I have a board with obviously some mistakes because its not properly running. Power control issues exists on board. About 12 Capacitors and Resistors need change or remove. 3 layer pcb, almost 7x5 cm. Freelancer must have experience in designing STM32 and sim900.
I can do PCB design in Altium Designer or in Cadence Orcad. I have great experience in circuit design and PCB design. The multilayer board including. I have worked with stm32 and sim900.