Industrial Sensor Datalogger PCB Design

We are Safe Instrumentación (Bogotá, Colombia). We design a modular data-acquisition system for geotechnical and industrial instrumentation, with four boards: a main "Brain" (STM32G0B1RE, FRAM, LoRa, LTE modem, RS-485, native USB) and three accessory nodes (vibrating-wire VM501C, inclination SCL3400, and a DS18B20 temperature chain of up to 200 sensors).

We already have a working prototype. We do NOT need firmware — we develop it ourselves. We need a senior engineer (or firm) to take the hardware to production:

Review and optimize the existing schematics
Verify and strengthen protections (ESD, surge, EFT; galvanic isolation on RS-485; reverse-polarity/overcurrent)
Optimize power management and consumption (seamless mains/battery switching, low-power modes, load-switching of peripherals, power budget per mode)
Design the multilayer PCBs (Altium or KiCad)
Prepare the boards for CE and FCC certification (using pre-certified RF modules)
Deliver full manufacturing files (Gerbers, NC Drill, Pick-and-Place, production BOM with MPNs)
Specify industrial terminal blocks, labeled test points, and full silkscreen

Full scope in the attached document (English/Spanish).

Required from candidates:

Proven experience taking designs through CE / FCC labs — please share an FCC ID of a product you designed and/or a CE technical file you prepared, for verification
Contactable client references
Portfolio of similar industrial/instrumentation work
Signature of an NDA before receiving our schematics

Please send a fixed-price proposal with milestones.