Senior Fullstack Engineer (ASP.NET / React)

O projekcie: We’re looking for a Senior Fullstack Engineer who brings deep technical expertise and a collaborative mindset to our product development team. You will work with a modern microservices architecture, building scalable backend services using theASP.NET Web API with C#, and intuitive frontend interfaces using mainly React and TypeScript. This is a hands-on engineering role with a 50/50 front-/backend focus, ideal for someone who takes ownership, thrives in a dynamic product team, and enjoys mentoring others - this role could easily become a Tech Lead role in a foreseeable future. If you’re passionate about designing high-impact software in a cloud-native environment, we’d love to hear from you. This Poland-based role offers remote flexibility, but we value in-person collaboration. Our team meets in Poland for at least one week each quarter, so we ask all applicants to be located in Poland. This is not a globally remote role - Poland residency is required. The contract form is Umowa o Pracę (brutto). esurance is a Swiss InsurTech offering a SaaS platform that connects SMEs, insurance providers, brokers, and business application providers. Founded in 2013, we’re on a mission to make health insurance for small businesses truly hassle-free. What makes us unique You’ll be part of a connected, forward-thinking team built on trust, openness, and mutual respect — working hybrid from Zürich or remotely across Europe. We invest in your growth through agile practices, real ownership, and a transparent Grading System that ensures fair pay and clear career paths. Our core values - We are connected. - We are ahead. - We are clear. - We are approachable. Do these resonate with you? → Come join us. Use of Artificial Intelligence (AI) We use AI to increase productivity and you’re welcome to use it to polish your CV or Coverletter. Interviews and assessments should reflect your genuine self, though. Wymagania: Essential Qualifications: - 5 years of proven experience in building secure REST APIs using ASP.NET, as well as developing solid front-end applications with React are non-negotiable must haves. - Comprehensive knowledge of contemporary web application architectures, with a focus on microservices and cloud design patterns. - Demonstrated ability of high technical Ownership and Tech Leadership Bonus Skills: - Hands-on experience with AWS infrastructure. - Experience working in cross-functional product teams using Agile practices and following Domain-Driven Design (DDD). Collaboration and Interpersonal Skills: - Clear and adaptive communication with both technical and non-technical stakeholders. - Strong sense of ownership, accountability, and proactive problem-solving. Languages: - English (fluent) required - Ukrainian: desired, not required Codzienne zadania: - Collaborate proactively in refinement sessions with product and tech teams to ensure clarity and feasibility of features. - Design, implement, and maintain scalable web APIs using ASP.NET and microservices architecture principles. - Develop responsive user interfaces with React and TypeScript that enhance usability and performance. - Work closely with Product Owners to clarify feature requirements and ensure business context is well-understood. - Define and align feature architecture with the Head of Engineering to ensure consistency and scalability. - Ensure features meet Definition of Done, with appropriate unit, integration, and end-to-end test coverage. - Support incident response and production issue resolution as per team standards. - Actively contribute to team knowledge sharing and coach colleagues in technical best practices - potentially as a Tech Lead.