Staff Software Backend Engineer - Messaging and Caching Platform

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

Join Our Team! At Toss, we are pioneering the offline payment industry and are passionately driving change within the payment ecosystem. The Platform Server Developer will be a key member of the platform team, focusing on developing server platforms that support all services, monitoring issues as part of SRE, enhancing deployment pipelines as DevOps, and collaborating closely with developers across different silos. You will work within a dedicated server platform team that ensures rapid recovery from service disruptions and maintains stable operations. Your Responsibilities: Develop common functionalities (such as Metric, Logging, Distributed Lock, Messaging) required by Server Developers at Toss using Java/Kotlin and Spring Framework. Create and manage platform services relevant to common interests (API Gateway, Monitoring & Alert System) used in Toss. Monitor server infrastructure at Toss, quickly detect issues, and work towards rapid recovery. Continuously improve the architecture from a holistic system perspective. We Are Looking For: Individuals with experience in providing server functionalities. Familiarity with technologies like Redis, Kafka, and ELK stack is a plus. Experience in designing and operating high-availability scalable systems. Experience in handling systems that manage large-scale real-time traffic. Proficiency in monitoring, troubleshooting, and performance tuning across various layers such as Spring Framework, JVM, OS, and Network. People who embrace change and want to continuously enhance services and infrastructure using appropriate technologies. Resume Recommendations: Please detail your experience related to platform-related tasks (common services, common library implementation and operation) and the reasons behind them. If you have designed and operated high-availability scalable systems, please explain your rationale and relevant experiences. For those with experience in designing and operating systems that manage large-scale real-time traffic, please include specific troubleshooting or performance improvement processes you encountered while operating services. Technologies Used at Toss: Kotlin, Java, Gradle Netty, Spring MVC, Spring Webflux, Spring Boot, Spring Cloud Gateway, and more.

Join Our Team! As a Server Developer (Platform) at Toss Bank, you will be an integral part of our Platform Team, ensuring the seamless operation of our banking services. We are dedicated to rapid recovery from unexpected service disruptions, preparing thoroughly to maintain stable and reliable operations. Our team consists of talented professionals from promising IT companies, all committed to ensuring the stability of our banking systems. We aim to enhance user experience by enabling our users to enjoy safe, fast, and reliable banking services through automated analysis and runtime enhancements. Your Responsibilities: You will develop and operate platform services used by Toss Bank (including high-volume message delivery, API gateways, APM, monitoring & alert systems, ELK, HAProxy, etc.). Provide common functionalities (Metric, Logging, Message Queue, Distributed Lock, Memory Cache, etc.) as platform libraries for our services. Implement redundancy measures to ensure stable service operations. Respond to various failures, analyze incidents, and work to prevent future occurrences. Collaborate with the infrastructure team during large data center operations to ensure service continuity. Who We’re Looking For: Experience in designing and operating highly available, scalable systems is essential. Experience in developing systems that handle large-scale real-time traffic is required. Proficiency in development using the Spring Framework is necessary. A history of continuous efforts in performance optimization and operational automation. Quick thinking and problem-solving skills are a must. A willingness to embrace change and adapt quickly to new technologies for ongoing growth. Ability to foster growth among fellow developers through collaboration. Enjoyment of mission-critical service environments with a strong sense of responsibility. Please include the following in your resume: A minimum of one specific project you participated in, detailing your contributions and the process of overcoming challenging tasks. Share various problems encountered while operating systems and detail your personal attempts and results in resolving those issues. If you have similar experiences in developing systems that handle large-scale real-time traffic, please provide detailed examples. Share your growth aspirations as a developer and the efforts you are making toward that growth.

