مطوّر Backend محترف (Node.js/PostgreSQL) لمنصة تخص الكافيهات

## Overview

We are building a next-generation platform for coworking spaces from the ground up. Think of it as a "hybrid" system that serves two critical functions:

The Utility Side (Phase 1):

- Members can browse and book meeting rooms by the hour

- Manage their membership subscriptions and billing

- Order food/drinks from the on-site café

- View upcoming events and space availability

The Community Side (Phase 2):

- Member directory with professional profiles (opt-in)

- Skill-share board for collaboration opportunities

- Real-time chat rooms for different interest groups

- Activity feed and notifications

This is not a simple CRUD app. We need a senior backend developer who can architect a secure, scalable, and high-performance foundation for a platform that will run both a physical business and a digital community simultaneously.

Our team: You'll be working closely with an experienced product designer who will handle all UI/UX work. We value collaboration and clear communication between design and development.

We are not looking for a quick, cheap gig. We are building a long-term technical partnership with our go-to backend developer for this and future projects.

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## Core Responsibilities

- Architect and build a scalable, secure, and maintainable REST API from scratch using Node.js

- Design a complex relational database (PostgreSQL) to manage users, multi-tiered memberships, recurring subscriptions, and real-time meeting room reservations (handling concurrency and preventing double-bookings)

- Integrate the Stripe API to handle complex payment flows, including subscriptions, one-off invoices, and metered billing for resources

- Develop the backend infrastructure for a real-time community platform, including member profiles, skill-share boards, and multi-user chat rooms

- Collaborate with our product designer to define API contracts, data structures, and technical feasibility of features

- Ensure the entire system is high-performance and secure, implementing best practices for authentication, authorization, and data protection

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## Must-Have Technical Requirements

- Expert-level mastery of Node.js (preferably with Nest.js or Express frameworks)

- Deep, demonstrable experience in designing complex relational databases (PostgreSQL required). You must be able to think beyond simple tables and design for complex relationships, constraints, and data integrity

- Proven, production-level experience with Stripe payment gateway integration (specifically Subscriptions and payment processing)

- Experience building secure authentication/authorization systems (JWT, OAuth, role-based access control)

- Understanding of API security best practices (rate limiting, input validation, SQL injection prevention, CORS)

- Experience with real-time features (WebSockets, Server-Sent Events, or similar technologies)

- Full-stack experience and understanding of frontend frameworks like React is a major plus, but your core expertise must be in backend architecture

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## Technical Architecture Requirements

The platform must handle several complex, concurrent operations:

1. Meeting Room Reservations: Users can book rooms by the hour. The system must prevent double-bookings and handle timezone conversions properly.

2. Payment Processing: Integration with Stripe for membership subscriptions, one-time bookings, and café orders.

3. Real-Time Community Features: Live chat rooms, instant notifications, and activity feeds.

4. Data Consistency: To ensure absolute data integrity and simplify the architecture, all user sessions must be stored in the PostgreSQL database with a 30-day expiration policy. Each API request should validate the session by querying the sessions table before processing. This ensures we have a complete audit trail and can easily revoke access if needed.

5. Notification System: Users should receive instant notifications for booking confirmations, payment receipts, new messages, and community activity.

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## How to Apply: Your Proposal

To be considered, your proposal must include the following. Proposals that ignore these will be immediately archived.

1. Start by telling me which specific version of Node.js you would recommend for this project and why.

2. Answer this question (3-4 paragraphs):

- Describe your proposed high-level technical architecture for this platform

- Specifically address how you would handle the session management and authentication system described above

- Explain your approach to ensuring the real-time chat and booking system can scale as the user base grows

- Discuss any technical concerns or alternative approaches you would recommend

3. Portfolio evidence: mention one project in your portfolio that is most relevant to this job and explain why in 2-3 sentences.

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## What We Value

- Problem-solvers over order-takers: We want someone who will challenge requirements if they spot potential issues

- Clear communicators: You'll be working with a designer and potentially other developers. We need someone who can explain technical concepts clearly

- Long-term thinking: We're building for scale and maintainability, not just "make it work"

- Team players: You should be comfortable collaborating, giving and receiving feedback, and contributing to technical decisions

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## Next Steps

We will review all proposals and conduct video interviews with the top 3-5 candidates. During the interview, we'll discuss the technical architecture in depth and may ask you to walk through how you've solved similar challenges in past projects.

We're excited to find the right technical partner for this project. If you're an A-player who loves solving complex problems, we want to hear from you.