In my company we have recently received a new hire that is specializing in automating testing, which is a part of what we do but it is not our core business. I specialized at university in the field of our core business and I have been working in my field for the past 2 years, I am well aware of my limitations and the bounds of my knowledge.

The new hire has at most read 1-2 courses in the field and I reckon he is of the same age as I and he has not worked in this field before.

The problem I have with him is that is rude, he is constantly critizing my knowledge in different fields and today he explained what he was working on and started to explain some of the most basic parts of my field. Constantly asking if I understood what he was talking about. I answered politely, and refrained from giving him the pleasure of a sour remark but I grow tired of his antics. I have told him that I know well of what he is trying to lecture me on, but he continues to explain as if I had no previous knowledge of the subject.

When he arrived I gave him a warm welcome and helped him get sorted, but I have limited my input to when he is in the wrong or when asked to come with input. I do not back talk him and/or say anything bad about him.

However,I fear that he might be trying to backstab me with the boss, he has tried once already and I am starting to sense that the environment between us is growing toxic.

What can I do to protect myself? And what can I do to improve the relation?