Back-end developer

Kassavirtanen Oy; Helsinki; On-site; EUR 55,000 - 75,000; Full time

Benefits offered by this job

Competitive salary

Modern Kamppi office

Supportive team

Career growth

Job summary

Kassavirtanen Oy in Helsinki seeks a Back-End Developer who enjoys building scalable services. You will design and implement back-end systems and REST APIs powering our platforms, working with front-end developers to deliver smooth user experiences.

Required: 2+ years with C# / .NET and SQL, writing clean, maintainable code, and contributing to architecture. Git experience and a willingness to learn are essential in our collaborative, modern Kamppi office.

Qualifications

• 2+ years of back-end development experience.
• Strong knowledge of C# / .NET and SQL databases.
• Experience designing and building REST APIs.
• Write clean, efficient, maintainable code.
• Experience with Git version control.
• Understanding of architecture and scalability.
• Fluent in Finnish or English.

Responsibilities

• Design and implement back-end services powering our systems.
• Build APIs for web services and client projects.
• Collaborate with front-end developers and designers.
• Ensure code quality and maintainability.
• Contribute to DevOps and cloud deployment practices.

Skills

Back-end development

C# / .NET

SQL databases

REST APIs

Git

Software architecture

Teamwork

English or Finnish

Tools

Azure/AWS

Job description

Who we are

Kassavirtanen Oy is a growing invoicing service company that designs and develops its own systems, websites, and digital services for businesses. We operate from a modern office in the heart of Helsinkis Kamppi district, where teamwork and open communication are at the core of everything we do.

We focus on high-quality code, long-term development, and understanding our clients’ businesses. You will have the opportunity to work on meaningful projects that matter to us and our clients.

Your role with us

We are now looking for a Back-End Developer who is passionate about building scalable and efficient back-end systems.

You will work as part of our development team, designing and implementing back-end services and APIs that power both our own systems and custom web services for our clients. In collaboration with front-end developers and designers, you will help build powerful solutions that provide smooth and seamless user experiences.

Technologies we use:

• C# / .NET – for back-end development
• SQL – working with databases and integrations
• JavaScript – basic knowledge for handling API integration and client-side logic
• REST APIs – building and maintaining APIs for web services and systems
• Familiarity with cloud platforms (Azure, AWS) and DevOps practices is a plus

What we expect from you:

• Previous experience in back-end development (at least 2 years)
• Strong knowledge of C# / .NET and SQL databases
• Experience with designing and building REST APIs
• Ability to write clean, efficient, and maintainable code
• Experience working with version control (Git)
• Understanding of application architecture and scalability
• Teamwork skills and a willingness to learn
• Fluent in Finnish or English

What we offer you:

• Interesting projects with the opportunity to influence their implementation
• A supportive work environment and colleagues who will help you grow
• A modern workspace in a cozy office in the heart of Kamppi
• A competitive salary and excellent employee benefits

Osaamisalue:

IT & tietoliikenne