Revolutionizing Cross-Border Payments: Uncovering the Secret to Toss Bank’s Lightning-Fast FX Remittance Speeds
How Toss Bank Achieved 10x Faster Remittance Speed
The era of fast and convenient foreign currency remittances has arrived. With the help of banking apps and fintech services, users can now transfer foreign currency in just a few minutes. Toss Bank has recently launched a foreign currency remittance service that allows users to transfer foreign currency in less than a second, making it 10 times faster than Korean won remittances.
Overcoming Legacy System Limitations
Toss Bank engineer Se-kyung Jang introduced the development process of the currency exchange service at the Toss developer conference ”Toss Slash 24″. The team faced challenges in overcoming the limitations of legacy systems to provide faster services. Initially, Toss Bank’s core banking architecture was based on traditional technologies like Oracle and Kafka, which made it difficult to achieve faster processing speeds.
Adopting Microservices Architecture (MSA)
To overcome these limitations, Toss Bank adopted Microservices Architecture (MSA), which involves breaking down a large application into smaller units and developing and deploying each service independently. This approach allowed the team to use more efficient technologies like Redis and Kafka for transaction handling.

Engineer Jang explained that the team used Kotlin for core development and MySQL for DB storage. Additionally, they separated internal accounting processing asynchronously using Kafka. This approach allowed them to achieve faster processing speeds and reduce latency.
Achieving 10x Faster Remittance Speed
As a result of adopting MSA and using new technologies like Redis and Coroutines, Toss Bank was able to achieve foreign currency exchange services 10 times faster than Korean won remittance services. The processing speed of applications increased significantly, allowing for faster transaction processing.

Engineer Jang emphasized that the success of Toss Bank’s foreign currency exchange service is a result of incorporating modern technologies like Redis and Coroutines. The team’s efforts have paid off, allowing them to provide a faster and more convenient remittance service to their users.
A Stable Central Banking System
Toss Bank has also achieved a stable central banking system based on MySQL and MSA. The team has successfully handled 3,000 TPS traffic from Toss Home, generating 19.1 million MAUs. This demonstrates the stability and efficiency of their central banking database.
