Senior Backend Engineer – JD

Job Description

Employment Type: Full-time
Work Model: Remote
Location: Bucharest, Romania

Role Overview

We are hiring a Senior Backend Engineer to design, build, and operate scalable backend systems that support real-time feeds, chat, payments, and high-volume user activity. This role focuses on building reliable, secure, and high-performance APIs that operate under sustained load.

The stack is centered around NestJS with Node.js and TypeScript, MongoDB, Redis, and AWS, with strong emphasis on observability, API discipline, and security-by-design.

Technology Stack

• Node.js, TypeScript
• NestJS
• MongoDB
• Redis
• AWS
• OpenTelemetry observability
• REST APIs and WebSockets
• OpenAPI and Swagger documentation
• API versioning, rate limiting, and pagination

Responsibilities

• Design and build robust backend services using NestJS, including guards, interceptors, pipes, and global validation
• Implement contract-first APIs with strong OpenAPI and Swagger discipline
• Build secure authentication and authorization flows using JWT and role-based access control
• Optimize MongoDB performance through indexing, aggregation pipelines, and concurrency-safe data access patterns
• Use Redis for caching, queues, and rate limiting
• Ensure system reliability, performance, and correctness under high load and real-time traffic
• Apply secure coding practices aligned with OWASP guidelines and abuse-prevention principles
• Maintain clear technical documentation and contribute to code quality and architectural standards

Required Skills and Experience

Backend Engineering

• Strong hands-on experience with TypeScript and NestJS in production environments
• Proven experience designing and operating scalable backend architectures
• Solid understanding of REST APIs and WebSockets
• Experience with API versioning, pagination, and rate-limiting strategies

Data and Distributed Systems

• Strong MongoDB experience, including indexing strategies and aggregation pipelines
• Practical experience using Redis for caching, queues, and distributed coordination

Security and Reliability

• Hands-on experience implementing authentication and authorization using JWT and role-based access
• Awareness of OWASP security principles and common abuse or attack patterns
• Experience building backend systems that remain stable and secure under load

Cloud and Observability

• Experience deploying and operating backend systems on AWS
• Familiarity with observability tooling, including metrics, tracing, and logging
• Experience monitoring, debugging, and optimizing production systems