About us : Techstack is a technology product engineering company that sets an example for high development standards in the IT industry. We empower each team member to influence the development of the product, company, and processes. About the product : We are looking for a Senior Backend Software Engineer (Node.js) to join a long-term project for our Canadian partner, an international software company with a portfolio of Windows products distributed under multiple brands. The project involves a large, interconnected ecosystem of applications and services built and maintained over many years. It combines legacy systems with modern cloud-based solutions and includes backend services, administrative platforms, APIs, websites, integrations, and internal tools supporting product distribution, marketing, and operations. You’ll work on maintaining production stability, investigating complex technical issues, improving existing systems, and gradually modernizing the technical environment. Technology stack :

Backend: Node.js, TypeScript, JavaScript, PHP (legacy), C# (limited exposure) Databases: MySQL, PostgreSQL, MongoDB, Amazon Aurora, Amazon DocumentDB Cloud & Infrastructure: AWS, AWS Lambda, Serverless Framework, API Gateway, Load Balancers, AWS Secrets Manager, AWS SDK Messaging & Caching: RabbitMQ, Amazon SQS, Redis DevOps & Deployment: Docker, Terraform, CI/CD, PM2, Serverless deployments Legacy Frontend: AngularJS v1 AI-assisted Development: GitHub Copilot, Cursor, Claude Code, or equivalent tools

Your team : You’ll join a small, experienced Techstack team supporting a diverse backend ecosystem. You’ll work closely with a Senior Engineer who has deep knowledge of the systems, another Senior Engineer involved part-time, and a Project Manager on the client side. The role offers plenty of independence, ownership, and opportunities to explore complex systems, share knowledge, and make a real impact on their stability and improvement. Your responsibilities: Support and enhance backend services, APIs, admin portals, websites, and automation tools. Maintain, troubleshoot, and gradually modernize existing applications across legacy and modern technologies. Investigate production issues and perform root-cause analysis. Work with AWS infrastructure, cloud services, and deployment pipelines. Improve system stability, maintainability, and performance. Investigate unfamiliar systems and help recover or improve technical documentation. Use AI-assisted development tools for coding, debugging, testing, refactoring, and documentation. Review and validate AI-generated code for quality, security, and maintainability. Collaborate with the existing team and client-side stakeholders during onboarding and knowledge transfer. Take ownership of assigned components and contribute to reducing technical debt. It’s about you: 5+ years of commercial software development experience. Strong hands-on experience with Node.js, TypeScript, and JavaScript. Experience building and supporting REST APIs and distributed systems. Strong SQL skills and experience with relational databases. Confident hands-on experience with AWS and cloud infrastructure. Experience troubleshooting production systems and working with legacy applications. Good understanding of software architecture, design patterns, security, and system integrations. Ability to work independently with complex, poorly documented systems. Practical experience using AI-assisted development tools such as GitHub Copilot, Cursor, Claude Code, or similar in everyday development. Ability to use AI tools to accelerate development, debugging, testing, refactoring, documentation, and codebase investigation while critically reviewing the generated output. Strong sense of ownership, attention to detail, and a pragmatic approach to problem-solving. How to join: Pre-screening with a recruiter English check Techstack internal technical interview Techstack PM interview Client interview Culture: At Techstack, we care about how we build products — not only about the result, but also about the quality of the engineering process and the way we work together. We encourage people to keep learning, share what they know, and take ownership of their work. Tech Guilds — communities where specialists share knowledge, discuss technical solutions and approaches, and keep up with industry trends. Meetups and knowledge sharing — opportunities to share your experience with colleagues and the wider tech community. Mentoring and leadership — opportunities to grow as a mentor, technical lead, or take on other roles where you can support others and share your expertise. We believe that good products come from people who care about what they build, keep developing their expertise, and are comfortable both challenging ideas and being challenged. What we have for you: Flexible work format — remote work or one of our hubs in Kyiv, Lviv, Kharkiv, or Wrocław, plus flexible working hours. Professional growth — Tech Guilds, mentoring, meetups, knowledge sharing, and other development opportunities. Education support — 50% compensation for professional courses, trainings, webinars, and certifications. English — free General English, Business English, and speaking clubs. Time off — 20 paid days off and 7 paid sick days per year, plus additional days off. Support — legal and accounting support. Community — online and offline team activities, professional events, and appreciation gifts. See yourself in this role? Send us your resume and let’s start the conversation!