Case Study: Toss Lab achieves 99.9% uptime and scalable global SaaS with Amazon Web Services

Toss Lab - Customer Case Study

Toss Lab develops JANDI, an AWS-based SaaS business messenger optimized for Asia and used by over 80,000 users across Korea, Taiwan, Vietnam and China. With limited budget and resources, the team needed a secure, highly available platform that supported concurrent file/message sharing and ensured users could access historical chat content while handling unpredictable traffic spikes and global access requirements.

Toss Lab built JANDI on AWS—using Application Load Balancers, Auto Scaling, EC2, S3 + CloudFront, RDS, ElastiCache for Redis, Lambda, SQS and MongoDB replica sets—to deliver scalable, low-latency service. The result was faster re-architecture, reduced upfront costs, robust monitoring via CloudWatch, reliable handling of traffic surges and a 99.9% SLA, while AWS partnership and Marketplace plans support further global expansion.

Toss Lab

Sangrok Jeon

Director of Development