A leading digital bank in South Korea providing innovative financial services

Toss Bank is seeking an ML Backend Engineer to join their ML Service Team. The role focuses on developing backend servers and common service platforms for various AI products within Toss Bank.

The ML Service Team consists of Data Scientists who handle modeling from development to service implementation, and ML Engineers who are responsible for server development. Together, they create AI products, particularly working with product teams handling banking operations.

Key Responsibilities:
- Design and develop server architectures that enable stable serving of various AI products
- Develop individual services that can handle large-scale traffic reliably
- Create servers capable of serving computationally intensive AI models with stable response times and throughput
- Build environments to minimize failures while operating services with distributed tracing in MSA environments

The ideal candidate should have:
- Experience developing and operating servers using Python, Kotlin, Go, or similar languages
- Ability to design robust service architectures and implement stable code structures
- Experience with deploying and monitoring servers in Kubernetes environments
- Experience with high-traffic or high-SLA production services
- Interest in AI/ML field (prior ML experience not required)

You'll be working in a dynamic environment where AI/ML products are rapidly evolving, collaborating with product owners, designers, and developers. The role offers an opportunity to work on cutting-edge AI technology in the banking sector, handling everything from architecture design to implementation.

The position is full-time and includes a comprehensive interview process: document screening > live coding test > technical interview > cultural fit interview > reference check > compensation discussion > final offer.

ML Backend Engineer position at Toss Bank, developing and maintaining AI product infrastructure and services

ML Backend Engineer

A digital bank in South Korea providing innovative financial services as part of the Toss fintech ecosystem.

Join Toss Bank's Data Division as a Data Engineer specializing in Customer Data Products within the Data Platform team. The team is structured into three key parts: Platform, Product, and Governance. The Platform part manages Hadoop, Kafka, and CDC Platform infrastructure. The Product part focuses on building and operating unique data products using big data platforms. The Governance part establishes development standards and ensures compliance with banking regulations.

As a Data Engineer, you'll be instrumental in transforming complex banking systems into streamlined, customer-friendly solutions. You'll work with cutting-edge technologies including Hadoop, Spark, and Kotlin-based Spring Framework applications. The role involves developing data applications, managing large-scale distributed systems, and creating internal tools for data management.

The position offers unique opportunities to work with talented engineers and contribute to a rapidly growing fintech company. You'll collaborate across various departments, participating in everything from initial concept to final implementation of data solutions. The team values both specialists and all-rounders, welcoming those with deep expertise in specific areas as well as those looking to expand their skill set.

Toss Bank provides an environment where you can witness the direct impact of your work, as the data you handle is actively used throughout the company. The company's explosive growth means you'll face diverse, challenging data requirements, offering excellent opportunities for professional development. Working alongside exceptional colleagues in a fast-paced environment, you'll experience significant growth as a data engineer while contributing to innovative financial solutions.

Data Engineer position at Toss Bank focusing on customer data product development and management using big data technologies.

Data Engineer (Customer Data Product)

A leading Korean digital bank that's part of the Toss fintech ecosystem

Join Toss Bank's Data Division as a Data Engineer focusing on Governance within the Data Platform team. As part of a rapidly growing digital bank, you'll work on building and maintaining critical data infrastructure that powers one of Korea's most innovative financial institutions. The role combines technical expertise in data engineering with a focus on governance and regulatory compliance - a unique challenge in the regulated banking sector.

The Data Platform team consists of three key parts: Platform (handling Hadoop, Kafka, CDC Platform), Product (building bank-specific data products), and Governance (where this role sits). You'll be responsible for defining data product development standards and building platforms that meet banking regulatory requirements.

This is an opportunity to work with cutting-edge open source technologies while ensuring data reliability and compliance. You'll collaborate with various departments, understanding business objectives and engineering appropriate data solutions. The team emphasizes both technical excellence and practical business impact, offering exposure to both traditional banking requirements and modern data engineering practices.

