.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 the company.

• 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).