Mixed-Signal PCB & Prototype Build

I have an optical‐sensing board that is already architected at block level and now needs to move fast into hardware. The immediate work spans three linked stages—schematic finalization, PCB layout, and hands-on prototype assembly—so I’m looking for someone comfortable seeing a mixed-signal design all the way from Altium (or KiCad) files to a powered-up bench unit.

Key technical themes you will tackle include low-noise op-amp signal conditioning, LED driver sequencing, high-impedance multiplexer routing, and an STM32-class MCU front-end for ADC capture. Because the board is ultimately destined for a medical-device environment, meeting typical EMC/EMI compliance practices is a must; please factor this into component placement, ground strategy, stack-up, and filtering choices.

Turnaround is ASAP. To keep things focused, here is how I plan to accept the work:

• Schematic: cleaned, fully annotated, with DRC cleared and reference designators locked.
• Layout: production-ready Gerbers, drill files, stack-up drawing, and a 3D model that aligns with our mechanical envelope.
• BOM: costed, with second-source options for any parts >12-week lead time.
• Assembly package: pick-and-place, stencil data, and a short reflow profile guide.
• Bring-up support: remote help during first power-on, including tweaks to pass basic noise-floor and LED current tests.