Working at Toss Bank offers unique growth opportunities, especially for data engineers looking to make an impact in the fintech space. You'll be surrounded by talented engineers and work on challenging problems at scale. The bank's explosive growth means constantly evolving data requirements and opportunities to work on innovative solutions.

The position offers hands-on experience with modern data tools and technologies while building critical infrastructure for a rapidly growing digital bank. It's an ideal role for someone who wants to combine technical data engineering work with business-critical governance responsibilities in a dynamic fintech environment.

Data Engineer position at Toss Bank focusing on data governance, platform development, and regulatory compliance within the Data Division.

Data Engineer (Governance)

Toss Bank is a digital bank that's part of Toss, one of Korea's leading fintech companies.

Join Toss Bank as an Android Developer where you'll be part of both a squad and the Android chapter. The squad structure consists of 6-8 members from different roles working autonomously like a small startup. Every Thursday, the chapter members gather for Engineering Day to actively exchange knowledge, discuss technology, and share development expertise through code reviews.

As an Android Developer, you'll work on the Toss Bank Android app, which serves millions of users. You'll collaborate with cross-functional teams including Product Owners, Designers, and Server Developers. The role involves using Toss's proprietary design system (TDS) to rapidly create UIs and focus on core logic implementation. You'll be responsible for making technical decisions and setting priorities for Android development in your assigned services.

The tech stack includes Kotlin, Coroutines, RxJava, View System, Jetpack Compose, and follows the Model-View-Whatever architecture pattern. You'll be part of a team that releases new features weekly to over 10 million users, providing an opportunity to work at a fast pace with significant impact.

The company offers a unique blend of startup agility and large company resources. You'll have the autonomy to fully own product development while benefiting from the feedback and growth opportunities provided by the larger Toss engineering community. Regular chapter meetings and engineering days ensure continuous learning and knowledge sharing among team members.

This role is perfect for someone who wants to combine the excitement of building new features with the stability and scale of an established fintech leader. You'll be joining a team that values technical excellence, user experience, and continuous improvement.

Android Developer position at Toss Bank focusing on developing and maintaining the bank's mobile application, requiring 3+ years of experience and Kotlin expertise.

Android Developer

Toss Bank is a digital bank in South Korea, part of the Toss fintech ecosystem.

Join Toss Bank as an iOS Developer where you'll be part of two organizational structures - a squad/team and the iOS chapter. As part of the squad, you'll work with cross-functional teams to develop iOS services for Toss Bank. The iOS chapter provides a collaborative environment where developers support each other, share technical discussions, and grow together through weekly engineering days and technical seminars. You'll use cutting-edge technologies including Swift Concurrency, RxSwift, and SwiftUI, while working with Toss's proprietary design system (TDS). The role offers opportunities to make significant impact on a large-scale financial application used by millions of users. You'll be responsible for all iOS development decisions and work closely with product owners, designers, and server developers to create seamless user experiences. The position requires strong technical fundamentals, practical coding skills, and excellent collaboration abilities. Toss Bank values customer-centric development and encourages diverse technical experiments to improve user experience. The team uses modern iOS development practices and architectures including Multi-module App, Micro Feature Architecture, and various testing frameworks.

Senior iOS Developer position at Toss Bank focusing on developing financial services applications using Swift and modern iOS frameworks, requiring 3+ years of experience.

iOS Developer

A digital bank revolutionizing banking services in Korea with innovative technology and user experience

Toss Bank is seeking entry-level Server Developers to join our innovative digital banking team. As part of our product squads, you'll work alongside Product Owners, Designers, and Data Analysts in an autonomous startup-like environment. Our engineering teams consist of 3-5 developers per squad, focusing on various banking products including loans, deposits, and card services.

What makes us unique is our approach to banking - we're not bound by traditional banking conventions. Our developers come from promising IT companies and startups, questioning and redesigning banking fundamentals from scratch. We use cutting-edge technology, with our entire server infrastructure built in Kotlin, and we pride ourselves on having minimal legacy systems as a relatively new service.

