TelGuarder App

One of the projects we’ve been actively working on for the last couple of years is telGuarder, a proven cloud-based call blocker solution available in 44 countries across the globe.

Based both on advanced algorithms and crowdsourcing approach, telGuarder allows users to search through 8 million telephone numbers with automated and user-generated reports in seconds. In addition, the mobile app blocks spam, telemarketing, automated and suspicious calls.

Except for the web version of the product, telGuarder is also available as a mobile app for Android systems, and at this point has more than one million downloads from Google Play.

telGuarder AS partners with Caddiesoft on the full-stack web and back-end app development.

telguarder facts


Available for 44

4.1 out of 5 stars
(Google Play)

Collaboration model

Dedicated development team

Project duration and status

4 years, ongoing


telGuarder resulted from the attempt to expand the reach of a call detection and blocking app 180 beyond Scandinavian countries.

After the project had proven to be successful in Norway, Denmark, Sweden and UK, the Caddiesoft team started working on the development of telGuarder.

The product was first released for Brazil and Mexico, and then expanded its servicing area to 42 more countries around the world.

The presence in new markets and on different continents introduced new challenges for the development team, such as backend response latency and performance issues.


Challenges and solutions

1. Backend response latency

After the release of telGuarder, the back-end systems located in Scandinavia would not respond promptly to requests sent by localized front-end components due to extremely long distances between them.


  • The use of Microsoft Azure cloud services (their servers located in Americas, Europe, India and Australia) to ensure geographical proximity between our backend databases and the end users.

2. Traffic management between nodes

The process of data distribution between servers led to significant traffic and maintenance expenses. The development team addressed this issue with the following solutions:


  • The development of a hybrid system, where both local servers in Norway and Microsoft Azure storages and services operate simultaneously and interdependently.

  • The incorporation of a delta-update-based principle into the data exchange process, where only the modified piece of information is transferred between components, instead of the whole data set. This approach allowed us to significantly minimize traffic between different parts of the distributed backend system, and consequently improve performance and decrease maintenance costs.

telguarder android

3. Data processing and management

As the service became more popular and sophisticated, and the amount of data to be processed significantly increased, there was a need for proven and powerful solutions to ensure streamlined and stable operation.


  • Expanded use of NoSQL solutions (MongoDB and Cosmos DB tools) in addition to SQL capacities. That allowed our team to significantly decrease data latency and improve overall performance. 

Tech stack

Language | Framework​ | Monitoring and performance management


.NET Core



Databases | Servers



Microsoft Azure (Cosmos DB, Web Apps, Traffic Manager, Front Door)


Our team is responsible for the platform’s design and development, as well as the back-end development of the app services and UI.UX design.

Utvikler i Caddiesoft
Artyom Skosar

Team lead
Senior full-stack .NET developer

.net utvikler i Caddiesoft
Valeriy Baditsa

Senior full-stack .NET developer

.NET-utvikler i Caddiesoft
Ivan Efimov

Senior full-stack .NET developer


"Working on this project was a great opportunity for me to expand my knowledge of cloud technologies, to see the way they work and possibilities they provide. With telGuarder, Microsoft Azure cloud technology turned out to be the optimal solution, and it was really exciting to see things work".

Artyom Skosar

Team lead

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