Project Overview

1.1 Purpose & Vision

"Last Checked In" is a Personal Relationship Manager (PRM). Its core purpose is to be a private, intentional tool that empowers users to be more consistent and thoughtful in nurturing their personal and professional relationships. It provides each user with a secure, private account to manage their connections, combating the passive nature of social media by providing an active tool for connection.

1.2 Core Problem Solved

In a busy world, it's easy to lose touch with people we care about. This application solves that problem by providing a centralized, private dashboard for each user to:

• Track the last time they connected with a specific person.
• Set custom, flexible reminders for when to check in next.
• Keep private, timestamped, and editable notes on conversations to remember important details.
• Organize contacts with detailed information and a flexible tagging system.
• Receive proactive push notifications for their own overdue check-ins.

1.3 Target User & Philosophy

The app is designed for individuals seeking a private tool to manage their social and professional connections. It operates on a philosophy of intentionality over passive engagement.

• It is not a social network. All user data is sandboxed and for their eyes only.
• It is proactive, not reactive. The app prompts the user to reach out.
• It values quality over quantity, focusing on deepening existing relationships.

Feature Breakdown

2.1 User Accounts & Authentication

The application has been fundamentally re-architected into a full-featured, multi-user platform with a robust and secure account system.

• Signup: Users can create a new, private account using an email and password. Passwords are salted and hashed using bcrypt.
• Login: Registered users can log in to access their sandboxed data.
• Session Management: The system uses JSON Web Tokens (JWTs) stored in the browser's localStorage to maintain user sessions.
• Data Sandboxing: A user can only see and interact with the data they have created.
• Logout: A logout button in the header allows users to securely terminate their session.

2.2 Core & Advanced Features (User-Specific)

• Contact Management: Add, edit, and view contacts with their name and a custom check-in frequency.
• Check-in System: Manually log a "check-in" to reset the reminder timer. Overdue contacts are visually highlighted.
• Notes System: Add, edit, and view multiple, timestamped notes for each contact.
• Expanded Contact Details: Store 'How We Met,' 'Key Facts,' and 'Birthday'.
• Tagging System: A flexible, many-to-many tagging system.
• Global Search: A search bar that filters contacts by name or note content.
• Archive/Restore System: Archive contacts instead of permanently deleting them.
• Multi-User Push Notifications: A daily scheduled backend job sends a single, dynamic summary push notification for each user's overdue contacts.
• Agenda View with Recurring Events: A forward-looking summary of all upcoming check-ins for the next 30 days.
• Granular & Intelligent Snooze: Granular options ("Tomorrow Morning", "3 Days", "1 Week") handled authoritatively on the backend.
• First-Time User Onboarding: A one-time, two-page welcome modal introduces the app's core concepts and powerful organizational features.

Technical Architecture

3.1 Technology Stack

• Frontend: React (Vite), React Router, JavaScript (ES6+), Axios, date-fns, Firebase SDK, react-hot-toast, vite-plugin-pwa, CSS Modules.
• Backend: Node.js, Express.js, PostgreSQL, bcrypt, jsonwebtoken, node-mailjet, node-cron, Firebase Admin SDK, dotenv, express-rate-limit, zod.
• Deployment:
  • Frontend: Vercel (as a Progressive Web App)
  • Backend: Render (Web Service)
  • Database: Render (PostgreSQL)
• Development & Tooling:
  • IDE: Visual Studio Code with Prettier
  • Version Control: Git / GitHub
  • Database Management: DBeaver