Gradhire - Student Internship Platform

Executive Summary

Context: university internship/apprenticeship marketplace and workflow (offers → applications → approvals → tracking).
My scope: authentication/authorization, database design, and core workflow modules in a 4-person team.
Engineering focus: LDAP + external accounts, RBAC boundaries, PostgreSQL modeling for both workflows and dashboards.
Stack: PHP, PostgreSQL, LDAP, Tailwind CSS, Docker.

Introduction

Gradhire is a web platform I helped develop as part of a four-person academic team at IUT Montpellier-Sète. The platform serves as a critical bridge between computer science students and potential employers, streamlining the internship and apprenticeship search process. My role in this project involved designing and implementing key components of the application architecture, focusing particularly on the authentication system, database design, and several core functional modules.

The platform addresses a critical pain point in the academic-professional transition: connecting students with relevant local opportunities matched to their skills while providing companies with a streamlined system to find qualified candidates. Gradhire emerged as a solution to centralize and simplify this process, replacing fragmented systems with a unified platform serving the needs of students, academic staff, and businesses in the Montpellier region.

Project Scope and Initial Challenges

Project Scope: The Gradhire project had several well-defined requirements:

Create a secure platform with role-based access control for students, staff, and businesses
Implement a user-friendly internship/apprenticeship posting and application system
Develop an LDAP-based authentication system for academic users
Design a comprehensive database to track all aspects of the internship process
Build a visually appealing, responsive user interface
Complete the project within a strict academic timeframe

Initial Challenges: Several technical challenges had to be addressed early in the development process:

Authentication Complexity: The platform needed to support both LDAP authentication for university members and traditional authentication for businesses, requiring a dual-approach system.
Database Design: The complexity of tracking internship offers, applications, assignments, evaluations, and user roles demanded sophisticated database architecture.
Academic Integration: The system needed to seamlessly integrate with existing university processes, including internship validation, professor assignments, and evaluation systems.
Security Concerns: Given the platform would store personal student data and company information, robust security measures were essential.
User Experience: Creating an intuitive interface that would work for multiple stakeholders with different needs and technical abilities.

Technology Stack and Architectural Decisions

To address these challenges, we carefully selected a technology stack optimized for both robust backend functionality and a responsive frontend experience:

Backend Architecture:

PHP: Chosen as the primary server-side language for its wide support, mature ecosystem, and compatibility with university infrastructure
PostgreSQL: Selected over MySQL for its advanced data integrity features, better type handling, extended functionality with triggers, and superior performance characteristics
LDAP Integration: Implemented for seamless authentication with existing university credentials

Frontend Technologies:

JavaScript: Used for client-side interactivity, form validation, and dynamic content updates
Tailwind CSS: Adopted for consistent styling and responsive design
SVG: Implemented for dynamic statistical representations in the dashboard

Additional Tools and Libraries:

OpenAI API: Integrated for intelligent matching of student profiles with job opportunities
FPDF: Utilized for generating PDF documents for internship contracts and simulations
Custom Form Builder: Developed an internal form creation system for consistent validation and user experience

The system followed a rigorous Model-View-Controller (MVC) architecture to maintain separation of concerns, improve code maintainability, and streamline the development process. This approach allowed team members to work on different components simultaneously without conflicts.

Core System Components

Authentication System

I developed a dual-authentication system to accommodate both university members and business users:

LDAP Authentication: For university members (students and staff), the platform integrates with the institution's LDAP server, allowing users to log in with their existing university credentials. This approach eliminated the need for students to create and remember additional accounts.

Business Accounts: For companies and external tutors, I implemented a traditional email-based registration system with secure password handling using salting and peppering techniques with SHA-256 hashing. The system includes email verification and password recovery functionalities.