You'll be part of developing high-performance, scalable banking systems that handle massive real-time traffic. Our tech stack includes Kotlin, Java, Spring Framework, and modern cloud infrastructure with Kubernetes. We're committed to creating the best banking service that everyone can use, and we offer a unique opportunity to make a significant impact in the financial technology sector.

The role involves working on both customer-facing services and internal management systems, with a focus on creating innovative solutions that challenge traditional banking norms. We value team players who are passionate about growth, enjoy sharing knowledge, and aren't afraid of change.

This is an excellent opportunity for new graduates to start their careers in a dynamic, technology-driven environment where they can contribute to transforming the banking industry through innovative software solutions.

Entry-level Server Developer position at Toss Bank, focusing on developing innovative banking systems using Kotlin/Java and modern cloud technologies.

[2025 H1 New Grad] Server Developer

A digital bank revolutionizing financial services in Korea through web technology

Join Toss Bank's Frontend Platform team where we're on a mission to 10X frontend developer productivity. We're building 'boosters' that help developers work faster through technical automation, tooling, testing, library development, and debugging environment improvements. Our team focuses on creating systems and tools that dramatically improve development efficiency - from automating manual tests to streamlining debugging processes.

We use modern technologies including React, TypeScript, Next.js for core development, along with state management tools like React-Query, Jotai, and Zustand. Our build infrastructure leverages Webpack, Rollup, ESBuild, and other cutting-edge tools. We've achieved significant improvements like reducing Docker image sizes by 90% through mono-repo optimization and implementing safety checks in CI pipelines to prevent deployment errors.

As a senior frontend platform engineer, you'll be responsible for identifying and implementing productivity improvements, fostering a culture of knowledge sharing, optimizing build/deploy pipelines, and creating developer-friendly tools and libraries. You'll work with a team of exceptional engineers in building the future of digital banking infrastructure.

The ideal candidate should have strong experience with frontend infrastructure, automation tools, and a passion for improving developer experiences. You'll have the opportunity to make significant impact on how dozens of frontend developers work and ultimately how millions of users experience digital banking.

Join us if you're passionate about creating scalable frontend infrastructure and want to work with one of Korea's most innovative fintech companies. At Toss Bank, you'll be at the forefront of financial technology while working with a team that values continuous improvement and engineering excellence.

Senior Frontend Platform Engineer position at Toss Bank focused on building developer tools and infrastructure to improve frontend development productivity

Frontend Developer (Platform)

Toss Bank is seeking a Finance(ALM) Developer to join their Data Division team. The role will be part of the Financial IT team within the Data Division, which includes various teams such as Risk Platform, Data Platform, ML Platform, and DataWarehouse that work closely together.

As an ALM Developer, you will be responsible for developing and operating the Asset Liability Management (ALM) system through close communication with the finance ALM business team. Your main responsibilities will include designing and implementing ALM data marts and financial simulations.

The ideal candidate should have experience managing risk ALM calculation systems in the financial sector, with strong programming skills in Python or Java. You'll be working with cutting-edge technology in a dynamic fintech environment, helping to build and shape the financial risk management systems from the ground up.

What makes this role unique is the opportunity to not just operate existing risk calculation systems, but to actually create and establish new system frameworks. You'll be working alongside talented colleagues in managing financial management calculation systems and building new frameworks.

The team operates within the Hadoop ecosystem and utilizes modern data processing technologies. This position offers the chance to work on complex financial systems while contributing to one of Korea's most innovative digital banks.

Benefits include competitive compensation, opportunities for professional growth, and the chance to work with cutting-edge financial technology. The position is full-time and based at Toss Bank's headquarters.

Senior Finance(ALM) Developer position at Toss Bank, focusing on developing and managing Asset Liability Management systems and financial risk calculations.

Toss Bank Engineering Jobs

A leading digital bank in South Korea providing innovative financial services