About the Team You'll JoinThe Server Developer for Toss Bank's Savings Platform is a key member of the Savings Platform Team, collaborating closely with various squads (such as Savings, Groups, Forex, and Remittances) to deliver exceptional financial products.Our Savings Platform is transitioning to a microservices architecture (MSA), focusing on core functionalities like account creation, remittances, account closures, interest calculations, and currency exchanges.Previously constructed under a monolithic structure based on MDD, we are currently reforming our systems using Kotlin and Spring, with successful implementations like 'Instant Interest' and 'Lifetime Free Currency Exchange' already operational on the MSA.Your Future ResponsibilitiesYou will manage the design, development, and operation of our core deposit system, which handles everything from account openings to remittances, interest calculations, and closures.Redesigning the savings platform into an MSA architecture will enable us to overcome previous limitations and facilitate the rapid introduction of new products and features.In addition to savings, you will collaborate across domains including Forex, cards, and external integrations, ensuring a seamless customer experience while maintaining data consistency, transaction stability, and an automated testing environment.Who We're Looking ForWe are excited to meet individuals eager to step outside their comfort zones and challenge the norms by creating a completely new banking experience.If you have a passion for solving fundamental issues such as data flow, consistency across complex domains, and transaction design, you will thrive in this role.Experience in domain-centric data modeling, designing testable structures, and quality management from an operational perspective is highly valued.Beyond mere implementation, having a background in understanding and improving problem structures, along with experience in accountable communication with related departments, will be significant assets.Experience in designing and operating services using RDB systems such as Oracle or MySQL is also welcome.Resume RequirementsPlease include at least one concrete example of a project you participated in, showcasing your contributions and the challenges you overcame.As part of service development, problem-solving skills are crucial. Clearly detail a problem you faced, the attempts you made to solve it, and the results achieved.If you have automated repetitive issues or solved problems in innovative ways, please include those examples.Share experiences where you addressed complex domain issues or enhanced operational stability within technical constraints (legacy systems, shared components, etc.).Additionally, if you have made genuine improvements within restricted environments due to organizational culture or external regulations, please outline those experiences.Joining Toss BankApplication Submission > Interview Process > Offer

About the Team You'll Join The Server Developer (Market Platform) will be part of the Market Team, dedicated to developing the ‘Toss Securities Market Platform’. The Market Team handles various essential tasks for securities services, including the provision of domestic and international stock prices. The team's objective is to deliver an optimized, ultra-efficient system. Our engineers are responsible for market data, actively collaborating to determine necessary features and shaping the development direction. Your Responsibilities Develop a broad range of applications from customer-facing APIs/WebSockets to external organization communications. Gain experience with real-time high-volume traffic and low-latency event processing, often tackling complex challenges. Contribute to architectural improvements, focusing on deployability, operational ease, stability, and performance enhancement. Who We Want to Work With We are looking for individuals who excel at solving complex problems. Those who embrace change, adopt new technologies, and demonstrate a strong sense of responsibility will thrive here. Proficiency in Go, Kotlin, and Spring Framework is a plus. Experience in developing mission-critical systems is highly desirable. Background in real-time data processing and network programming would be beneficial. Resume Recommendations Highlight impactful projects and contributions. Detail the problems you have solved, the thought process behind your solutions, and the outcomes achieved. Technologies Used at Toss Securities Go, Kotlin/Spring Boot, Netty Redis, MySQL, Kafka, NATS The Journey to Joining Toss Securities Application submission > Live coding interview > Technical interview > Cultural fit interview > Reference check > Offer negotiation > Final acceptance and onboarding Additional Information Any falsified information in your resume or documented disciplinary actions during your employment history may lead to cancellation of the hiring process. Individuals identified as ineligible for hire under Toss Securities regulations may have their application revoked. We prioritize candidates with disabilities and veterans in accordance with relevant laws.

Join Our Dynamic Team!The Platform Server Developer will be an integral part of our server platform team.At Toss, we operate in agile, small groups comprised of planners, designers, and developers, working collaboratively to deliver exceptional services. The server platform team focuses on creating common functionalities and frameworks that support these agile teams.This year, our goal is to enable faster and easier launches of our securities services while ensuring stable operations. We are poised to expand our offerings significantly.Unlike other teams, our server platform team does not have dedicated planners. Our engineers take the lead, identifying necessary features, gathering input, and guiding development.Your Responsibilities Will Include:Consolidating and standardizing common challenges faced by developers and addressing these by adding new features.Utilizing Java/Kotlin and the Spring Framework as our primary server development environment, you will select and implement efficient practices from a variety of libraries and methodologies.Engaging in performance improvements using profiling tools, thoughtfully considering how to enhance performance, and translating those insights into actionable items.Evaluating and enhancing the overall architecture for deployability, operational efficiency, stability, and performance improvements.We Are Looking For Candidates Who:Are proficient in Java/Kotlin and the Spring Framework.Have experience with Redis, Kafka, or the ELK stack.Possess troubleshooting experience across layers such as Spring Framework, Tomcat, JVM, OS, networking, and infrastructure, including performance tuning.Have a background in real-time data processing and network programming.Are adaptable and eager to embrace new technologies to continually advance our services and infrastructure.Resume Tips:We prefer insights into your learning experiences rather than just a list of tasks. Particularly, we are interested in any service disruptions you faced, how you resolved them, and what you learned.Share any experience you have with platform work (common services, libraries) and whether you have independently identified and developed common functionalities.Detail your experiences with monitoring and alerts in server development and any challenges you encountered.Technologies We Use:Java, Kotlin, Golang, Spring Framework, NettyMySQL, Oracle, Redis, MongoDB, Kafka, Elasticsearch, GrafanaYour Journey with Toss Securities:Job interview > Cultural fit interview > References...

