Full Stack Developer – Custom Mobile & Web Applications (API Integration)

Job Description

Work Type: Freelance / Contract
Location: Remote
Industry: Automotive Services / Technology Integration

Project Overview

We are a multi-location car wash business operating with a centralized Point of Sale (POS) system. We are looking for an experienced Full Stack Developer to lead a custom integration project connecting our POS system with multiple digital platforms.

The goal is to build a secure, scalable API layer that powers internal tools, customer applications, and website functionality.

This role requires deep experience in API architecture, WordPress development, and system integrations, along with the ability to collaborate effectively with non-technical stakeholders.

What You’ll Be Building

The API integration will power several systems, including:

• Internal location management tools (mobile and web apps)
• Operations dashboards
• Membership enrollment systems
• Customer mobile application
• WordPress website integration with the POS platform

The project will be delivered in phases to validate integrations and reduce risk.

Key Responsibilities

• Design and implement custom API integrations with the POS system
• Build internal operations and membership management apps
• Develop and maintain custom WordPress plugins for integration
• Implement secure payment gateways and membership systems
• Support features such as:
  • User registration
  • Recurring memberships
  • Account management
• Provide technical guidance on architecture and best practices
• Document systems and integrations for long-term maintenance
• Collaborate with design and marketing teams during website redevelopment

Required Skills

• Strong full-stack development experience
• Expertise in:
  • REST APIs
  • JSON
  • PHP
  • Ruby
• Front-end development using React or Angular
• Experience with OAuth authentication systems
• Knowledge of secure payment handling and PCI compliance
• Understanding of modern web security practices
• Ability to explain technical concepts to non-technical teams
• Strong documentation skills

Preferred Experience

• Building custom WordPress plugins
• Integrating APIs with:
  • POS systems
  • CRM platforms
  • Payment gateways
• Developing enterprise-level mobile and web applications
• Understanding of UI/UX best practices
• Experience collaborating with product, design, and marketing teams

Engagement Details

• Remote freelance or contract role
• Work delivered in project phases
• Hourly or project-based compensation depending on experience
• Long-term collaboration potential

Ideal Candidate

• Experienced full-stack engineer with strong integration skills
• Comfortable leading architecture decisions
• Able to communicate clearly with business stakeholders
• Organized with strong documentation habits
• Interested in building scalable systems used across multiple platforms