CV (Curriculum Vitae)

Seunggon Kim

I’m passionate about software engineering for SOTA architecture, programming and theory also.

Contents

Work experience | Education | Projects | Skills | Awards | Publications | Languages

Work experience

Tech lead, Kinolights Inc. - Korea
Mar. 2022 - Present
  • Developed the back-end of Kinolights.
    • Built a notification server to control both in-app notification center and push notifications such as FCM.
    • Designed and implemented a community server to post, comment, respond and search. The feature-rich post includes link preview, poll, image/video upload, and tagging.
    • Built a search engine on top of Elasticsearch with support for initial consonant search, phoneme-level matching, synonym expansion, typo correction, and trend-aware scoring.
    • Developed a metadata collection system combining crawling and third-party API integration to enrich internal datasets.
    • Implemented a point system that rewards user actions and enables event participation, including supporting modules for winning probability calculation, aggregation, and redemption tracking.
    • πŸ“š NestJS, RxJS, TypeORM, GraphQL, MySQL, Elasticsearch, Redis, Kafka, RabbitMQ, BullMQ, Amplitude, Datadog, Sentry
    • ☁ AWS - RDS, ElastiCache, OpenSearch, MQ, MSK, Fargate, ECS, SQS, SNS, SES, Lambda, Batch, EventBridge, WAF, Route53, CloudFront, S3, MediaConvert, CloudWatch
  • Improved SEO to increase monthly Google search clicks from 250K to 800K through technical optimizations and content restructuring.
  • Gradually modernized a legacy mobile application through a phased transformation.
    • Consolidated separate Android and iOS web apps into a single Flutter-based web app, reducing maintenance costs and improving rendering performance.
    • Further evolved the application into a full-featured native app using Expo and React Native to enhance cross-platform capability and user experience.
    • πŸ“š Flutter, React Native
  • Maintained overall service infrastructure including cost optimization, deployment pipelines, and resource monitoring.
  • Implemented event tracking pipeline with Amplitude: managed quotas, user identity mapping, event schema, dashboard guidelines, and internal onboarding.
Software engineer, ActionPower Corp. - Korea
Jul. 2021 - Feb. 2022
  • Built a stable and scalable Speech-To-Text (STT) pipeline.
    • Achieved high availability by orchestrating multiple kubernetes clusters consisting of on-premise Airflow and Google Cloud Composer.
    • Increased inference throughput by leveraging NVIDIA Triton for parallel execution.
    • πŸ“š Airflow, Microk8s, NVIDIA Triton, Kubernetes, Python, GCSFuse
    • ☁ GCP - Composer, GKE, GCS
  • Designed and implemented a real-time streaming STT service.
    • πŸ“š Spring boot, RxJava, Kafka stream, Redis, Vosk, Kaldi
  • Developed the back-end of Daglo that is B2C/B2B/B2G service providing STT.
    • Reduced operational costs by adopting Apache Airflow and optimizing infrastructure resources.
    • Built a data warehouse using Elasticsearch and Kibana for efficient data storage and visualization.
    • Developed a transcript search engine using Elasticsearch’s Korean analyzer Nori and TF-IDF for relevance ranking.
    • πŸ“š Express.js, FastAPI, Firebase, Elasticsearch
    • ☁ GCP - GKE, GAE, GCS, GSR
  • Developed the back-end of Atend for video conference and following STT.
    • πŸ“š NestJS, RxJS, Firestore, Redis, Twilio
    • ☁ GCP - GAE, GCS
  • Implemented an automated end-to-end testing environment for continuous integration.
Software engineer, LINE Plus Corp. - Korea
Jun. 2019 - Jul. 2021
  • Developed the back-end of LINE messenger.
    • Implemented features including read-only chatroom, adult-only chatroom, abusive user detection and so on.
    • Improved the performance of LINE app by introducing conditional chat prefetching, which reduced total blocking time.
    • Reduced Elasticsearch get/search latency by 2x through query and cluster optimization.
    • Contributed to Armeria to expose internal metrics for server monitoring. And integrated Prometheus-compatible metrics and built Grafana dashboards for service observability.
    • Identified and resolved performance bottlenecks using profiling tools such as heatmaps, thread dumps, and heap dumps.
    • Manually upgraded Elasticsearch from version 5.0 to 6.3 across two clusters (active-standby configuration).
    • Built a fault-tolerant Kafka producer with logging-based recovery to minimize message loss.
    • Developed a back-office Content Management System (CMS) for internal operations.
    • πŸ“š Spring, Java, RxJava, MySQL, Redis, Elasticsearch, HBase, Kafka, Zookeeper, Armeria, Central Dogma, Retrofit, Thrift, Protobuf, Jenkins, Ansible, Zipkin, JMH, Grafana, Prometheus, Micrometer, Dropwizard
  • Developed CI/CD pipelines and automation processes.
    • Implemented and stabilized end-to-end (E2E) tests to verify behavior and server push on SPDY called LEGY.
    • Built a periodic ranking/trending data generation system using Elasticsearch.
    • Developed custom load-testing programs using Gatling to simulate high-load conditions.
    • Built a dedicated monitoring server to handle complex conditions not expressible in PromQL, with alerting bots integrated into Line Messenger and Slack.
    • πŸ“š Spring Batch, Flask, Gatling, Java, Python, Kotlin, Scala
Senior researcher, Coinplug Inc. - Korea
Oct. 2017 - Jun. 2019
  • Developed the back-end of cryptocurrency exchange.
    • Enhanced bidding API performance by 200x through architectural redesign.
    • Implemented KYC (Know Your Customer) authentication system.
    • Developed deposit and withdrawal processing for KRW and cryptocurrencies.
    • Continuously integrated newly listed cryptocurrencies into the exchange platform, ensuring timely support and smooth trading operations.
    • πŸ“š Spring, MySQL, RabbitMQ
    • ☁ AWS - EC2, MQ
  • Designed and deployed an Ethereum proxy server that delegates user transactions to the blockchain network.
    • πŸ“š Go, Ethereum
    • ☁ AWS - Lambda, API Gateway
  • Developed decentralized applications (DApps) that interact with smart contracts via Web3.
    • πŸ“š Solidity, Ethereum, IPFS, React
  • Implemented API clients for trading and monitoring the tendency.
    • πŸ“š Go, React
  • Researched blockchain technologies and security issues on all sides such as platform, smart contract, GDPR and so on.

