Job Description – Windows Developer (C#)

A trusted VPN service provider is looking for a passionate and driven Windows Developer (C#) who is confident in coding, understands networking and Windows application development, and is eager to build real-world software products used globally.

Products You Will Help Develop

• https://www.bullvpn.com/

• https://www.vpn4games.com/

• https://www.uppervpn.com/

About the Company

We develop VPN solutions that enhance internet security and privacy for users worldwide. Our platforms serve customers in Thailand and internationally, with more than 800,000 users globally.

We are committed to continuous technology improvement, aiming to deliver better products and expand into global markets.

We are looking for energetic, creative individuals who are willing to share ideas, learn, and grow alongside the team. If you believe you have the capability, we welcome you to join the conversation anytime.

Why Join Us

• Monday–Friday working hours: 10:00 – 18:00 (flexible start/end time)

• Hybrid work model: 3 days office / 2 days WFH

• Annual company trip

• Social security

• Health and life insurance

• Regular team gatherings

• Snacks, beverages, and coffee provided

• Internal training programs and external training opportunities

• Performance-based bonus aligned with company results and individual performance

Key Responsibilities

• Develop and maintain Windows applications using C# and .NET Framework

• Design and build modern, user-friendly UI/UX using WinForms, WPF, or WinUI

• Collaborate with the team to develop new features for the Windows VPN client

• Implement networking functionality such as VPN, proxy, and socket connections

• Integrate and manage web services for data exchange with servers

• Debug, fix issues, and maintain production software

• Optimize application performance (speed, memory usage, stability)

• Maintain a secure auto-update system for application deployment

• Work effectively with other developers in a collaborative environment

Qualifications

• At least 1 year of experience in Windows application development, or demonstrable real-world application projects

• Proficient in Git with portfolio or projects showcasing your work

• Strong sense of ownership, quality focus, and teamwork skills

• Basic understanding of VPN, networking, or internet privacy is a plus

• Understanding of software business and IT systems is advantageous

• Leadership potential, positive mindset, ability to work under pressure, and strong problem-solving skills