First and foremost, good cryptocurrency brokerage software has strong encryption, two-factor authentication, KYC, KYT, and AML procedures in place, and secure storage for user funds.
User management capabilities, including KYC/AML verification and account management, are equally important. The software should also provide digital crypto wallet management, reporting and analytics, customization options, and scalability.
Finally, comprehensive documentation that guides you through the software's features and functionality should be one of many considerations.