Backend Developer Job Description
Company Overview
We are seeking a skilled Backend Developer to join our team working on NXmarket/Nexstox, a comprehensive RWA exchange and Launchpad platform built with modern microservices architecture. Our platform manages multiple business domains including cryptocurrency trading, wallet management, product launches, token staking, gaming systems, and external exchange integrations.
Position: Backend Developer
Key Responsibilities
Core Development:
- Design, develop, and maintain high-performance microservices using TypeScript/Node.js and Spring Boot/Kotlin
- Build and optimize RESTful APIs with comprehensive validation using Zod schemas and Jakarta validation
- Implement multi-layered authentication systems (JWT, API keys, 2FA/TOTP) with role-based access control
- Develop real-time features using WebSockets for trading platforms, gaming, and live market data
- Create and maintain database schemas and optimize queries for MongoDB, PostgreSQL, Redis, and InfluxDB
Business Domain Expertise:
- Cryptocurrency Exchange: Order matching, trading engine, wallet management, deposits/withdrawals
- Financial Security: Multi-stage approval workflows, KYC/AML compliance, transaction monitoring
- E-commerce Platform: Product management, order processing, revenue distribution
- Gaming Systems: Betting mechanics, statistics tracking, reward distribution
- External Integrations: Binance API, CryptoAPIs, wallet providers (Safeheron), automated synchronization
- Financial Operations: Multi-currency support, balance management, profit calculations, referral systems
Technical Architecture:
- Work within a monorepo structure using pnpm workspaces and Turbo for Node.js services
- Implement microservices communication and shared package management
- Design Redis-based configuration, caching, and real-time messaging systems
- Build scheduled job systems using cron for automated data synchronization
- Develop comprehensive error handling, logging, and monitoring systems
- Integrate with AWS services (S3, SES, ECS, ECR) for cloud infrastructure
Required Technical Skills
Core Technologies:
- Node.js (v18+) with TypeScript (5.3.3) in strict mode
- Java 21 with Kotlin (1.9.20) for Spring Boot services
- Spring Boot 3.2.4 with Spring Security, Spring Data JPA, Spring WebSocket
- Fastify 4.x framework with plugin architecture
- MongoDB (6.6.1) with official driver and transaction support
- PostgreSQL with node-postgres and JPA/Hibernate
- Redis (ioredis) for caching, configuration, and real-time messaging
- InfluxDB for time-series data and analytics
- JWT authentication with role-based access control and 2FA/TOTP
Development Tools:
- pnpm (10.10.0) for Node.js package management
- Gradle for Java/Kotlin build management
- SWC for fast TypeScript compilation
- Jest (29.7.0) and JUnit 5 for testing with >80% coverage target
- ESLint and Kotlin Lint with shared configuration for code quality
- Bruno for API testing and documentation
- Nodemon and Spring Boot DevTools for development hot reloading
Validation & Security:
- Zod 3.x for Node.js request/response validation and type safety
- Jakarta Validation and javax.validation for Spring Boot validation
- bcrypt for password hashing
- SHA256 encoding for secure data processing
- Google Authenticator (TOTP) for 2FA implementation
- Input validation and sanitization
- HTTPS transmission and token expiration handling
- API key authentication and rate limiting
Required:
- 3+ years of backend development experience
- Strong proficiency in TypeScript/Node.js OR Java/Kotlin/Spring Boot
- Experience with Fastify, Express, or Spring Boot web frameworks
- Database experience with MongoDB and/or PostgreSQL
- Understanding of RESTful API design principles
- Experience with testing frameworks (Jest, JUnit preferred)
- Knowledge of authentication and security best practices
Preferred:
- Experience with microservices architecture and distributed systems
- Knowledge of cryptocurrency and blockchain technology
- Experience with Redis, caching strategies, and real-time messaging
- Background in financial services, fintech, or e-commerce applications
- Experience with monorepo management and build tools
- Understanding of JWT, OAuth2, and multi-factor authentication
- Experience with Docker, AWS, and cloud deployment
- Knowledge of financial compliance and security standards
- Experience with high-performance, low-latency systems
Benefits
- Competitive salary and benefits package
- Opportunity to work with cutting-edge technologies in fintech
- Collaborative and innovative work environment
- Professional development opportunities and conference attendance
- Flexible work arrangements
- Opportunity to work on high-impact financial technology
- Exposure to cryptocurrency and blockchain technologies
- Career growth in a fast-growing startup environment
