Medior Software Engineer (Backend/Integrations/.NET)

Are you a backend-focused developer who wants to grow into a medior role through real ownership? Do you enjoy improving existing systems, making them more reliable, testable, and future-proof? Are you motivated by security, privacy, and building software that actually matters? At Sendent, we’re looking for a Medior Software Engineer to take increasing ownership of our Exchange Connector and later contribute to our Outlook integration. You’ll work on real production software used by organizations that care deeply about data sovereignty and security. About Sendent Sendent is a fast-growing software company focused on privacy-first enterprise collaboration and communication. Our mission is to empower teams to secure their workflow effortlessly. We do so by building secure, user-friendly integrations between Microsoft tools and Nextcloud, enabling organizations to keep working with familiar software while retaining full control over their data. We believe in sustainable software, ownership, and trust; both in our products and in how we work together. You’ll join a growing, international team, working closely with experienced engineers and the founders in an environment where quality, autonomy, and learning are valued over speed for speed’s sake. Tasks What You’ll Work On Core Responsibilities Maintain and improve the Exchange Connector Take growing ownership over a critical backend product used in enterprise environments. Automated testing & quality improvements Write and improve unit, component, and integration tests to ensure stable, repeatable outcomes. Performance & reliability Think about threading, execution flow, and performance implications when designing or changing code. Research & problem solving Investigate unfamiliar code, technologies, or edge cases and translate findings into solid implementations. Gradual ownership of Outlook integration Over time, take responsibility for maintenance and improvements in our Outlook-related components. Requirements What We’re Looking For Must-Haves Professional experience with C# / .NET HBO or WO degree in Software Engineering, Computer Science, or similar 2–4 years of experience as a software engineer (junior growing toward medior) Backend-focused mindset (full-stack experience is fine, but not required) Experience maintaining or improving existing production code Understanding of automated testing (unit, integration, or component tests) Analytical and careful working style, especially when security or data integrity is involved Ability to work independently, research solutions, and take ownership of tasks Comfortable working with Git and collaborating asynchronously Nice-to-Haves Experience with TypeScript Familiarity with Microsoft ecosystems (Outlook, Exchange, integrations) Experience working in security-, privacy-, or compliance-sensitive environments Exposure to long-lived or legacy systems Familiarity with Nextcloud or open-source ecosystems This role is ideal if you want to become a strong medior engineer through responsibility, not just years on your CV. Benefits What You’ll Get €3,750 – €4,350 gross salary (40h/week, depending on experience) Hybrid setup, with an in-office day once a week, in an office right across in Eindhoven Central station, with strong autonomy and real ownership. NS Business card to cover your travel costs for on-site days 8% holiday pay 25 vacation days + public holidays Company laptop of your choice Home-office budget Work-from-home allowance Internet allowance A team that values quality, learning, and long-term thinking 🚀 Ready to Apply? If you’re a backend-focused engineer who wants to grow by owning real software, and you care about privacy, security, and doing things properly, we’d love to hear from you. Due to the hybrid nature of this role, applicants must be based in the Netherlands and have a valid work permit. Acquisition, mid-lance, or offshore constructions are not appreciated.