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April 8, 2026

Senior Fullstack Engineer

Senior • Remote

4,500 - 5,600 USD

Krakow, Poland

We are looking for a Senior Full-Stack Engineer to join our team, Our customer is the European online car market with over 30 million monthly users, with a market presence in 18 countries. As a Senior Fullstack Engineer, you will play a pivotal role in shaping the future of online car markets and enhancing the user experience for millions of car buyers and sellers.

Responsibilities:

  • Design and develop full-stack cloud solutions from technical analysis to integration testing.

  • Support existing systems

  • Mentor junior engineers on design patterns, code reviews, testing practices, and scalable architecture.

  • Establish documentation standards across teams.

  • Conduct root cause analysis and collaborate with production support to resolve issues.

  • Evaluate third-party software with business and engineering teams.

  • Maintain CI/CD pipelines for applications.

Requirements:

  • Canadian timezone work hours (EDT)

  • 4+ years of experience with C# or .NET  for web application development

  • 4+ years of experience with React for web application development

  • Experience with Azure, including migration from Azure to AWS

  • Expert proficiency in GenAI-driven development, GitHub Copilot/Codex integration, rapid prototyping, automated refactoring, and AI-accelerated debugging

  • Deep understanding of AI agents, autonomous task orchestration, reasoning engines, tool-use integration, and multi-step workflow automation

  • Mastery of iterative prompting. Chain-of-Thought (CoT), Few-Shot prompting, output validation, and prompt optimization for production-grade code

  • Familiarity with Kafka, SQL, and performance optimization

  • Strong understanding of event-driven and microservices architecture

  • Experience, Application Insights, and responsive front-end design using React

  • Background in high-traffic websites, performance tuning, and security

  • Ability to communicate technical solutions effectively

  • Expertise in unit, component, and integration testing

  • Experience with Azure DevOps, and JIRA in distributed teams

  • Solid grasp of agile methodologies, including ScrumBan/Kanban and Gitflow

Nice to Have:

  • Previous DevOps Experience is a great advantage

  • Experience with Java and Scala

  • Experience with observability tools like Datadog

  • Proficiency with  Java/Spring Boot for building APIs and web applications - nice to have

  • Experience with AWS

  • Previous experience with GitHub

This job opportunity for Canadian time zone.