.NET Engineer

Senior .NET Engineer | Microsoft Teams & Voice Communications

We're looking for an experienced Senior .NET Engineer to help us build and evolve a communication platform deeply integrated with Microsoft Teams.
You'll work on features that power real-time communication, including calls, meetings, recordings, notifications, and communication data.
This is an opportunity to work with complex integrations, solve challenging engineering problems, and contribute to a product where your technical decisions make a real difference.

What you'll do
Design, develop, and optimize backend services using C#, .NET, and ASP.NET Core.
Build and maintain integrations with Microsoft Teams, Microsoft Graph API, and Teams Communications APIs.
Develop features for calls, meetings, recordings, and communication data.
Create and support Microsoft Teams bots on Azure, including real-time notifications and activity processing.
Implement and enhance Teams activity feed notifications.
Develop and maintain frontend features using React.
Build and integrate REST APIs and external services.
Configure and manage Azure-hosted services, bot authentication, and permissions using Microsoft Entra ID.
Investigate complex production issues and ensure system reliability.
Improve platform performance, scalability, and overall architecture.
Take ownership of technical solutions and collaborate on product improvements.

What we're looking for
5+ years of commercial experience with C# / .NET.
Strong expertise in ASP.NET Core and backend development.
Hands-on experience with React.
Proven commercial experience with Microsoft Teams integrations.
Strong practical knowledge of Microsoft Graph API.
Experience with Microsoft Graph Communications API and Teams Calls & Meetings APIs.
Experience developing solutions involving calls, meetings, and recordings, including compliance or call-recording functionality.
Understanding of VoIP, telephony systems, and voice communication platforms.
Familiarity with real-time audio/media processing, WebRTC, SIP, and RTP.
Experience with SignalR / WebSockets.
Practical experience with Azure, including hosting and managing bots and backend services.
Experience with REST APIs, SQL, and relational databases.
Strong understanding of backend architecture, integrations, and production troubleshooting.
Ability to independently drive technical tasks and make well-reasoned engineering decisions.
English — B2+.

What we offer:
Flexible work format — remote or hybrid, with an office in Lviv
18 paid vacation days + 5 sick days
10 additional days off per year
Regular performance reviews and feedback
Professional growth and development opportunities
Mentorship and support from experienced colleagues
Accounting support
Free lunches at the office
Team events and company gifts
Anniversary gifts