Back End Developer

Company Description

Hamhey Corp is revolutionizing the relocation experience by building the world’s first fully AI-powered platform designed for international students and expats. Unlike traditional platforms, Hamhey manages the entire relocation process—from housing and paperwork to banking and legal assistance—all within a single, secure platform. By leveraging AI, the platform automates complex processes while providing personalized, hands-on support. The company's mission is to empower individuals to move abroad confidently by removing uncertainty, complexity, and risks from the relocation journey.

Technology Stack & RequirementsRequired Technical Skills

• 4+ years backend development
• Strong Next.js (App Router) and Node.js
• TypeScript
• PostgreSQL design and optimization
• Prisma ORM
• RESTful API design
• Authentication and authorization (NextAuth.js, JWT, OAuth)
• Payment integration (Stripe)
• AWS (S3, presigned URLs)
• Real-time systems (WebSocket, Socket.io)
• Webhooks and event handling
• API security best practices

Preferred Skills

• Database optimization and query tuning
• Background job processing (queues, workers)
• Email service integration (Resend, SendGrid, etc.)
• PDF generation
• Multi-currency handling
• GDPR compliance
• CI/CD (GitHub Actions, Vercel)
• Error monitoring (Sentry, etc.)
• API documentation (OpenAPI/Swagger)
• GraphQL (optional)

Core Responsibilities1. API Development & Architecture

• Design, develop, and maintain RESTful APIs using Next.js API Routes
• Build scalable, maintainable endpoints (50+)
• Implement consistent request/response patterns
• Design API architecture for performance and scalability
• Version APIs and maintain backward compatibility
• Write API documentation

2. Database Design & Management

• Design and optimize PostgreSQL schemas using Prisma
• Create and manage migrations
• Optimize queries and indexes
• Handle complex relationships and data integrity
• Implement proper indexing strategies
• Database performance monitoring and tuning
• Backup and recovery procedures

3. Authentication & Authorization

• Implement multi-provider authentication (NextAuth.js)
• OAuth integration (Google)
• Role-based access control (CUSTOMER, PARTNER, ADMIN)
• Session management and token handling
• Secure API endpoints
• Mobile authentication endpoints (/api/mobile/auth/*)
• Password management and security

4. Payment Processing Integration

• Stripe integration (payments, subscriptions, Connect)
• Webhook handling for payment events
• Recurring subscriptions for tenant rent
• Multi-currency support
• Payment method management
• Invoice and receipt generation
• Failed payment handling and retry logic
• Prorating and installment calculations

5. Complex Business Logic Implementation

Customer Onboarding:

• 9-step onboarding with state management
• GDPR consent tracking
• Multi-step form validation
• Profile completion workflows

Tenant Onboarding:

• Existing tenant digitization
• Invitation token system
• Stripe subscription setup
• Payment history import

Booking System:

• Booking creation and management
• Status transitions
• Automated confirmations
• Deposit installment logic

Property Management:

• Property CRUD operations
• Photo and media handling
• Search and filtering
• Status management

B2B/B2C Leads:

• Lead management system
• CRM functionality
• Assignment workflows
• Audit logging

6. Third-Party Integrations

• AWS S3 for file storage (presigned URLs)
• Email services (transactional emails, templates)
• SMS (optional)
• Maps/Geocoding (Google Maps API)
• PDF generation and templates
• QR code generation
• WebSocket for real-time features
• Browser automation (Stagehand integration)

7. File Management & Storage

• AWS S3 integration with presigned URLs
• File upload handling
• Document processing
• Image optimization
• Secure file access control
• File metadata management

8. Real-Time Features

• WebSocket implementation with Socket.io
• Real-time notifications
• Live updates (bookings, appointments, payments)
• Event-driven architecture
• Push notification infrastructure

9. Background Processing

• Queue system for async jobs
• Background job processing
• Email queue management
• Payment retry logic
• Scheduled tasks
• Batch operations

10. Security & Compliance

• API security (rate limiting, CORS)
• Input validation and sanitization (Zod)
• SQL injection prevention
• XSS protection
• GDPR compliance
• Data encryption
• Audit logging
• Security best practices

11. Testing & Quality Assurance

• Unit tests for business logic
• Integration tests for API endpoints
• Test Stripe webhooks
• Database transaction testing
• Error handling tests
• Performance testing
• Security testing

12. Performance Optimization

• Database query optimization
• API response caching
• Connection pooling
• Indexing strategies
• API rate limiting
• Load balancing considerations
• Performance monitoring

