J-JACK Mobile App & Embedded Systems Developer — iOS, Android, ESP32 & Hydraulics

J-JACK Mobile App & Embedded Systems Developer — iOS, Android, ESP32 & Hydraulics

Company: Jay Logistics & Trade LLC
Product: J-JACK Smart Bluetooth Hydraulic Jack
Location: Houston, Texas / Remote or Hybrid, depending on hardware testing requirements
Compensation: $3,000 per month after the agreed commercial launch milestone, plus eligibility for a management-approved sales participation agreement
Anticipated Start: Following the qualifying J-JACK preorder launch or commencement of final-product production, as established in a written agreement

About J-JACK

Jay Logistics & Trade LLC is developing J-JACK, a smart hydraulic jack that combines mechanical lifting technology, embedded electronics, and mobile connectivity.

We are seeking an experienced developer who can take responsibility for designing, coding, testing, and delivering the J-JACK mobile application and its integration with the product’s embedded control system.

This position requires hands-on development experience across iOS, Android, ESP32, and Arduino-based systems, along with a practical understanding of hydraulics. The ideal candidate understands how software commands translate into physical equipment behavior and can collaborate closely with mechanical, electrical, and manufacturing personnel.

This is a hands-on engineering position. Candidates must be able to personally develop and troubleshoot working software and firmware, demonstrate previous projects, and support development through production readiness.

Position Overview

The developer will help turn J-JACK’s product requirements into a complete application and connected-device experience. Responsibilities include application design, mobile development, Bluetooth communication, embedded integration, data handling, testing, documentation, and launch support.

The application and firmware must operate together reliably. Device behavior must account for interrupted connections, invalid commands, power changes, sensor faults, and other conditions that can occur when controlling physical equipment.

Final features and control permissions will be determined through engineering review, hardware capabilities, testing, and management approval.

Primary Responsibilities

Mobile Application Design and Development

• Design clear, intuitive application screens for iOS and Android.
• Develop wireframes, user flows, interactive prototypes, and production application interfaces.
• Build and maintain the application using an appropriate native or cross-platform technology stack.
• Recommend the development approach based on hardware compatibility, reliability, maintainability, and long-term support.
• Create device discovery, pairing, connection, reconnection, and connection-status experiences.
• Develop device setup, operating instructions, equipment status, alerts, and troubleshooting screens.
• Implement approved control functions with clear feedback, appropriate confirmations, and safeguards against accidental commands.
• Support different screen sizes, supported operating system versions, and accessibility requirements.
• Prepare application builds, release documentation, and submissions for the Apple App Store and Google Play.
• Troubleshoot crashes, performance issues, operating system changes, and customer-reported defects.

ESP32, Arduino, and Embedded Integration

• Develop, review, and troubleshoot ESP32 firmware using Arduino frameworks and/or ESP-IDF.
• Write maintainable embedded C/C++ code.
• Design and document communication between the mobile application and embedded controller.
• Implement Bluetooth Low Energy services, characteristics, command formats, acknowledgments, and status updates.
• Integrate applicable sensors, switches, motor controls, relays, and other approved electronic components.
• Work with electrical engineers to verify signal requirements, wiring assumptions, component interfaces, and power behavior.
• Implement command validation, timeouts, watchdog behavior, and fault reporting.
• Establish defined device behavior during connection loss, restart, low voltage, and interrupted operations.
• Support secure device provisioning and firmware updates where technically appropriate and approved.
• Maintain firmware versions and compatibility information across prototype and production hardware.

Hydraulics and Equipment Control

• Apply practical knowledge of hydraulic jacks, pumps, valves, actuators, pressure, loading, and controlled movement.
• Understand how …