Business Visa - B1

I have attended B1 Visa on 10th Oct 2019 in Chennai, outcome - not approved.

The questions as follows-

1. Good Morning & Passport Please?

Good Morning with a smile & given a Passport.

He took some time to review my DS -160

Which city you're traveling

Teach lead., Fumble.. then said Team lead..

What is your role?

Washington DC

how long you stay

1 week.

Which company your working

I am an associate with YYYY company.

what this company do

providing services to the client on the software..

How long your working..

since 1 year I am working with this company

Total how many companies you work

5 companies..

what was your longest work experience in these companies

3 Years.

why you're changing your company.

for better opportunities.

Do you have an invitation letter

Yes, provided..

Why your company choose you for this trip

I am most senior in the team and lead this team and having good work experience on what we support to the client.

Sorry.. We have not approve your travel.. given 214(b) form..

I am having an interview on 30th Jan 2020 for the second time..

Please could you help to present my self to get approval?

This time my company is not providing an invitation letter for B1 Visa.. is it fine attending interview without an invitation letter