About the job
The Toss Server Team builds and maintains the core systems that keep Toss services running smoothly. As a Server Developer focused on the Messaging Platform, the work centers on supporting reliable communication across a range of customer touchpoints and affiliated companies.
This role sits within the Platform Chapter, which develops shared libraries, gateways, and messaging systems. The team also maintains frameworks for logging, metrics, and other common features, enabling fast and stable service development. There is flexibility to move between chapters (Product, Platform, Productivity) after joining, matching evolving skills and interests.
What you will do
- Build and manage messaging systems for customer communications, including push notifications, alerts, and emails.
- Support experimental systems for A/B testing within Toss services.
- Implement unified messaging solutions across affiliated companies, such as banks and securities firms.
What we look for
- Experience designing, developing, and operating messaging systems.
- Background in building highly available and scalable systems.
- Ability to identify and resolve operational challenges in complex environments.
Technologies in use
- Kotlin, Java, Spring MVC, Spring Boot
- JPA/Hibernate, MySQL, MongoDB, Redis, Kafka
- ELK, Prometheus with Thanos, Grafana
Application tips
- Describe your experience with Toss's technology stack and the scale of traffic you have handled.
- Share examples of optimizing performance for high-traffic applications.
- If you have worked in mission-critical environments and taken responsibility for reliable services, highlight those experiences.
Hiring process
- Application submission
- First round technical interview (30 minutes)
- Second round technical interview
- Cultural fit interview
- Reference check
- Salary negotiation
- Final acceptance and onboarding

