Tech Lead/Senior Node.js Backend Engineer (Infrastructure & High-Load Systems)

EasySoftGroup; Polska; Hybrid; PLN 300,000 - 460,000; Full time

Job summary

EasySoftGroup is seeking a Tech Lead/Senior Backend Engineer for a client at the intersection of fintech, AI, and digital asset infrastructure. You will join a highly skilled team building backend systems where scalability and reliability are critical.

Responsibilities include designing and maintaining Node.js/TypeScript services, APIs, and data models; working with MongoDB, Redis, and AWS; and shaping architecture for high-load, scalable platforms.

Qualifications

• Degree in Computer Science, Mathematics, or a related technical field.
• 7+ years of commercial backend development experience.
• Strong expertise in Node.js and TypeScript.
• Hands-on experience with MongoDB and Redis.
• Proven track record of building and supporting high-load production systems.
• Solid understanding of backend architecture, API design, and scalable system design principles.
• Hands-on experience with infrastructure setup, configuration, and support in cloud environments.
• Experience contributing to architectural decisions for scalable and reliable backend systems.

Responsibilities

• Design, develop, and maintain backend services using Node.js and TypeScript.
• Build and enhance APIs, data models, and core platform components.
• Work with MongoDB, Redis, and AWS cloud services.
• Design, build, and maintain high-load backend systems capable of handling large-scale traffic and ensuring high availability.
• Participate in the setup, configuration, and ongoing support of cloud infrastructure to ensure reliability, scalability, and operational efficiency.
• Contribute to improving deployment processes, monitoring, logging, and alerting for backend services and production environments.
• Troubleshoot and resolve production issues while ensuring system stability and performance.
• Optimize applications for scalability, reliability, and maintainability.
• Participate in technical discussions and contribute to architectural decisions around backend services, infrastructure, and platform scalability.

Skills

Node.js

TypeScript

Backend architecture

Cloud infrastructure

Debugging

Independence

Ownership

Education

Bachelor's degree in CS or related

Tools

MongoDB

Redis

AWS

Job description

We are looking for a Tech Lead/Senior Backend Engineer on behalf of our client, an innovative technology company operating at the intersection of financial technology, AI, and digital asset infrastructure.

This is an opportunity to join a highly skilled engineering team working on complex backend systems where scalability, reliability, and data integrity are critical. The role is best suited for engineers who enjoy solving challenging technical problems, taking ownership of their work, and contributing directly to the development of core platform functionality.

Responsibilities

• Design, develop, and maintain backend services using Node.js and TypeScript.

• Build and enhance APIs, data models, and core platform components.

• Work with MongoDB, Redis, and AWS cloud services.

• Design, build, and maintain high-load backend systems capable of handling large-scale traffic and ensuring high availability.

• Participate in the setup, configuration, and ongoing support of cloud infrastructure to ensure reliability, scalability, and operational efficiency.

• Contribute to improving deployment processes, monitoring, logging, and alerting for backend services and production environments.

• Troubleshoot and resolve production issues while ensuring system stability and performance.

• Optimize applications for scalability, reliability, and maintainability.

• Participate in technical discussions and contribute to architectural decisions around backend services, infrastructure, and platform scalability.

Requirements

• Degree in Computer Science, Mathematics, or a related technical field.

• 7+ years of commercial backend development experience.

• Strong expertise in Node.js and TypeScript.

• Hands-on experience with MongoDB and Redis.

• Proven track record of building and supporting high-load production systems.

• Solid understanding of backend architecture, API design, and scalable system design principles.

• Hands-on experience with infrastructure setup, configuration, and support in cloud environments.

• Experience contributing to architectural decisions for scalable and reliable backend systems.

• Strong debugging, troubleshooting, and problem-solving skills.

• Ability to work independently in a fast-paced environment.

Nice to Have

• Experience with distributed systems and event-driven architectures.

• Familiarity with messaging systems and asynchronous workflows.

• Previous experience in fintech, trading platforms, marketplaces, or other high-load systems.

• Startup or scale-up environment experience.

• Experience with CI/CD pipelines, containerization, or infrastructure automation tools

• Experience in competitive programming or participation in programming olympiads

We Value

• Strong ownership mentality.

• Attention to detail and focus on system reliability.

• Ability to identify edge cases and design robust solutions.

• Practical engineering mindset with a hands-on approach to development.

• Excellent communication and collaboration skills.