your grace period, you can stay in the U.S. while waiting for the H-1B result. However, you shall stop working for anyone during this period.
Since this year (2020), USCIS implemented a registration step, and only selected ones are eligible to submit their H-1B packages, the uncertainty of timeline and others has increased. Therefore, if you are in similar situations, you can choose to go outside the U.S. first and apply for H-1B visa through consular processing; or it is recommended not to use your grace period (such as extend/change status to another type of visa first).
Please feel free to share your thoughts and questions below.