Senior Backend Developer (TypeScript + NestJS + AWS)

Qulix Systems; Wrocław; Hybrid; PLN 180,000 - 260,000; Full time

Job summary

Qulix Systems is seeking a Senior Backend Developer (TypeScript + NestJS + AWS) in Poland/Europe to own delivery of central platform services and drive ongoing modernization of the architecture.

You will build features, dive into legacy code, and take operational responsibility for your services, ensuring stability and ongoing improvements across the stack. The role emphasizes pragmatic problem solving and cloud/DevOps proficiency.

Qualifications

• Senior-level expertise in TypeScript, NestJS, and AWS.
• Experience with production cloud systems and troubleshooting.
• Proven track record migrating legacy code to modern architectures.
• Able to take end-to-end ownership of services.

Responsibilities

• Build new features and backend services while modernizing legacy architectures.
• Dive into existing code to understand, support, and upgrade it.
• Take operational ownership and analyze production systems for stability.
• Independently troubleshoot production applications and resolve issues.
• Propose architectural and process improvements.

Skills

TypeScript

NestJS

AWS

DevOps practices

Job description

Senior Backend Developer (TypeScript + NestJS + AWS)

Level: Senior, Middle

Location: Poland, Europe

• TypeScript
• NestJS
• AWS

We are looking for a skilled Middle+/ Senior Backend Developers to join our team and take delivery responsibility for the further development and operation of a central platform services within the Global Accounting environment.

This role offers the challenge of working with a real-world, established ecosystem. Your scope will include a balance of maintaining legacy services, building new features, and driving the sustainable modernization of its architecture.

We value a pragmatic approach, technical curiosity, and an operational mindset.

What You Will Do:

• Build new features and backend services while sustainably modernizing historically grown architectures.
• Dive into existing legacy code to understand, support, and successfully upgrade it.
• Take operational responsibility for your services, analyzing production systems and ensuring their stability.
• Independently troubleshoot production applications and resolve technical challenges.
• Actively contribute architectural and process improvement proposals.

Must-Haves:

• High seniority level in TypeScript, NestJS, and AWS.
• Practical experience with production cloud systems, DevOps practices, and application troubleshooting.
• Proven track record of working with legacy code, reverse engineering, and migrating older systems to modern standards.
• A realistic, solution-oriented approach to complex, historically grown software architectures.
• Experience taking full end-to-end ownership of existing services.

Nice-to-Have:

• Experience or basic skills in React to help with minor full-stack tasks when needed.