Have you done any performance testing? Which are your slowest endpoints?
Do you have a run book for how to do the deployment from beginning to end, step by step.
What change control process do you need to go through with the client? Approval forms, signatures, scheduling etc.
what is your code coverage for unit testing? Should be above 80%
Has static code analysis been run, is the code of high quality? SAST.
Are there any DAST requirements / vulnerability testing requirements?
is the correct logging and monitoring in place to go live? If there are errors how will we troubleshoot them?
app dynamics? New relic? App insights?
are there health checks in place for your integration points? If an integration is down what does that mean for your system?
are all the test cases passing in qa? What % of failure are we on to go live with?
Any outstanding bugs / tech debt?
all documentation to support the system in place? Network diagrams, environment details, user names, urls, etc.
what is the roll back plan? How will the system be smoke tested once live? What other testing is required once live to confirm it’s all working? If it’s not working at what point to you roll back / fail / abort the go live?
if going live is after hours have you booked and communicated the time with your team?