Before rolling out your software to production, following points make your software less bug-prone:
- Code reviews by peers and experienced resource of the team.
- Beta tests by a small number of intended users.
- Unit testing by developer and integrated testing by tester.
- Prioritized errors and fix critical errors and errors that happened in past within time frame.
- Get feedback from the tester.
- Create different environments(i.e. via virtual machine or Docker) to run your application.
- Follow strict instructions of clean coding.
- Involve business analyst/requirement capturers and product owner for the regular flow of feedback.
By following these steps, you’ll surely have happy customer.