STM32 Real-Time Audio DSP & PCB

I’m building a self-contained DJ-style effects controller that lives entirely on an STM32 with its on-chip ADC/DAC. The unit must stream stereo audio, generate notes, and manipulate that signal on the fly... (Budget: $3000 - $5000 AUD, Jobs: Audio Engineering, Digital Signal Processing, Electrical Engineering, Electronics, Embedded Systems, Microcontroller, PCB Design and Layout, STM32)