Current Backend ArchitectureFramework & Language

• Next.js 15 with App Router
• TypeScript 5.0+
• Node.js 18+
• Next.js API Routes (file-based routing)

Database & ORM

• PostgreSQL 15+
• Prisma 6.0+
• Complex schema with 30+ models
• Migrations and schema management

Key API Endpoints (50+)

• Authentication: /api/auth/* (NextAuth, OAuth, role management)
• User Management: /api/user/*, /api/admin/users/*
• Properties: /api/properties/*, /api/partner/properties/*
• Bookings: /api/bookings/*, /api/partner/bookings/*
• Payments: /api/payment/*, /api/stripe/*
• Tenant Management: /api/tenant/*, /api/admin/tenants/*
• Documents: /api/documents/*
• Notifications: /api/notifications/*
• Mobile APIs: /api/mobile/auth/*
• Admin APIs: /api/admin/* (B2B leads, analytics, stats)
• Webhooks: /api/webhooks/stripe/*, /api/webhooks/signwell/*

Integrations

• Stripe (payments, subscriptions, Connect, webhooks)
• AWS S3 (file storage, presigned URLs)
• Email services (Resend/Nodemailer for transactional emails)
• NextAuth.js (authentication, OAuth providers)
• Socket.io (real-time notifications)
• Browser automation (Stagehand for web scraping)

Technical RequirementsDatabase Schema Complexity

• 30+ models with complex relationships
• User management with roles and profiles
• Property management with metadata
• Booking system with payment tracking
• Document management
• B2B/B2C lead management
• Appointment scheduling
• Notification system
• Audit logging

API Design Patterns

• RESTful principles
• Consistent error handling
• Request/response validation with Zod
• Role-based access control
• Pagination and filtering
• Search functionality
• Batch operations support

Security Requirements

• Session-based authentication
• JWT token handling
• OAuth 2.0 implementation
• Role-based authorization
• Rate limiting
• Input sanitization
• SQL injection prevention
• XSS protection
• GDPR compliance

Specific Technical Challenges1. Payment Processing

• Stripe subscription management
• Webhook reliability and idempotency
• Failed payment retry logic
• Multi-currency conversion
• Prorating calculations
• Installment handling

2. Tenant Onboarding Flow

• Invitation token system with expiry
• Payment method setup integration
• Subscription activation
• Offline payment history import
• Complex state management

3. Real-Time Features

• WebSocket connection management
• Notification delivery
• Event broadcasting
• Connection scaling

4. File Management

• Presigned URL generation
• Large file uploads
• Image processing
• Secure access control
• Storage optimization

5. Background Processing

• Queue management
• Job retry logic
• Email delivery tracking
• Payment reconciliation
• Scheduled tasks

Development ResponsibilitiesCode Quality

• Write clean, maintainable TypeScript
• Follow best practices and patterns
• Code reviews
• Refactor legacy code when needed
• Document complex logic

Collaboration

• Work with frontend developers
• Coordinate with mobile developers
• Collaborate with product team
• Participate in architecture decisions
• Mentor junior developers (if applicable)

Deployment & DevOps

• Deploy to production (Vercel)
• Database migration management
• Environment configuration
• Monitoring and logging
• Error tracking and alerting

Performance & ScalabilityCurrent System Scale

• 50+ API endpoints
• Complex database schema
• Multiple user roles
• Real-time features
• Payment processing
• File storage integration

Optimization Areas

• Database query optimization
• API response times
• Caching strategies
• Background job processing
• Connection pooling
• Index optimization

Project Timeline & DeliverablesOngoing Responsibilities

• Maintain existing backend infrastructure
• Implement new features and endpoints
• Optimize performance
• Fix bugs and security issues
• Update dependencies
• Improve code quality

Upcoming Features

• Enhanced mobile API endpoints
• New payment features
• Advanced analytics
• Improved tenant management
• Additional integrations
• Performance optimizations

What We Offer

• Competitive salary
• Flexible work arrangements (remote/hybrid)
• Opportunity to work on complex technical challenges
• Collaborative team environment
• Professional growth opportunities
• Modern tech stack
• Exposure to full-stack architecture

Application Requirements

Please provide:

• GitHub/GitLab profile
• Examples of backend projects (APIs, databases, integrations)
• Experience with similar tech stack
• Resume/CV
• Availability and preferred work arrangement
• Any relevant certifications or coursework