What type of system does the state of Texas use to hire and/or promote public employees?

Civil service system

Explanation:

Texas adopted the civil service, a system of employment that hires and promote public employees (in the Police and Fire departments) based on merit. Over hundred thousand applications are received on a yearly basis which are usually being evaluated against over 2,300 positions.

Apart from direct employee hire by the city departments, the Texas civil service system provides guidelines for recruitment and verifies employment exams that would be taken during the process. They also provide steps to handle appeals on termination and promotion of internal staff.