ESP32 Firmware for Multi-Tap Water Dispenser

I have an MQTT backend and basic ESP32 firmware stub and need an experienced developer to complete/rewrite it into a production-ready solution.

Hardware: ESP32 Dev Module, 6× 12V solenoids, 6× YF-S201 flow sensors, MFRC522, MIFARE 1K cards.

Requirements
Accurately dispense user-defined volumes, especially 20L per tap, based on actual flow measurement.
Support all 6 taps simultaneously with non-blocking/real-time firmware.
RFID card authentication and balance deduction.
MQTT price lookup, transaction publishing and balance reconciliation.
Automatic offline mode with encrypted local card balances and pending transactions.
Automatically sync transactions when connectivity returns.
Reliable handling of reboot, Wi-Fi/MQTT disconnection and power interruption.
Configurable tap calibration, pricing, GPIOs, MQTT credentials, etc.
Deliverables
Complete buildable ESP-IDF or Arduino-ESP32 source code
Wiring diagram for flow sensors, solenoids/drivers and MFRC522
Short README for flashing, configuration, calibration and testing
Working demonstration on my current ESP32 development board.

I will provide the existing MQTT topic/payload structure.

Looking for someone experienced with ESP32, MQTT, RFID, flow sensors and concurrent/non-blocking firmware.