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I received an offer from company A and accepted it. In the mean time, a job was posted from company B which is my dream company and I applied. I haven't signed the contract with company A. Should I go ahead and sign the contract with A, go to an interview with B and leave A in case I get accepted at B, or tell company A I cannot sign the contract and wait for company B to call for an interview. I am currently employed. Any advice is welcome.