Join our dynamic Server Platform team at Toss, where we play a critical role in ensuring the stability and reliability of all Toss services. Our team is dedicated to building a solid foundation for our services to operate smoothly.As part of the Server Platform team, you will collaborate closely with Site Reliability Engineers focused on preventing outages, DevOps Engineers enhancing deployment pipelines, and Server Developers working on various products.We prepare meticulously to ensure rapid recovery from service disruptions, providing robust support for backend operations that allow service developers to respond effectively to users.To enhance the security and reliability of financial transactions, we implement features such as degraded functionality at the Gateway level, automate analysis, and strengthen runtime analysis capabilities.Our initiatives also focus on improving performance through various profiling methods and hardware acceleration, alongside architectural enhancements.To boost developer productivity, we offer common libraries for distributed locking, logging, and metrics.

We are seeking a talented Server Developer with a focus on Blockchain technology to join our dynamic team. In this role, you will be responsible for designing, developing, and maintaining server-side applications that leverage blockchain technology. Your expertise will contribute to innovative solutions that enhance our platform's capabilities and user experience.

Join our innovative team at Toss as a Server Developer (여신) where you will play a crucial role in designing and optimizing our server-side systems. We are looking for passionate developers who thrive in a fast-paced environment and are eager to tackle complex challenges. Your expertise will directly contribute to enhancing our platform's performance and scalability.

About the Domain You'll Join Toss is composed of several domains that operate as independent businesses, including Growth, Foundation, Commerce, Pay, Financial Marketplace, and Ads & Benefit. The Growth domain is designed to drive an increase in Toss app users and generate higher revenue per user. To propel Toss's growth, it is essential to not only attract new users but also encourage existing users to utilize more services within the app. You will be responsible for analyzing and improving existing services while also creating new services that contribute to user growth. Your Responsibilities Design and develop the product server utilized by numerous Toss customers. Establish valid hypotheses and validate them through experiments, utilizing data insights to progressively enhance product-market fit. Leverage trendy technologies to ensure stable service operation, while listening to user feedback to quickly and flexibly resolve issues. What You Should Note This position is aimed at individuals interested in creating new services that drive growth. While it shares similarities with the existing Server Developer (Product) role, it will specifically place you in the Growth domain. If you wish to have flexibility in your placement based on your strengths, consider applying for the [Server Developer (Product)](https://toss.im/career/job-detail?job_id=4071141003) position. Please note that Toss is not hiring individuals eligible for military service exceptions (industrial personnel, research personnel) at this time. Who We Are Looking For Individuals with experience in designing and operating high-availability scalable systems. Developers who have experience in creating systems that handle large-scale real-time traffic. Those who have encountered and resolved issues during system outages. Individuals who are passionate about their services and approach their work with a sense of ownership. Collaborative team players who are eager to share insights and ideas gained from service development, constantly seeking technical challenges. Technologies We Use at Toss Kotlin, Spring MySQL, MongoDB, Hadoop, Redis, Kafka, Elasticsearch The Journey to Join Toss Application submission > Functional interview > Cultural fit interview > Reference check > Offer negotiation > Final acceptance and onboarding A Note for Future Colleagues "Let's achieve explosive growth together in the Growth Domain!" The Growth domain is the ideal environment for those who love products and believe in the importance of analysis. You'll have plenty of opportunities to advance your career alongside outstanding makers. Creating value through deep analysis leads to daily dynamism and excitement in the Growth domain, with metrics like MAU and ARPU providing immediate feedback on your impact.

