Fullstack Engineer

Department: Technology

Location: Serbia

Employment Type: FullTime

About billups

We don’t trade in hype. At billups, we’re reimagining how brands show up in the real world, literally. Powered by patented technology, proprietary AI, and a global team of 400+, we’re reinventing Out-of-Home (OOH) media to help brands connect with people in physical spaces, with more precision, intelligence, and impact than ever before. We move fast, think boldly, and collaborate deeply. Fiercely independent, with a presence in 20+ countries, we back smart ideas with data, technology, and trust. Growth is on the table, professionally and personally. We invest in talent and celebrate our people, plain and simple. Curious? Let’s talk.

What You'll Do

You will design, code, and support applications while solving problems and collaborating with team members in a highly technical environment. You’ll work across the full stack using .Net, ReactJS, SQL Server, and AWS technologies, performing application support, maintenance, troubleshooting, and debugging to ensure optimal performance. You’ll write clean, efficient code, develop unit, integration, and E2E tests, implement security best practices, and contribute ideas and research while sharing knowledge with the team. You’ll work in cross-functional teams to define, design, and ship new features, provide constructive feedback in code reviews, participate actively in team meetings, communicate challenges, and continue learning independently.

Essential Skills:

• Develop and deliver innovative solutions to our business including new services and features in modern apps using experience gained from previously developed legacy apps.

• Support and maintain applications and services to ensure smooth operation and reliable uptime.

• Demonstrate proper use of frontend and backend frameworks with low-latency and memory-efficient implementations.

• Write and maintain unit tests to release well-tested bug-free code.

• Create and maintain necessary technical documentation and artifacts.

What You'll Bring

• 3+ years of experience with C#/.Net based backend development.

• 3 or more years of experience in web development with a focus on React and TypeScript.

• Experience with test frameworks such as Jest, React Testing Library, Playwright, xUnit/NUnit, Moq.

• Strong knowledge of software development best practices and design patterns.

• Experience with Agile methodologies and working in a collaborative team environment.

• Experience with team development & source control (Git) and continuous integration/continuous delivery best Practices.

• Excellent communication and problem-solving skills, ability to work independently and manage multiple tasks.

• Experience with map API services like Google Maps or MapBox is a plus.

• Experience with database development (Microsoft SQL Server/Postgres) and AWS is a plus.

Total Rewards

• billups’ pay and benefits can vary by country, location, number of regularly scheduled hours worked, length of employment, and employment status.

• Well-being programs including medical, dental and vision benefits (varies by market).

• Generous 401(k) match program (USA) and pension schemes (global markets).

• Annual bonus plans.

• Equity grants (specific titles are eligible).

• Generous holiday and paid time off.

• Learning & Development offerings.

• Paid maternity leave and paternity leave (varies by country).