Tandem - Language Exchange Tech Stack

Global language exchange platform connecting 35M+ learners across 300+ languages

E-Learning Providers Berlin, Berlin 11–50 employees Founded 2015 Privately Held

Tandem operates a peer-to-peer language learning marketplace with 35 million members. The engineering footprint—PHP, Go, Swift, Kotlin Multiplatform across iOS and backend—reflects a multi-platform mobile-first product. Active projects center on microservices migration, distributed system scaling, and Kotlin Multiplatform adoption, paired with reliability and observability work, indicating the infrastructure challenges that come with a platform of this scale. Hiring velocity is accelerating across engineering, product, and marketing, with leadership gaps being filled.

Tech Stack 11 technologies

Core StackPHP Go AWS Swift SwiftUI Kotlin Azure Objective-C UIKit CI/CD Kotlin Multiplatform

What Tandem - Language Exchange Is Building

◆Challenges

Migrating monolithic architecture to microservices
Modernizing legacy ios codebase
Scaling architecture
Maintaining performance and reliability
Scaling product culture
Modernizing product tech stack
Improving product velocity
Code and platform modernization
Reliability, scalability, observability

▲Active Projects

Technical refactoring and modernization initiatives
Transitioning monolith to microservices
Building distributed high-traffic systems
Managing cloud deployments
Tiktok and instagram video content creation
Youtube seo content production
Realtime chat and media services
Kotlin multiplatform
Ios accessibility features
Ai tools adoption

Hiring Activity

Accelerating5 roles · 3 in 30d

Department

Engineering

Product

Marketing

Seniority

Senior

Junior

Lead

Mid

Notable leadership hires: Head of Product

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About Tandem - Language Exchange

Tandem is a Berlin-based language learning community founded in 2015 that connects language learners globally for peer-to-peer conversation practice. The platform supports learning in over 300 languages, including sign languages, indigenous languages, and constructed languages. The core product is a mobile marketplace application (iOS and Android) that pairs learners for real-time chat and media exchange. The company operates a freemium model with a base of 35 million registered members. Technical operations run on AWS and Azure, with a 11–50 person team based in Germany.

HeadquartersBerlin, Berlin

Company Size11–50 employees

Founded2015

Hiring MarketsGermany

Frequently Asked Questions

What tech stack does Tandem use?

Backend: PHP and Go. Mobile: Swift, Objective-C, UIKit, and SwiftUI on iOS; Kotlin and Kotlin Multiplatform for cross-platform development. Infrastructure: AWS and Azure, with CI/CD pipelines.

What is Tandem working on?

Primary focus: migrating from monolithic to microservices architecture, scaling distributed systems for high traffic, and modernizing legacy iOS code. Secondary: Kotlin Multiplatform development, iOS accessibility, real-time chat/media infrastructure, and AI tool adoption.