Join Our TeamThe Server Developer (Product) is an integral part of Toss's Maker Organization, Silo. Within each Silo, a diverse team of 6-8 professionals, including product owners, designers, developers, and data analysts, collaborates with autonomy, akin to a small startup.As our user base expands, our dedicated team of server developers ensures stable operations, supporting various services across Toss, distinct from the rapid experiments conducted within the Silo.What You'll Be DoingDesigning and developing the Product server, utilized daily by countless Toss customers.Offering over 50 diverse services since the launch of our easy remittance service in 2015, including financial status inquiries, pedometers, and luck quizzes.Implementing cutting-edge technologies to ensure service stability while promptly addressing user feedback and issues.Who We're Looking ForIndividuals with experience in designing and operating high-availability, scalable systems.Professionals with a background in developing systems that manage large-scale real-time traffic.People who have faced and resolved system outages effectively.Passionate individuals who treat the service as their own, embodying a sense of ownership.Collaborators eager to share insights and ideas gained from service development, constantly seeking technical challenges.Services You Will HandleLoan: Create services that allow users to easily compare various loans and manage them efficiently. We aim to be the go-to choice for credit loans, mortgage loans, refinancing loans, and card loans.Marketplace: Develop essential services, such as credit card benefit comparisons, investments, and auto insurance, for financial users.Payment: Work on Toss's simple payment service, TossPay, handling everything from online and offline payments to new payment method development and user acquisition promotions.Commerce: Enhance Toss's payment capabilities through commerce initiatives, launching group-buying and seller admin services to create value for both users and sellers.Benefits: Lead the creation of innovative services in the benefits tab, including pedometers, live shopping, lucky lotteries, and point rewards for friends.Ads: Expand Toss's advertising business, developing stable-serving products that handle large traffic volumes while integrating ad network developments.Home: Create services related to the home screen, the first touchpoint for all Toss users, analyzing assets and expenditures while connecting users to other relevant Toss services.

All applicants will have the opportunity to take a coding test!Experience unique to Toss Payments."Discover new possibilities alongside colleagues who help reduce trial and error."Create products with a lifespan of over 20 years that impact various merchants utilizing Toss Payments.Engage in complex tasks that involve understanding the history of previous technologies to identify improvement strategies.All engineers work towards a common goal, collaborating across teams on specific problems and organically removing blockers during the solution process.Embrace challenges and try anything to overcome your limits and discover new potentials.About Toss Payments:- Toss Payments aims to provide all necessary solutions for businesses, from technology to operations, understanding the challenges and inefficiencies they face. We create products that offer consumers a simple and convenient service experience while ensuring merchants can focus solely on their business.- We operate under the principles of autonomy and responsibility, fostering a strong culture of mutual trust as we pursue our core goal of 'innovating the electronic payment market.' We are looking for colleagues who will help shape the future of the payment industry!What you'll be working on:- Develop scalable and flexible systems to easily implement the continuously increasing payment requests and diverse requirements.- Create systems capable of handling traffic surges, such as those during flash sales, without crashing.- Build settlement systems that can quickly and accurately compute numerous transactions with hundreds of requirements.- Develop new APIs to address business difficulties in a microservices architecture that allows for seamless and uninterrupted deployments.- Establish an ecosystem to support OpenAPI, connecting Toss Payments with client systems.Who can apply:- Individuals with less than 3 years of practical development experience.- Those with no restrictions on overseas travel.- Candidates available to join by June 2024.Technologies used at Toss Payments:- Java, Kotlin, Gradle- Spring MVC, Spring Webflux, Spring Batch, JPA, Spring Cloud Gateway, Spring Cloud Config, Netty- MySQL, Redis, ElasticSearch, Kafka, OracleThe joining process at Toss Payments:- Application submission > Coding test > Job interview > Cultural fit interview > Reference check > Negotiation of terms > Final acceptance and onboarding.- Application submission: April 15 (Monday) to April 24 (Wednesday) by 23:59.- Coding test: April 27 (Saturday) at 14:00 (90 minutes total).- The test will consist of 60 minutes of algorithm questions and 30 minutes of descriptive questions.- Subsequent hiring process: Only those who pass the coding test will be notified of individual schedules.- Onboarding: To take place in June.Coding test details:- The coding test will be sent to the registered email on April 27 (Saturday) at 2 PM.- Time limit: 90 minutes.- Submission deadline for the coding test: April 27 (Saturday) at 3:30 PM.- All applicants will have the opportunity to take the coding test.Frequently Asked Questions:Q. Can I apply if I have a past rejection?- There are no restrictions on applying for the Toss Payments Server Developer position for those with less than 3 years of experience. Feel free to apply even if you have been previously rejected.Q. Can industrial function personnel or specialized research personnel apply?- Currently, Toss Payments does not permit the hiring of personnel under military service exceptions, thus they cannot apply.Q. Can foreigners or those living abroad apply?- If you have received a work visa or have no issues obtaining one, you are eligible to apply.

