Full Stack .NET Engineer
Summary
Builds and maintains backend services in C#/.NET for a voice communication and call analytics platform, working on end-to-end call flows, recording, REST APIs, and real-time features with SignalR, WebSockets, WebRTC, and Twilio, plus integrations with telephony/CRM systems and some React/TypeScript frontend work.
Full Stack .NET Engineer (Voice / Telephony Platform)
We are looking for a .NET Engineer to join a product development team working on a voice communication and conversation analytics platform.
The product supports real-time voice communications, call recording and processing, and integrations with telephony providers, contact center solutions, and CRM platforms.
The role is primarily focused on backend development with C#/.NET. We are looking for an engineer with solid backend expertise who is comfortable working with APIs, integrations, databases, and real-time systems.
Experience in telephony, VoIP, WebRTC, SIP, UCaaS/CCaaS, or contact center solutions would be a strong advantage.
Tech Stack
C# / .NET 6+ · ASP.NET Core · MS SQL · REST APIs · SignalR · WebSockets · Twilio · WebRTC · Azure · React.js / TypeScript
Responsibilities
Develop and maintain backend services using C# / .NET
Build new functionality for voice communication and call recording
Work with end-to-end call flows, including call initiation, routing, recording, storage, and retrieval
Design, develop, and maintain REST APIs
Build integrations with telephony providers, communication platforms, contact center systems, and CRMs
Develop real-time functionality using SignalR, WebSockets, WebRTC, and Twilio
Work with relational databases and optimize data access
Troubleshoot issues related to call flows, third-party integrations, and real-time communications
Improve application performance, reliability, and scalability
Participate in technical discussions, estimations, and code reviews
Collaborate with Product, QA, and Engineering teams throughout the development lifecycle
Requirements
3+ years of commercial software development experience
Strong commercial experience with C# / .NET
Good knowledge of ASP.NET Core
Solid understanding of backend development and client-server architecture
Experience developing and integrating REST APIs
Experience with relational databases and SQL
Good understanding of asynchronous programming and concurrency
Experience working with integration-heavy and/or real-time systems
Understanding of software architecture principles, design patterns, and clean code practices
Experience with Git and modern development workflows
English — B2+
Key Experience
Experience with telephony, VoIP, UCaaS/CCaaS, contact center, or voice communication products
Knowledge of SIP and RTP
Experience with WebRTC
Experience with call recording, audio/media processing, or real-time media streaming
Experience with Twilio or similar communication APIs
Experience with SignalR / WebSockets
Integration experience with RingCentral, Microsoft Teams, Zoom, Cisco Webex, Avaya, 8x8, Genesys, Five9, or similar platforms
Experience troubleshooting network, connectivity, or voice communication issues
Experience with Azure
Experience with microservices or distributed systems
Docker and CI/CD experience
React.js / TypeScript knowledge
Experience with transcription, speech-to-text, conversation analytics, or AI/NLP solutions
What’s In It for You?
Career Growth – Opportunities to develop and advance.
Performance Reviews – Regular feedback and support.
Work Anniversaries – Special gifts to celebrate milestones.
Flexible Work – Hybrid or remote (Lviv office available).
Mentorship – Guidance from experienced professionals.
Accounting Support – We handle the paperwork.
Paid Time Off – 18 vacation days + 5 sick days per year.
Extra Leave – 10 additional days off annually.
Free Office Lunches – Enjoy meals on us.
Team Events – Gatherings, gifts, and a welcoming atmosphere.