Hardware Engineer Needed: Custom ESP32 + Dynamic NFC PCB & 3D Enclosure Design (USB-Serial)

Job Description: I am looking for an experienced Embedded Systems Hardware & PCB Design Engineer to create a prototype for a smart, countertop retail device. The purpose of this device is to replace paper receipts. When a sale finishes on a point-of-sale (POS) computer, the register will send a unique digital receipt URL to this device over a wired USB-C Serial connection. The device will write that URL to an NFC chip so a customer can tap their phone and open their digital receipt instantly. We have already mapped out the core hardware components and logic. Now, we need a professional to turn this into production-ready blueprints and a matching 3D enclosure. Scope of Work: Schematic & PCB Design: Create a clean, compact circuit board layout that integrates: Microcontroller: ESP32 module (e.g., ESP32-WROOM or ESP32-S3) powered and programmed via a USB-C port. NFC Chip: ST25DV64KC dynamic NFC chip (communicating with the ESP32 via I2C). Indicators: Circuitry/GPIO mapping to drive two 5V industrial metal panel-mount LEDs (Red and Green) for user feedback. Power/Data: Power must be drawn directly from the host computer's USB-C port (no external batteries or wall bricks). Design for Manufacturing (DFM): The board must be optimized so it can be manufactured seamlessly by turnkey factories like PCBWay or JLCPCB. 3D Enclosure Design (CAD): Design a sleek, professional, 3D-printable plastic countertop case that perfectly houses the custom PCB. The case needs clean cutouts for the USB-C port, the two top-facing LEDs, and a clearly indicated "Tap Here" zone over the NFC antenna. Required Deliverables: Complete Gerber files (including drill files, pick-and-place, and solder mask). An optimized Bill of Materials (BOM) with verified manufacturing part numbers (DigiKey/Mouser friendly). CPL/Centroid file for automated component placement. Complete 3D CAD files (.STEP and .STL) for the enclosure. Clear wiring/schematic documentation. Freelancer Requirements: Proven experience with ESP32 hardware implementation and multi-layer PCB design. Experience working with I2C protocols and RFID/NFC chips (specifically ST25 or NTAG families is a huge plus). Proficiency in Altium Designer, KiCad, or Autodesk Eagle. Ability to design both the PCB and the 3D enclosure is highly preferred to ensure a flawless physical fit. Screening Questions (Add these to the Upwork posting): Have you designed custom hardware around the ESP32 chip before? Please briefly describe or link a picture of a past project. Do you have experience designing the 3D plastic enclosure to fit your custom PCBs, or do you only focus on the electronics side? Which PCB design software (KiCad, Altium, Eagle) do you plan to use for this project?