Join our dynamic Commerce domain where innovation thrives! Toss operates multiple domains, each focusing on self-sufficient businesses, including Commerce, Pay, Financial Marketplace, Ads & Benefit, Foundation, and Growth. Our Commerce domain is the fastest-growing segment within Toss. Having launched Toss Shopping and Toss Shopping Partners, along with shopping ad services, we are continuously creating new value for both users and sellers. Inside the Commerce domain, teams like Shopping Silo, Shopping Platform, Shopping Ad Silo, and Commerce Business work collaboratively like a startup. As we embark on this new journey in 2024, we aim to expand the functionalities of our Commerce platform and strengthen its foundational capabilities. Your responsibilities will include: Designing and developing the Product server used by countless Toss Commerce customers. Creating diverse services such as product search/recommendation, catalog management, PLP, PDP, order/delivery, and coupon/promotion features. Utilizing cutting-edge technology to ensure service stability while listening to user feedback and resolving issues swiftly and flexibly.

Join Our TeamAs a Product Server Developer at Toss, you will be one of the pioneering members of our team, gaining diverse experiences as we venture into the offline payment industry.We are excited to shape the history of payment systems, innovating the payment ecosystem with enthusiasm.You will collaborate with various colleagues, including Business Development Managers, Purchasing Managers, and Hardware Engineers, to successfully launch top-tier payment devices.Your ResponsibilitiesDesign and develop product servers that create digital innovations in the offline payment market, providing beautiful payment experiences.Handle all aspects of system service design and operations to ensure we deliver utmost value.Utilize cutting-edge technologies to maintain stable service operations, swiftly addressing user feedback and challenges.Ideal CandidateYou have experience designing and operating high-availability, scalable systems.You possess a background in developing systems that handle large-scale, real-time traffic.You have faced and resolved system failures, demonstrating your problem-solving skills.You approach your work with a strong sense of ownership and dedication, treating the service as 'your own'.You enjoy sharing insights and ideas gained from service development and are eager to embrace continuous technical challenges.Resume TipsDetail your experience in developing solutions that efficiently and reliably handle high traffic volumes.If you have proactively identified and improved issues, please specify the technologies used and the extent of improvements.Include any experience you have in participating in the early stages of service development.Experience in developing B2C services based on the Spring Framework is a plus.Technologies We UseKotlin, Java, GradleNetty, Spring MVC, Spring Webflux, Spring Boot, Spring Cloud Gateway, Spring Cloud ConfigJPA/Hibernate, MySQL, MongoDB, Hadoop, Redis, Memcached, ZookeeperKubernetes + Istio, Haproxy, NginxGoCD, ArgoCD, Consul, Vault, Git, Docker, Spinnaker, Jenkins, Ceph, HarborKafka, ELK, Prometheus + Thanos, InfluxData, Grafana

Join Our Dynamic Team! As a Server Developer at Toss Bank, you will collaborate in a squad with diverse professionals including Product Owners, Product Designers, Server/Frontend Developers, and Data Analysts to create exceptional banking services. We foster a unique development culture and autonomous environment, striving to deliver unparalleled services that transcend the limitations of traditional banking. Your contributions will ensure that our customers enjoy the best banking experience through Toss Bank's services. Your Responsibilities Revamp the existing complex monolithic banking system into a flexible and scalable Microservices Architecture (MSA). Engage in the development of new product launches and expand your expertise through collaborative development across various domains. Design and develop the core banking system innovatively, exploring new methodologies. We Are Looking For Proven experience in developing services using Java or Kotlin within the Spring Framework. Experience in designing databases with Oracle, MySQL, or similar technologies while planning and operating services. Familiarity with transaction and flow control methodologies. Demonstrated ability to proactively learn new technology stacks or improve existing systems. Experience in developing and operating in a core banking environment is a plus. Even without financial sector experience, candidates who have improved inefficient system structures are encouraged to apply. Please Note Any discrepancies found in submitted documents or disciplinary issues in work history may lead to the cancellation of employment. Applicants with disqualifying reasons according to Toss Bank's employment regulations may also face cancellation of employment. We provide preferential treatment for disabled individuals and veterans in accordance with relevant laws.

