Rebtel Tech Stack

International calling app for migrants and expats with pay-as-you-go and subscription plans

Telecommunications Stockholm, Stockholm 51–200 employees Privately Held

Rebtel serves dual-culture users—immigrants, expats, international students—with low-cost international calling to 190+ countries. The tech stack reveals a company modernizing aggressively: actively migrating from Java to Kotlin + Jetpack Compose on Android, replacing legacy systems across the board, and building new cross-functional product teams around payments and authentication. With 6 engineering hires posted in the last 30 days and senior-heavy seniority mix, Rebtel is scaling to handle millions of users in a high-volume transactional environment while paying down technical debt.

Tech Stack 33 technologies

Core Stack.NET GitHub Jira Confluence ASP.NET SQL Server MongoDB Azure DevOps Kubernetes GraphQL Next.js TypeScript Cypress JavaScript React Angular Vue Cursor AWS iOS Android NET Core .NET Framework Git REST API React Testing Library Claude Codex GCP Azure

AdoptingKotlin Jetpack Compose

ReplacingJava

What Rebtel Is Building

◆Challenges

Reducing tech debt
Scaling services for millions of users
Ensuring payment reliability
Reducing redundant work
Balancing pricing and margins
High-volume transactional environment
Retain top engineering talent
Migrating legacy android code to modern stack
Replacing legacy system
Modernizing legacy systems

▲Active Projects

Payments roadmap
Authentication roadmap
Shared ux patterns
Mobile top-up product
New cross functional product delivery team
Calling and top up experiences
Migration from java to kotlin + compose stack
Modernizing android features
Replacing legacy system
Ai vision and experimentation

Hiring Activity

Accelerating9 roles · 6 in 30d

Department

Engineering

Product

Seniority

Senior

Manager

C-Level

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About Rebtel

Rebtel is a direct-to-consumer telecom company built around the communication needs of global migrant communities over the past two decades. The product offers international calling to mobiles and landlines with transparent pricing, flexible payment (pay-as-you-go and country-specific unlimited plans), multilingual support, and local currency options. Revenue scales through credits and subscriptions; the go-to-market relies on performance marketing and community partnerships. The company operates at scale—millions of users, high transaction volume—across iOS and Android, backed by a .NET-based backend on Azure and AWS infrastructure.

HeadquartersStockholm, Stockholm

Company Size51–200 employees

Hiring MarketsSweden

Frequently Asked Questions

What tech stack does Rebtel use?

Backend: .NET Core, ASP.NET, SQL Server, MongoDB on Azure and AWS. Mobile: iOS (native), Android (Java → Kotlin + Jetpack Compose migration underway). Frontend: React, Next.js, TypeScript. Infrastructure: Kubernetes, GraphQL, REST APIs. DevOps: GitHub, Azure DevOps.

What is Rebtel working on?

Payments and authentication roadmaps, mobile top-up product, new cross-functional product delivery teams, modernizing Android from legacy Java to Kotlin + Jetpack Compose, replacing legacy systems, and AI vision and experimentation projects.