Join the product development organization behind an established business-software product, working alongside its existing team as an external developer on a focused, project-based engagement.In this role, you will:

• Develop and maintain product functionality using VB.NET/.NET Framework alongside modern C# on .NET Standard 2.0 / .NET 8+, working across both legacy and current parts of the codebase.
• Work with SQL for data access and logic, and HTML, CSS, and JavaScript on the front end.
• Apply AI-native development methods and practices as part of day-to-day work, using the AI tooling the client provides.
• Support and coach more junior team members as a senior presence on the team, not just as an individual contributor.
• Collaborate closely and communicate effectively as part of an established product team, getting things done efficiently.
• Work primarily remotely, with occasional in-person meetings at the client's Helsinki or Lappeenranta office (travel expensed).

You will thrive if:

• You're a senior developer with strong, hands-on experience across VB.NET/.NET Framework and modern C#/.NET (Standard 2.0 and/or .NET 8+), comfortable moving between both.
• You have solid SQL skills and working knowledge of HTML, CSS, and JavaScript.
• You have real experience with AI-native/AI-assisted development methods, not just familiarity with the concept.
• You're an effective communicator and team player who can support and mentor less experienced developers.
• Prior experience with payroll/HR functionality or financial management software is a plus, though not required.
• You're fluent in both Finnish and English.
• You can start around mid-October and commit to an initial ~2–3 month engagement (suggested period mid-October through year-end).