Join Our Innovative Team! Toss is a dynamic company comprised of various domains, each operating independently yet collaboratively. Our structure includes six domains: Ads & Benefits, Commerce, Pay, Financial Marketplace, Foundation, and Growth. The Ads & Benefits domain began its advertising journey in September 2022, launching a diverse range of advertising products including video ads, banners, live shopping promotions, luck quizzes, and push notifications for money alerts. Within the domain, teams such as Benefit Silo, Ads Platform Team, Ads Performance Team, and Monetization Silo work seamlessly as one. Having experienced explosive growth since the second half of 2022, we are now focused on refining our targeting capabilities to ultimately establish the premier advertising platform. Your Role: Design and develop the Product server utilized by numerous Toss customers. Leverage your knowledge of the advertising domain to create products centered around Ad Serving & Delivery, User Targeting, and ML Logic-based Bidding & Auction systems. Utilize cutting-edge technologies to ensure service reliability while actively listening to user feedback and promptly addressing issues. What You Should Know: This position is ideal for individuals with a background or interest in advertising. While similar to the Server Developer (Product) role in service development, this position specifically focuses on the Ads & Benefits domain. For those interested in flexible placement prior to joining, please consider applying for the [Server Developer (Product)](https://toss.im/career/job-detail?job_id=4071141003) position. Please note that the Toss community is not currently hiring for military service personnel (Industrial Technical Personnel, Professional Research Personnel). Transfers or new hires are not possible. Desired Qualifications: Experience in designing and operating high-availability, scalable systems. Background in developing systems that handle large-scale, real-time traffic. Experience dealing with system failures and resolving issues. A strong commitment to ownership and pride in your work, treating the service as “your own”. Willingness to share insights and ideas gained from service development and an eagerness for continuous technical challenges. Experience in the advertising sector is a plus. Technologies We Use: Kotlin, Spring MySQL, MongoDB, Hadoop, Redis, Kafka, Elasticsearch Our Hiring Process: Application Submission > Technical Interview > Cultural Fit Interview > Reference Check > Offer Discussion > Final Selection and Onboarding A Message to Future Colleagues: “We are looking for individuals eager to grow the Ads & Benefits domain together!” Having started from scratch, Toss's advertising business is now prepared for significant growth, creating a platform for advertisers and offering a variety of user-friendly advertising products.

Join Our Dynamic Team!The Server Developer (Product) role is part of Toss's innovative Silo team, comprising 6-8 diverse professionals, including product owners, designers, developers, and data analysts, collaborating like a startup with autonomy.As our user base grows, we have dedicated server developers ensuring stable operations. Unlike silo teams focusing on rapid experimentation, this role supports a variety of services across Toss.Your Responsibilities Include:Designing and developing the Product server used daily by countless Toss customers.Offering over 50 services since the inception of our convenient remittance service in 2015, including financial status checks, pedometers, and fortune quizzes.Utilizing trendy technologies to ensure services run smoothly while listening to user feedback to quickly and flexibly resolve issues.We Are Looking For Individuals Who:Have experience designing and operating high-availability, scalable systems.Possess a background in developing systems that handle large-scale real-time traffic.Have faced challenges and resolved issues during system failures.Are passionate about their services and approach their work with a sense of ownership.Enjoy sharing insights and ideas gained from service development and are eager for ongoing technical challenges.Services You Will Contribute To:Loans: Create services that allow users to easily compare and apply for various loans, expanding offerings such as personal loans, mortgage loans, and card loans to ensure Toss is top of mind.Marketplace: Develop essential services for users, like card benefit comparisons, investments, and auto insurance.Payments: Work on Toss's convenient payment system, TossPay, handling everything from online and offline payments to new payment method development and promotional activities.Commerce: Enhance Toss's commerce services to create value for both users and sellers, including group purchases and admin services for sellers.Benefits: Develop innovative services in the app tech space, including pedometers, live shopping, luck lotteries, and collaborative point-earning activities.Ads: Expand Toss's advertising business by reliably serving high-traffic products and developing integrations for ad networks.Home: Create services for the homepage that first engages Toss users, analyzing assets, income, and spending patterns while connecting them to relevant Toss services.

