The combination of DAST (Dynamic Application Security Testing) and SAST (Static Application Security Testing) would meet the developers' requirements. DAST is used for runtime testing, capable of simulating attacks like SQL injection and reflected XSS, which fulfills the first requirement. SAST analyzes the code statically to ensure that the application is not vulnerable to issues like memory leaks, fulfilling the second requirement. Implementing both will integrate security testing into the SDLC, addressing the security concerns earlier in the development cycle, as recommended in CASP+.