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Technology Stack

2KRIKA is built with modern, production-ready technologies chosen for reliability, performance, and developer experience.

Core Technologies

Runtime & Language

Technology Version Purpose
Node.js v22 JavaScript runtime
TypeScript ^5.8.3 Type-safe JavaScript
pnpm 10.7.1 Fast, efficient package manager

Why TypeScript? - Type safety catches bugs at compile time - Better IDE support and autocomplete - Self-documenting code - Easier refactoring

Framework

Technology Version Purpose
NestJS ^11.0.20 Progressive Node.js framework
Express (via NestJS) HTTP server

Why NestJS? - Built-in dependency injection - Modular architecture - TypeScript-first - Excellent documentation - Large ecosystem

Databases

SQL Database

Technology Version Purpose
PostgreSQL 8+ Primary relational database
Sequelize ^6.37.7 SQL ORM
sequelize-cli ^6.6.2 Migration management
pg ^8.15.6 PostgreSQL client

Data Stored: - Users and authentication - Services and categories - Orders and payments - Accounts and transactions - Configurations

Development Alternative: SQLite (sqlite3 ^5.1.7) for quick local setup

NoSQL Database

Technology Version Purpose
MongoDB ^8.17.0 Document database
Mongoose ^8.17.0 MongoDB ODM

Data Stored: - Chat messages - Real-time communication data

Why MongoDB for Chat? - Flexible schema for different message types - High write throughput - Natural fit for real-time data

Caching

Technology Version Purpose
Redis 5+ In-memory cache
@redis/client ^5.0.1 Redis Node.js client

Use Cases: - Session storage - Rate limiting - Notification count caching - Temporary data storage

Validation & Schema

Technology Version Purpose
Zod ^3.24.3 Schema validation

Why Zod? - TypeScript-first - Composable schemas - Excellent error messages - Zero dependencies

Example: 

const userSchema = z.object({
  email: z.string().email(),
  fullName: z.string().min(2),
});

Real-Time Communication

Technology Version Purpose
Socket.io ^4.8.1 WebSocket library
@nestjs/websockets ^11.1.4 NestJS WebSocket support

Features: - Real-time chat - Order status updates - Notifications

State Management

Technology Version Purpose
XState ^5.20.1 State machine library

Why XState? - Explicit state transitions - Prevents invalid states - Visualizable workflows - Predictable behavior

Used For: - Order workflow management - Complex business processes

Authentication & Security

Technology Version Purpose
jsonwebtoken ^9.0.2 JWT implementation
bcryptjs ^3.0.2 Password hashing

Security Features: - JWT-based authentication - Bcrypt password hashing - Role-based access control (RBAC) - Permission system

File Handling

Technology Version Purpose
Multer (via NestJS) File upload middleware

Storage: - Local filesystem - Easily extendable to S3/Cloud Storage

Email

Technology Version Purpose
Nodemailer ^7.0.3 Email sending

Features: - Welcome emails - Order notifications - Account verification - Password reset

Payment Processing

Technology Version Purpose
Axios ^1.12.2 HTTP client

Gateway: Paystack (easily extendable to other providers)

Features: - Payment initialization - Webhook handling - Payment verification - Refunds

API Documentation

Technology Version Purpose
Swagger 11.1.6 API documentation
@nestjs/swagger 11.1.6 NestJS Swagger integration

Access: /docs/swagger-ui

Features: - Interactive API testing - Auto-generated from code - Request/response schemas

Testing

Technology Version Purpose
Jest ^29.7.0 Test framework
ts-jest ^29.3.2 TypeScript Jest transformer
@faker-js/faker ^9.8.0 Test data generation

Test Types: - Unit tests - Integration tests - Repository tests - Use case tests

Code Quality

Technology Version Purpose
ESLint ^9.27.0 Linting
Prettier ^3.5.3 Code formatting
TypeScript ESLint ^8.32.1 TypeScript linting

Utilities

Technology Version Purpose
@paralleldrive/cuid2 ^2.2.2 Unique ID generation
decimal.js ^10.6.0 Precise decimal arithmetic
reflect-metadata ^0.2.2 Metadata reflection (required by NestJS)
rxjs ^7.8.2 Reactive programming

Why Decimal.js? - Financial calculations require precision - Avoids floating-point errors - Essential for money operations

Scheduled Tasks

Technology Version Purpose
@nestjs/schedule ^6.0.0 Cron jobs

Use Cases: - Auto-reject expired orders - Auto-complete valid orders - Periodic cleanup tasks

HTTP Client

Technology Version Purpose
@nestjs/axios ^4.0.1 HTTP client module
Axios ^1.12.2 Promise-based HTTP client

Development Tools

Technology Version Purpose
ts-node ^10.9.2 TypeScript execution
@nestjs/cli ^11.0.6 NestJS CLI tools
nodemon (via NestJS) Auto-restart on changes

Deployment

Technology Version Purpose
Docker - Containerization
Docker Compose - Multi-container orchestration

Container Features: - Multi-stage builds - Production-optimized - Alpine-based (small image size)

Architecture Decisions

Why PostgreSQL?

  • ACID compliance: Critical for financial transactions
  • Relational data: Users, orders, services have clear relationships
  • Mature ecosystem: Battle-tested, reliable
  • Complex queries: Advanced joins and aggregations

Why MongoDB for Chat?

  • Flexible schema: Different message types
  • Horizontal scaling: Growing message volume
  • Document model: Natural fit for messages

Why Redis?

  • Speed: In-memory operations
  • Simple data structures: Key-value, lists, sets
  • TTL support: Auto-expiring data

Why Sequelize?

  • Mature ORM: Well-documented
  • Migration support: Database version control
  • TypeScript support: Type-safe queries
  • Multi-dialect: Works with PostgreSQL, MySQL, SQLite

Version Requirements

Technology Minimum Version Recommended
Node.js 22.0.0 Latest v22.x
PostgreSQL 12.0 Latest stable
MongoDB 6.0 Latest stable
Redis 6.0 Latest stable
pnpm 8.0 10.7.1+

Next Steps