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 Middle Full-Stack Engineer (.NET + React) to join a project for our US-based partner, a digital healthcare company providing remote cardiac monitoring solutions for clinics and hospitals. The engineer will work on a web-based application that enables healthcare professionals to manage patient monitoring studies and access clinical information. You’ll contribute to both the .NET backend and React-based frontend, developing new functionality, improving existing features, and supporting the security, reliability, and scalability of the product. Your team : You’ll join a cross-functional team of .NET developers, QA engineers, an Automation QA Engineer, and a Team Lead. You’ll work closely with the team on developing and improving the product. Core technology stack: Backend: C#, .NET, ASP.NET Core, Entity Framework Core Frontend: React, JavaScript, HTML5, CSS3 Architecture & data: REST APIs, microservices, MS SQL Server, PostgreSQL Integration & security: AWS SQS; RabbitMQ/Kafka; OIDC, SSO, API security Cloud & delivery: AWS (ECS, Fargate, EC2, Lambda, S3), Docker, CI/CD Your responsibilities: Develop and maintain features across .NET backend services and a React-based web interface. Build reusable UI components and integrate them with REST APIs. Develop and maintain REST APIs, integration services, and scalable, stateless backend components. Work with MS SQL Server, PostgreSQL, and Entity Framework Core. Implement and support asynchronous service communication using message queues such as AWS SQS, RabbitMQ, or Kafka. Apply secure development practices, including authentication/authorization, OIDC/SSO, and API security. Work with AWS-hosted services and support Docker-based deployments and CI/CD pipelines. Investigate and resolve issues across the frontend and backend. Participate in code reviews and technical discussions. Collaborate with developers, QA engineers, and project stakeholders. Maintain relevant technical documentation. Contribute to the security, reliability, scalability, and maintainability of the application. It's about you: 3+ years of professional experience with C# and .NET Strong practical experience with ASP.NET Core, REST APIs, Entity Framework Core, and microservices Hands-on commercial experience with React and JavaScript Component-based UI development and frontend/API integration Working knowledge of HTML5, CSS3, and responsive web interfaces Solid SQL skills and experience with relational databases, including MS SQL Server and PostgreSQL Hands-on experience with AWS-based applications Hands-on experience with containerization Experience with integrations and message queues Understanding of asynchronous communication Understanding of authentication/authorization, OIDC/SSO, secure coding, and API security Ability to translate requirements into technical solutions Clear communication, problem-solving skills, and ownership How to join: Pre-screening with a recruiter Expert review of your resume English check Interview with our experts Customer 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!