Senior .NET Developer

Who are we?

Founded in 2001, MobiSystems is a Bulgarian software company dedicated to empowering users with a better choice for office suite apps. Our feature-rich tools like MobiOffice and MobiPDF, offer a seamless, privacy-conscious, and affordable alternative to traditional office suite software for Windows, Android, iOS, and macOS.

Trusted by over 550 million users worldwide, MobiSystems is committed to delivering accessible, cost-effective solutions that make work and personal tasks easier. Our headquartered in Sofia with a team of 200 and we have a sales office in San Diego, CA.

What are we looking for?

We are currently seeking an experienced .NET/C# Developer to join our Windows platform team and contribute to the development of our Windows applications. You will be responsible for creating a seamless user experience, delivering high-quality and efficient code for our desktop software, analyzing, optimizing, and refactoring existing code to improve performance and maintainability, and collaborating with cross-functional teams to define, design, and implement new features and enhancements.

Requirements:

• 5+ years of professional experience in .NET/C# software development.

• Deep proficiency in Software Architecture and Object-Oriented Design (OOD) (SOLID principles, Design Patterns, Dependency Injection).

• Passion for writing good code combined with a strong ability to produce clean, maintainable, and testable solutions.

• Fluent use of AI tools as part of your workflow

• Be able to critically evaluate, verify and own AI generated/assisted code

• Fast learner willing to adapt to the Windows desktop environment (including WPF), with a focus on core application logic rather than just UI.

• General understanding of Desktop application programming concepts (e.g., state management, UI threading models, event-driven programming).

• Good understanding of C# asynchronous programming, multi-threading, and memory management.

• Strong understanding of algorithms, data structures, and performance optimization techniques.

• Strong communication skills & willingness to work in a team.

Nice to have:

• Experience with C++, WinRT, or WinAPI is a big plus.

• Previous experience with WPF, WinForms, or other Desktop UI frameworks.

• Degree in Informatics, Computer Science, Engineering, or equivalent.

What do we offer?

• Working on inspiring products in a team of supportive professionals

• Compelling salary and regular performance assessment with salary review

• Work at the Headquarters of a product company and have a say in the direction of its products

• A great location - right next to a metro station, Paradise Center and the best park in Sofia

• Work from the office, with the option of working from home two days per week

• Opportunities for professional growth and freedom to make an impact

• Multiple secondary benefits: additional health insurance with dental care coverage, sport program, corporate discounts, 25 days paid yearly leave + additional days off, etc.