Toss Tech Stack

Korean SuperApp ecosystem spanning payments, shopping, loans, and financial services

Financial Services Seoul , Seoul 1,001–5,000 employees Privately Held

Toss operates a 30-million-user financial SuperApp built on a polyglot backend (Java, Kotlin, Spring, Kafka) deployed across Kubernetes with heavy observability tooling (Elasticsearch, Grafana, InfluxDB). The tech stack reveals dual scaling challenges: real-time traffic handling and data consistency issues drive infrastructure investment (Istio, Kafka, Iceberg adoption), while frontend friction is triggering active projects around dev environment overhaul and an independent platform team focused on tooling. Hiring is accelerating with engineering and product leading the mix—typical of a mature consumer app shifting from user acquisition toward operational and feature complexity.

Tech Stack 138 technologies

Core StackKubernetes Istio Hibernate Jenkins Docker Kafka Elasticsearch InfluxDB Grafana AWS React Vue Angular Next.js Webpack GitHub Actions CircleCI Java Kotlin Spring Framework Gradle Git Memcached React Query Recoil Yarn pnpm esbuild SWC Babel+102 more

AdoptingKubernetes Iceberg SNMP Syslog TACACS+ IPsec SSL VPN

What Toss Is Building

◆Challenges

Handling large real-time traffic
Inefficiencies
Data consistency
High availability system design
Employee focus improvement
Improving frontend dev environment
Scaling frontend resources
Designing highly available scalable systems
Improving recommendation performance
Increasing user growth

▲Active Projects

New menu development
Toss shopping
Enterprise and business unit financial strategy development and execution
Loan comparison service
Frontend development environment improvement
Search and ranking algorithm development
Gpu cluster operation and optimization
Nlp for search experience
Marketplace for financial services
Payment service

Hiring Activity

Accelerating140 roles · 75 in 30d

Department

Engineering

Product

Data

Legal

Sales

Finance

Design

Seniority

Mid

Senior

Manager

Junior

Lead

Staff

Director

Notable leadership hires: Risk Management Lead

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About Toss

Toss is South Korea's leading SuperApp, launched in 2015 as a money transfer service and now operating a platform of over 100 integrated services. The company serves 30 million users across financial management, shopping, loan comparison, and marketplace services. Operations are centered in Seoul with a workforce of 1,001–5,000 employees. The product architecture spans payment rails, lending, e-commerce, and search with real-time requirements; the engineering org is actively addressing high-availability system design, data consistency, and recommendation performance as core operational priorities.

HeadquartersSeoul , Seoul

Company Size1,001–5,000 employees

Hiring MarketsSouth Korea

Frequently Asked Questions

What tech stack does Toss use?

Toss runs Java and Kotlin on Spring Framework, deployed via Kubernetes and Istio, with Kafka for event streaming, Elasticsearch for search, and Grafana/InfluxDB for observability. Frontend uses React, Vue, and Next.js with Webpack, esbuild, and SWC.