Join our innovative team at tosscareers as a Server Developer (Foundation). In this role, you will be instrumental in building robust server-side applications that drive our technology platform. You will collaborate with cross-functional teams to develop scalable solutions that enhance user experience.

About the Financial Marketplace Domain Toss organizes its work into several domains, each running its own business and product lines. The Financial Marketplace domain delivers a range of financial services, including loans, credit cards, insurance, and account management. This team helps customers address financial needs directly within the Toss platform. The domain is expanding into real estate and mobile services, aiming to address broader customer needs beyond traditional finance. Business and product teams work side by side, moving quickly to experiment with and scale new offerings alongside various partners. Learn more from the Financial Marketplace Leader Article. What You Will Do Design and operate products in the financial domain with a focus on scalability and stability. Work closely with partners to solve real problems, seeing the direct impact of your work and growing quickly. Move fast to achieve medium- and long-term goals for the domain, leading change where needed. Drive the adoption of AI Agent-based automation throughout the domain and help grow the platform. Who We’re Looking For At least one year of hands-on experience in software development. Background in designing and running high-availability, scalable systems. Experience building systems that handle large-scale, real-time traffic. Interest in, or experience with, AI-driven operational automation. Platform engineering design experience is a plus. Knowledge of financial products (such as loans, cards, or insurance) is helpful. Interest or experience in real-time data processing or Flink is beneficial. Experience setting up test infrastructure or mock servers is a plus. Understanding of regulatory or compliance requirements, or experience designing governance, is valued. Technologies in Use Kotlin Spring MySQL MongoDB Hadoop Redis Kafka Important Application Notes Candidates will be considered first for roles in the Financial Marketplace domain. Depending on interviews, skills, and internal needs, offers may be extended for other teams. If interested in roles outside this domain, see the Server Developer (Product) opening. Any false information on a resume or disciplinary issues during employment may result in cancellation of the hiring process. Hiring may be canceled according to Toss regulations if candidates fall under restricted or disqualifying categories. Hiring Process Application Submission Job Interview Cultural Fit Interview Reference Check Compensation Discussion Final Acceptance and Onboarding Working at Toss "To connect everyone with easier and more convenient finance." The Financial Marketplace Domain at Toss starts by questioning whether products truly serve users. Teams across business, product, and engineering work as one to build solutions. Perseverance and a collaborative approach to defining and solving problems, especially when navigating financial regulations, are valued here.

Join Our Dynamic Team!As a Server Developer (Product), you will be a vital part of Toss Bank's innovative Squad, collaborating closely with Product Owners, Designers, and Data Analysts to design and develop cutting-edge financial products.You will work with a dedicated group of 3-5 Server Developers within your squad, actively contributing to the development of loan, deposit, and card products. Our environment is designed to nurture growth, making it an ideal place for junior developers.With limited experience in financial sectors, our Server Developers are primarily from promising IT companies and startups, questioning traditional banking norms and designing products that challenge the status quo.Your Responsibilities Include:Developing efficient methods to present complex banking systems in a streamlined manner to our customers.Creating fast, flexible, and scalable systems that enhance customer experience.Building robust and secure systems capable of handling large traffic volumes reliably.Proposing and implementing innovative banking service ideas from design to development.Developing internal management web services to enhance banking system innovations alongside customer-facing services.We Are Looking For:Experience in developing services based on the Spring Framework using Kotlin or Java.Ability to quickly grasp business requirements and design data models and APIs proficiently.A mindset that embraces change and a desire for continuous growth.A collaborative spirit, eager to share knowledge with colleagues.Experience in managing high traffic systems is a plus.Familiarity with Redis and Kafka is advantageous.Please Include in Your Resume:At least one concrete example of a project you participated in, showcasing your contributions and how you overcame challenges.A detailed account of your problem-solving capabilities, including the definition of issues you faced and your attempts to resolve them, along with the outcomes.Any experience handling large-scale traffic or initiatives aimed at improving outcomes compared to previous benchmarks.Your growth aspirations as a developer and the efforts you are making toward achieving them.Technologies We Use:Kotlin, Java, GradleNetty, Spring MVC, Spring Boot