.NET WinForms Developer

We are looking for an experienced .NET WinForms Developer to join the frontend engineering team and help build high-performance, real-time trading applications used by professional traders.  This role is not about configuring UI frameworks - it is about crafting fast, responsive, custom-rendered desktop UI.  IN SHORT: 🌎 100% remote or from the office (Wrocław, Bielsko-Biała) - You choose! 💰 125 - 140 PLN/h ☑️ B2B contract 💻 >5 years of commercial programming experience Your Daily Missions • Design, implement and optimize custom WinForms controls (charts, grids, interactive visualization components).  • Work with continuous real-time data streams and ensure ultra-responsive UI under load.  • Ensure smooth multi-threaded UI updates without blocking or freezing.  • Collaborate with backend engineers (C++ systems) to maintain low-latency TCP/socket communication.  • Profile, debug, and tune rendering performance (GC pressure, paint cost, batching, flicker control).  • Improve engineering practices, and influence UI architecture and usability.    The Essentials We're Seeking  • 5+ years of hands-on experience developing desktop applications in C#/.NET (preferably .NET 8).  • Strong expertise in Windows Forms.  • Proven experience building custom UI controls from scratch (inheriting from base controls and implementing custom rendering - not configuring DevExpress/Telerik/Infragistics).  • Experience working with continuous real-time data streams, where data is pushed to the UI (not periodic refresh).  • Strong understanding of multi-threaded UI applications (updating UI safely from worker threads, avoiding freezes and stalls).  • Practical experience in UI performance optimization (reducing redraw cost, minimizing GC pressure, batching updates, preventing flicker).  • Experience working with TCP / socket-based communication.  • Ability to clearly explain previous UI design decisions, trade-offs, and the impact on end users.  • Fluency in English (minimum B2+).    Nice to Have  • Experience with trading systems, market data, or real-time financial applications.  • Familiarity with C++ or interoperability between C# and native components.  • Understanding of high-performance visualization and data interaction patterns.  Reasons Why You Would Enjoy Working With Us • We work in the latest technologies and with international clients, and our projects are polished from < to /> - learn about some of the projects we have completed. • We organize TechTalks, meet-ups and create guilds where we exchange knowledge - you can learn a lot from your teammates. • We have a close-knit team and we make sure to have regular integrations - we often go out to celebrate together. • You can work remotely or choose to work from our offices in Wroclaw or Bielsko-Biala. However, we count on your openness to occasionally visit the office for team meetings or client visits, or possible occasional trips to the client's headquarters. • You can adjust your working hours to suit your needs, starting your day between 7:00 and 10:00 am. • You can work with great specialists in their fields who also have a sense of humor and other after-hours hobbies. It is the people who create the unique atmosphere and relaxed atmosphere at CSHARK. • We have a flat structure - we are not a corporation and don't want to be one 🙃. • We offer bonuses for employee referrals (from 3000 PLN to 7000 PLN). • We organize remote English classes and provide access to the company library. You can also become an author/author of articles published on our technical blog - https://cshark.com/blog/.