Role-Based Access Control: Once authenticated, users gain access to different sections of the platform based on their roles:

Students can browse offers, submit applications, and track their internship process
Academic staff can validate internships, assign tutors, and evaluate student performance
Department heads can modify user roles and access administrative functions
Companies can post offers, review applications, and manage their tutors

Database Architecture

The PostgreSQL database design was one of the most critical components of the system, with 29 tables structured to track all aspects of the internship process. Key architectural decisions included:

Table Inheritance: I leveraged PostgreSQL's inheritance capabilities to create specialized offer types (internships and apprenticeships) while maintaining a unified base structure, simplifying queries and ensuring data integrity.

Materialized Views: To optimize dashboard performance, I implemented seven materialized views that pre-compute statistics and are automatically refreshed through triggers when relevant data changes.

Functions and Procedures: The database includes 23 custom functions and 18 stored procedures that encapsulate complex operations, such as user creation, role retrieval, and parameter management, reducing application code complexity.

Triggers: Nine database triggers maintain data integrity and automate processes, including:

Seven triggers for refreshing materialized views
A trigger to ensure tutors don't exceed their student assignment limits
Data validation triggers to enforce business rules

Custom Types: PostgreSQL's type system was utilized to create enumeration types for roles and other categorized data, ensuring only valid values can be inserted.

Offer Management System

The offer management system forms the core of the platform, allowing companies to post internship and apprenticeship opportunities while students can browse and apply for positions matching their skills:

Offer Creation:

Companies can create draft offers and submit them for administrative approval
Administrators can create offers on behalf of companies
Offer information includes type (internship/apprenticeship), subject, thematic area, schedule details, compensation, and location

Validation Workflow: To maintain quality standards, all company-submitted offers go through an approval process by administrative staff before being published. This ensures only legitimate, well-structured offers reach students.

Search and Filtering: Students can browse offers using an advanced filtering system that narrows results by:

Type (internship/apprenticeship)
Thematic area
Duration
Location
Compensation

Newsletter Integration: Students can subscribe to themed newsletters, automatically receiving email notifications when new offers matching their selected categories are published.

Application Tracking System

The application process was designed to be transparent and efficient:

Application Workflow:

Students submit applications with their CV and cover letter
Companies receive notifications and review applications
Companies accept or reject applications
Students confirm acceptance of offers
Academic tutors are assigned to accepted students
Company tutors are designated to supervise students

Document Management: The system handles the secure storage and retrieval of application documents, including CVs, cover letters, and eventual internship reports.

Status Tracking: All participants can track the current status of applications through a unified interface, with different views optimized for students, companies, and staff.

Advanced Features

Dashboard and Analytics

For administrators and businesses, I designed a statistical dashboard using SVG-based visualizations that provides insights into platform activity:

Key Metrics:

Percentage of students with active internships/apprenticeships by year
Most popular thematic areas
Number of internships vs. apprenticeships
Average applications per offer by domain
Distribution of offers by thematic area
Recent offer listings

Performance Optimization: To ensure fast loading times despite complex calculations, the dashboard uses materialized views that are automatically refreshed when relevant data changes, providing near real-time statistics without query performance penalties.

Custom Router and Form System

To improve development efficiency and create a consistent user experience, I developed two core internal frameworks:

Custom Router:

Inspired by Express.js and Laravel, our router handles HTTP verb mapping, parameter extraction, and controller routing
Supports dynamic route parameters like /gererNote/modifier/{id}
Includes request objects that encapsulate HTTP method, body data, and cookies

Form Builder System:

Streamlines form creation with consistent validation and styling
Supports 13 input types with dynamic validation rules
Handles client-side validation, server-side validation, and error reporting
Drastically reduces HTML complexity and improves code maintainability

Internship Convention Management

The platform includes a comprehensive system for managing the administrative aspects of internships:

Convention Generation:

PStage simulation feature allows students to generate internship convention documents
Administrative approval workflow for convention validation
PDF generation for official documentation

Visitation Scheduling:

Calendar interface for planning and viewing academic tutor visits to companies
Email notifications for all participants
Visit report submission and tracking

Evaluation System:

Student performance assessment by both academic and company tutors
Public and private feedback mechanisms
Numerical grading with detailed rubrics

Security Measures

Security was a primary concern throughout development. Key security implementations included:

SQL Injection Prevention: All database queries use prepared statements that separate SQL commands from user data, preventing injection attacks.

