Blog

Introduction We have many servers in our environment. There are not just one or two, but over 100 servers. And universally, Nexus is running on those servers. Instead of downloading external libraries or packages directly from the internet each time, a nearby Nexus acts as an 'intermediate repository'

Subscription Design of a Platform Deploying Itself Consistency Issues and Solutions Encountered in Vizend Kollex Subscription's Distributed Deployment 1. Background and Problem Definition Vizend Showcase is a platform that provisions Kollex (a deployment unit bundling multiple microservices) on Kubernetes clusters at the Pavilion (tenant) level using a GitOps

1. Background In a recent project, we encountered various issues while operating the program, such as nodes being in a 'NotReady' state in 'kubectl get nodes', 'kubectl exec' becoming unresponsive, and Pods suddenly changing to 'Evicted' status. Therefore, based on the four

When designing systems in industrial IoT or robotics environments, you inevitably face the challenge of processing vast amounts of sensor data and control commands in real-time. ROS2 (Robot Operating System 2) can be utilized to address these issues. Although ROS2 has 'Operating System (OS)' in its name,

1. Introduction I am developing a real-time chat service where people gather in a chat room to exchange messages and share photos. Like a common messenger, this service displays the messages sent by others on my screen instantly without needing to refresh. The first question that arises when creating

1. Overview This article summarizes the optimization experience related to mass request processing in a first-come, first-served application system, such as course registration or reservation requests, centered around DB transactions. The system begins right after the application starts.Focus on tens of thousands of requests in a short

The pressure of schedules and the realistic pitfalls of domain design When starting a new project, many developers intellectually understand the value of Domain-Driven Design (DDD) but often opt for pragmatic compromises. This is especially true under the pressure of deadlines that demand a rapid business launch, making it

"I thought that if I just threw the data to the LLM, a document would be quickly produced," and from that moment, the actual problem-solving began. In a recent architecture consulting project, I had to write a large service definition document that organized dozens of business boundaries

1. Introduction While carrying out the project, we developed a feature that allows users to download data viewed on the screen as Excel. Not just exporting data,but providing results in Excel that are as similar as possible to what the user sees on the screenwas the requirement. For example,

I have mainly been engaged in publishing work in a web environment. I have experience with responsive web work, but this is the first time I have built and implemented UI specifically in a mobile environment. Initially, I thought that mobile would not be much different since it is also

In an environment where multiple product lineups must be developed, operated, and expanded simultaneously, practical designers face structural issues that need to be addressed. By deeply extending the concepts of the three core brand architecture models (House of Brands, Branded House, Hybrid), we define the practical connections between business context

Introduction During a recent project, we implemented various Form screens based on React Hook Form (RHF) and Material UI (MUI). At the beginning of the project, we used to build common Field components to maintain consistency in the Form UI. <Field.Text name="name" label="Name&

Background In the development environment of the project, there were constraints that made it difficult to directly apply the Swagger library to the client's services. While it is possible to automatically generate API specifications based on Controller and DTO using Springfox or springdoc-openapi in a typical Spring-

Introduction Over the past few months, we have been implementing our internal design system, VUI (Vizend UI). VUI is a common language and promise that ties together designers and developers, allowing them to create products in the same way. It is a design system that weaves together design tokens, components,

Problem Definition In the Lakey project, we manage external events using the Vello module of the in-house messaging framework Prologue to store these events and utilize them in the LLM context. The event converter provided by Prologue, 'TypeAwareEventConverter', reads the 'payloadClass' value from the header

The Reflection of a Lazy Backend Developer Dynamic CMS Design In January 2026, the project I joined after returning to headquarters was the 'Tourism Content Management System (Pinlime).' We were in the process of reworking it on a modern architecture based on a project that had been applied

As we began implementing the payment module, the first concern we faced was not simply 'how to call the payment approval API.' The core issue was 'whether we could provide a consistent payment experience without disrupting the service's payment flow, regardless of which payment gateway

1. Introduction It's easy to think of Git branches as just a "tool for dividing features," but in actual work, branch strategy is directly connected to collaboration methods, development environment deployment and testing, QA validation, operational deployment, and hotfix responses. In environments where multiple people are

1. Introduction In the previous work, we dealt with the structure of separating the LLM automatic translation function into an asynchronous event flow. Instead of directly calling the LLM within the save request, we configured it to publish events in situations where translation is needed and perform the translation in

As the project size increases, it becomes more important to manage state and handle asynchronous requests efficiently than simply implementing features. Particularly in React-based applications, multiple components share the same data and make API calls based on various state changes, which can lead to unexpected duplicate request issues as

1. Introduction: Challenges of Backfill Architecture for Large Data Transfers In modern distributed system architecture, the reliability of data pipelines is directly linked to the survival of services. In particular, time series data generated in IoT, finance, or real-time monitoring systems often requires throughput of tens of thousands of

1. Introduction When developing a service, there are times when the time spent contemplating the aftermath is longer than that spent implementing the interface. I experienced this while developing the review feature for a recent tourist attraction content service. The review feature allows users to write their own reviews and

- The use of AI has accelerated code and document writing, but it does not directly translate to the team's progress. To connect an individual’s work speed to the team’s productivity, we assess the absorptive capacity required, based on the criteria of detectability, traceability, and recoverability. At

1. The Beginning of the Problem: Rising Storage Costs As the service operation period increased, the MongoDB storage capacity also continuously expanded. Due to business requirements, we couldn't delete the already created data, but keeping all the data in regular storage was becoming a significant cost burden. In

1. Overview This project required the introduction of a feature that detects anomalies in ship sensor data and generates alarms. To implement this, a new batch logic was developed to query sensor data for each ship, detect conditions for alarm generation, and then generate alarms. This was executed in a