Holisticon Insight is a division of http://nexergroup.com focused on IoT, AI, and advanced analytics. We assist our customers in developing IoT services, portals, and mobile apps and, above all, analyze data using AI and advanced analytics to reduce costs, streamline, and find new opportunities for the business. Our goal is to grow strong but rather in competencies than in numbers. We get things done and, on the way, we build a dynamic company culture to create the best place for our development. We love the atmosphere of a family business with its flat structure and self-organized teams where every opinion matters and influences our way of working. Check us out!👇https://holisticon.pl/holisticon-insight/📍 In-office work | B2B: 140–170 PLN/h net + VATWe are looking for a skilled .NET Developer to join our client’s cross-functional team working on the development of a core enterprise solution and related systems. You will be responsible for the entire lifecycle of the solution — from business requirements and system analysis to implementation, enhancement, and maintenance.You’ll collaborate closely with architects, analysts, and testers to design high-quality software components, continuously improve processes and tools, and ensure smooth delivery within an Agile framework.⚡ Must have: Deep knowledge of .NET / C#. Strong experience with WPF (Windows Presentation Foundation). Solid understanding of SQL (queries, design, optimization). Experience with NHibernate or Entity Framework. Proficiency with XML and JSON. Experience using Visual Studio, SQL Management Studio, and Azure DevOps. Strong commitment to S.O.L.I.D. principles and Clean Code practices. Good command of English (proficiency preferred). Ability to work from the office (it's not a remote/hybrid position!) ✅ Nice to have: Familiarity with DevOps practices (e.g. YAML pipelines, WiX toolset). Understanding of microservices and cloud solutions (especially Azure). Experience with ASP.NET MVC. Background in Test-Driven Development (TDD) or Test First Programming. 🎯 Your responsibilities: Develop and implement new features and modifications in existing .NET-based applications. Design and maintain code with a strong focus on quality and testability (unit, integration, and UI functional tests). Participate in business requirements analysis and provide technical expertise during solution design. Collaborate closely with architects, testers, and analysts to deliver well-structured epics and stories. Promote continuous improvement of development practices, automation, and agile methods. By joining Holisticon Insight you will get: Life insurance Multisport card Private medical care Flexible working hours Amazing integration events on a regular basis Training budget (e.g. Microsoft Azure Certifications) Opportunity to impact our company culture build-up Work equipment (laptop, 2 monitors, and accessories) Recruitment process: Screening call with Holisticon Insight recruiter (30 min) Technical interview with team representative (45–60 min) Recruitment task Code review (30 min) Final meeting with Product Owner / client (45–60 min)