XSS Protection: User-submitted content is filtered and encoded before display, preventing cross-site scripting vulnerabilities.

Password Security: Business user passwords are secured using:

Unique salts for each user
Additional pepper values stored separately from the database
SHA-256 hashing algorithm

Role-Based Access Controls: Fine-grained permission system ensures users can only access appropriate features and data.

Data Archiving: Instead of permanent deletion, user accounts and offers are archived, maintaining data integrity while complying with user privacy requests.

Deployment Strategy

For deployment, we utilized a containerized approach:

Docker Implementation:

Separate containers for the web application and chatbot
Consistent environment across development and production
Simplified deployment process

AWS EC2 Hosting:

Reliable and cost-effective server infrastructure
Configured for optimal performance and security

Project Management and Workflow

The project followed an Agile Kanban methodology using the Github organisation :

Continuous Delivery Approach: Rather than fixed sprints, features were delivered as soon as they were completed, allowing for rapid iteration and feedback incorporation.

Asynchronous Coordination: While we held regular stand-up meetings three times weekly, most coordination happened asynchronously through GitHub, maximizing productive coding time.

Version Control: All code was managed through GitHub with proper branching strategies, code reviews, and issue tracking.

Outcomes and Impact

Gradhire successfully fulfilled its academic project objectives and delivered tangible benefits:

Technical Achievements:

Developed a fully functional, secure platform with role-based access
Implemented complex business logic matching university internship processes
Created a responsive user interface that works across devices
Built a system capable of handling thousands of users and offers

User Benefits:

Students gained a centralized platform for discovering and applying to opportunities
Companies received a streamlined system for recruiting qualified interns
Academic staff obtained tools for monitoring and managing the internship process
All stakeholders benefited from improved communication and transparency

Learning Outcomes:

Applied theoretical knowledge to a practical, real-world problem
Gained experience with full-stack development, database architecture, and security implementation
Developed collaborative skills through team-based development
Created a portfolio piece demonstrating technical abilities

Conclusion

The Gradhire project exemplifies how academic learning can be applied to create practical solutions for real-world challenges. By developing this comprehensive internship platform, our team not only fulfilled course requirements but also created a valuable tool for the university community.

From a technical perspective, the project demonstrated the effectiveness of MVC architecture, the power of PostgreSQL's advanced features, and the efficiency gains possible through custom frameworks like our router and form system. The security implementations show a mature understanding of web application vulnerabilities and appropriate mitigation strategies.

The most significant takeaways from this project include:

Architecture Matters: The early investment in solid architecture paid dividends throughout development, making feature additions and modifications straightforward.
Database Design is Critical: The sophisticated PostgreSQL implementation with inheritance, materialized views, and triggers provided both performance and data integrity benefits.
Custom Frameworks Improve Efficiency: Building internal tools like the router and form system dramatically reduced code complexity and improved consistency.
Security Cannot Be an Afterthought: By implementing security measures from the beginning, we avoided the common pitfall of retrofitting security onto an insecure foundation.
User Experience Drives Adoption: Focusing on intuitive interfaces and clear workflows ensured the platform would be useful to all stakeholders, regardless of technical proficiency.

As the codebase is available on GitHub, future student cohorts can continue to enhance and expand the platform, building on our foundation to create an even more powerful tool for connecting students with valuable professional experiences.

Technologies Used

PHP
JavaScript
PostgreSQL
OpenAI API
LDAP
Docker
Tailwind CSS
FPDF
SHA-256 Encryption
SVG
Agile Kanban
GitHub
AWS EC2