DS160 Previous Employment related question

[Iamsharma]

I used to work for firm X as 'Systems Engineer', mainly handling Data Engineering along with other Software and Cloud tasks. After leaving X, I've switched jobs a couple of times, and I currently have a 'Software Engineer' offer from a US firm Y, through which I have an approved I-797B. The resume Y used for the petition process lists my title at X as 'Data Engineer'. I target Data Engineer and related roles, so I sometimes use that title on my resume to better align my work at X with job openings and to pass the ATS.

Now, filling out the DS160, I'm unsure whether to write 'Data Engineer' or 'Systems Engineer' for my role at X. The Experience Certificate from X says 'Systems Engineer.' The 'Software Engineer' offer from Y primarily requires Data Engineering and Cloud skills, among others, so I have the relevant skills.

Since I have an I-797B, I have to go through consular processing, so I am in India to get the visa and enter the US to start my work at Y. However, I am eligible for an H1B interview waiver based on the questionnaire the appointment website asks. Getting an appointment is hard in India, so I've booked a dropbox appointment. But I need advice on what job title for X I should mention on the DS-160.