Backend Software Engineer

About The Job The client is hiring for this role, and Harper, an AI career agent, is on your side of the table. Skip the application form: just talk to Harper, and in a few minutes it learns your background, then puts the strongest profiles directly in front of the client's decision-makers. 👉 Start with Harper Job Title Software Engineer, Backend Salary Competitive compensation, calibrated to experience Location Seoul, South Korea, on-site Company Description The client is the team behind Korea's largest hyperlocal service: an app tens of millions of people use to connect with their neighbors. It started with secondhand trading and has grown into the country's biggest local community platform, valued around $2.4B. The community organization builds the products where neighbors share what is happening around them, from interest groups and local hangouts to apartment communities, and it is one of the most active areas of the product today. Engineers here work as product engineers. You do not stop at the server: you help decide what to build and why, ship it, measure the result, and improve it. Small tasks go to AI agents; your energy goes to the harder problems, and you own the quality of everything that ships. What You'll Do Start from real neighborhood problems and build features from the planning stage, not from a handed-down spec.Build and operate servers that handle thousands of requests and messages per second, and own deployment, monitoring, and incidents end to end.Design architecture at every level: an API and domain model for a single feature up to service-wide structure and cross-system integration.Design database schemas, migrate them safely, and keep queries fast at scale with caching and indexing.Embed and index community content so AI can surface the right local information to the right person.Build and run the shared platform (frameworks and common modules) that the whole community service runs on. Required Qualifications 3+ years of server application development, or equivalent skill.You have owned a live service for a year or more, not only shipped and moved on.Strong with JVM languages (Kotlin, Java) and Spring.Hands-on with relational databases and caches, and you think about what keeps a server stable.You have measured and improved the system metrics that matter, and you push problems to the root cause.You think about which metrics and user experiences your work changes, and you can walk away from work when the direction is wrong. Nice to Have You run your own AI workflow with coding agents like Claude Code or Codex.You reach beyond the server app when the product needs it: web apps, data, internal tools.You have solved problems outside your familiar language or platform.You use what you build, and you improve the product from your own friction.You have grown a product through A/B test design and analysis. Tech Stack Kotlin and Spring on the server, TypeScript and React on the web, gRPC and OpenAPI, Kafka and RabbitMQ, MySQL, Redis, and BigQuery, OpenSearch for search and embeddings, Datadog, Grafana, and Sentry for observability, plus LLM integration through Spring AI and agent work in Node.js. You are free to introduce the tools you believe the problem needs. Why Join Your work reaches one of the largest active user bases in Korea, and you hear from those users directly.Full ownership from planning to production, backed by well-designed infrastructure so you focus on the product.An AI-native engineering culture: build the industry's best AI-leveraged workflow and share it.Colleagues who are strong across engineering, data, design, and product, and a culture of autonomy and responsibility.