KiCad PCB Review & Modification – USB-C PD Source + 24V Power Board

I’m looking for an experienced hardware engineer to review and refine an existing KiCad PCB design before prototype manufacturing. This is not a from-scratch design. The schematic and most of the layout already exist, but the design has recently been updated from a simpler I/O-expander board into a microcontroller-based vending machine control board. The goal is validation, issue finding, and practical corrections in KiCad. Project Overview: * 24V input power distribution/control board for a vending machine retrofit controller * Input protection: fuse, TVS, reverse polarity protection / PMOS ideal-diode style stage * 20V buck rail powering a USB-C Power Delivery source port for SBCs such as Radxa / Raspberry Pi-class boards * USB-C PD controller: TI TPS26750 with external EEPROM configuration and protected external VBUS path / eFuse * Separate 5V rail with USB-C 5V-only source output for touchscreen display/peripheral power * 3.3V logic rail * STM32G4 microcontroller replacing previous MCP23017 I/O expander architecture * USB-C USB 2.0 device/data port between SBC and STM32 * MDB cashless-payment interface for Nayax/MDB card reader support * 24V-to-34V boost converter section for MDB peripheral power using TI TPS43060 * MDB TX/RX physical interface between STM32 UART and MDB connector * 16 low-side MOSFET outputs for 24V vending motors/loads with flyback diodes * 4-layer PCB with internal ground and power planes Scope of Work: * Review schematic and PCB layout in KiCad * Validate STM32G4 support circuitry, USB data interface, SWD/debug, reset/boot, clocking, and pin assignments * Review MDB connector, 34V MDB boost supply, and MDB TX/RX physical interface * Validate USB-C PD source implementation, SPR up to 20V * Check TPS26750 PD controller implementation, EEPROM/config connections, and external protected VBUS path * Check TPS43060 boost converter design, external MOSFETs, current sensing, compensation, feedback, layout, and component ratings * Check power-path design, input protection, current handling, grounding, and rail sequencing * Review grounding, noise/EMI considerations, especially with switched 24V motor loads and switching converters * Check thermal considerations, trace widths, copper areas, and via usage * Verify footprints against datasheets * Identify reliability, manufacturability, and bring-up risks * Make corrections/modifications directly in KiCad where needed Requirements: * Proven PCB design experience, preferably in KiCad * Strong power electronics / DC-DC converter experience * Experience with USB-C Power Delivery source designs, not only sink designs * Experience with STM32 microcontroller hardware design * Experience with mixed power/control boards involving motors, inductive loads, and external harnesses * Familiarity with MDB vending-machine interfaces is highly preferred * Familiarity with TI TPS26750, TPS43060, or similar parts is a plus Deliverables: * Reviewed and corrected KiCad project files * Brief summary of key issues found and changes made * Notes on any remaining risks or recommended prototype bring-up checks Timeline: * Expected turnaround around 1 week, flexible but not intended as a long-term project Additional Notes: * This is a commercial project * The board is intended as a prototype for a vending machine retrofit controller * Potential for future work if the collaboration goes well When applying, please briefly describe your experience with: * USB-C PD source designs * DC-DC converter layout/review * STM32 hardware design * MDB/vending-machine interfaces, if applicable