in the process of doing
Indicates that an action is in progress at the moment of speaking or at a referenced time.
This pattern emphasizes that the action is currently ongoing, often with the nuance that it is happening right now or right at the moment something else occurs. It is similar to the present progressive, but adds a focus on the 'point in time' aspect. You can use it to say what you are doing at the moment, or to describe that someone was in the middle of doing something when another event happened.
It is commonly used in everyday conversation. For example, if someone calls you, you might say '今、ご飯を食べているところです' to explain why you cannot talk long. It also appears in set phrases like 'ちょうど今から出かけるところです' meaning 'I am just about to leave' (though 'ところ' can also indicate a point just before an action).
Note that the pattern is not used with verbs that describe states (like いる, ある, わかる) because those are not actions with a duration.