Survision

Overview

Built and scaled an end-to-end data collection platform supporting 1,000+ monthly active users and processing 50,000+ responses/month using NestJS, TypeORM, PostgreSQL, Redis, and TypeScript. Developed the mobile application with React Native (Expo), integrating secure APIs and real-time features. Optimized platform performance by 35% and lowered operational costs by replacing Google Maps APIs with a self-hosted Nominatim service and developing a cached geolocation module. Increased system reliability and processing speed by 42% by designing scalable background job systems for notifications, emails, referrals, and survey workflows using Redis and BullMQ. Designed and operated production infrastructure on private VPS using Docker, Coolify, Nginx, and Traefik, implementing CI/CD pipelines, Linux hardening, and a self-hosted S3-compatible object storage (MinioS3). Maintained 99.5%+ system uptime and reduced incident resolution time by implementing centralized logging, real-time monitoring, and automated alerting using a self-hosted Grafana stack, Loki, Promtail, and Uptime Kuma.

Key Features

• Survey Creation and Management: Allows admins to create, update, and manage surveys, including setting titles, descriptions, target audiences, and pricing.
• Region-Based Targeting: Enables surveys to be targeted to specific geographic regions (Wilayas) within Algeria.
• Collector Management: Provides tools for managing collectors, including status verification and profile updates.
• Real-time Location Tracking: Uses collector location data to assign relevant surveys based on proximity.
• Create a nominatim library to manage location searching and reverse geocoding.
• Diffrent qusetion types: Supports multiple question types, including multiple-choice with others , free , radio ,etc...
• Survey Assignment and Filtering: Implements logic to assign surveys to collectors based on their location and survey status (active, paused, completed).
• Role-Based Access Control: Implements different roles (admin, collector, company) with associated permissions.
• Data Analytics and Reporting: Includes features for counting surveys, tracking survey status, and calculating response rates.
• Payment and Transaction Management: Supports payment processing and transaction tracking for collectors.
• Reports : Allow user to send reports and manage them.
• Fraud Detection: Implements mechanisms to detect and prevent fraudulent activities and submissions by collectors.
• Authentication and Authorization: Implements secure login and registration processes for different user roles.
• Detailed Statistics: Provides in-depth statistics on surveys, collectors, and responses for better decision-making.
• Email Notifications: Sends email notifications for various events, such as account verification and demo requests.
• Collector Referral System: Implements a referral system for collectors to invite others and earn rewards.
• Company Referral System: Enables companies to refer their collectors to Survision.
• Company Profile Management: Allows companies to manage their profiles, including company size, contact information, and website details.
• API Documentation with Swagger: Uses Swagger to document and expose the API endpoints.

Technical Challenges

• Ensuring accurate location data and survey assignment.
• Maintaining data privacy and security, especially regarding user location and personal information.
• Scaling the platform to handle a large number of surveys, collectors, and responses.
• Optimizing database queries for performance, especially when filtering surveys by Wilaya and status.
• Handling potential conflicts when adding Wilayas to surveys.
• Implementing robust error handling and logging.
• Managing collector verification and status updates.
• Integrating with external services for location data and payment processing.
• Creating a user-friendly interface for survey creation and management.
• Keeping the application up-to-date with the latest security patches and best practices.