Education

  • M.S. and Ph.D. Candidate, CE, Seoul National University, Korea, 2017
  • B.S., CE, Kwangwoon University, Korea, 2012
  • Extra
    • Self-Driving Car Nanodegree Term1 and Term2, Udacity, 2017
    • Software Maestro, Ministry of Science, Korea, 2013

Projects

  • Open source
    • Armeria - a microservice framework to easily build any type of technologies including gRPC, Thrift, Retrofit and so on.
    • Python client for Central Dogma - a Python client for Central Dogma that is highly-available version-controlled service configuration repository based on Git, ZooKeeper and HTTP/2.
  • Solo
    • Chewing Diet - iOS, Android, Web
      • ~10K total downloads and ~1K MAU.
      • πŸ“š Flutter, Firebase, Next.js, Tailwind CSS
    • μ˜€λŠ˜λΆ€ν„° 전곡면접 IT - iOS, Android, Web
      • a MCQ-based (Multiple Choice Question) study helper for IT interview.
      • πŸ“š Flutter, Firebase, Next.js, Chakra UI
    • Employee Stock Option Calculator - iOS, Android
      • πŸ“š Flutter, Firebase
    • MojiE - iOS, Android
      • πŸ“š Flutter, Firebase
  • Research
    • CPS-Sim, 2016 - 2017
    • ECU-level real-time simulator, 2013 - 2017
      • w/ Hyundai Motors
      • Support verification of application logic on vehicle
    • Component based design theory and control kernel for CPS, 2013 - 2015
    • Real-time system SW on multicore and GPGPU for unmanned vehicles, 2016 - 2017
    • Drone simulation for AED(Automatic External Defibrillator) delivery, 2017

Skills

  • Programming language
    • Java, TypeScript, Python, Go, Dart
    • Assembly, C, C++, C#, Kotlin, Scala, MATLAB, ML, Objective-C, Ocaml, Painless, PHP, Scala, Solidity, Tcl/Tk
  • Platform & Framework
    • Reactive
      • RxJava, RxJS
    • Back-end
      • [Java] Spring, Spring boot, Armeria, Guava, JUnit
      • [TypeScript] NestJS, Express.js, Node.js, Puppeteer, Jest
      • [Python] Airflow, FastAPI, Flask, Django, pytest
      • [Storage] Elasticsearch, Redis, MySQL, HBase, Firestore, DynamoDB, LevelDB, PostgreSQL, Zookeeper, Central Dogma, Ethereum, IPFS
      • [Stream] Kafka, RabbitMQ, BullMQ, AWS SQS
      • [Orchestration] Docker, Jenkins, Kubernetes
      • [Monitoring] Datadog, Grafana, Kibana, Prometheus, Sentry, Zipkin, Gatling
    • Front-end
      • Next.js, React, Vue.js, Tailwind CSS
    • App
      • Flutter, React Native, Nativewind
      • Tizen, Qt, Unity, Cocos2d, MFC
    • Vehicle field
      • [Simulator] CarSim, Torcs
      • AutoBox, AUTOSAR, EB Tresos, Odin, Simulink
      • FlexRay, CAN(Controller Area Network), CAN-FD
  • Protocol
    • HTTP/2, REST, GraphQL, gRPC, RTC, SSE, SPDY, Thrift, Websocket
  • Cloud service
    • AWS - RDS, OpenSearch, Elasticache, MQ, MSK, SNS, SMS, SQS, WAF, CloudFront, ALB, API Gateway, Fargate, ECS, EC2, Lambda, Batch, EventBridge, MediaConvert, CloudWatch
    • GCP - Composer, GAE, GCE, GCR, GCS, GKE, GSR, Memorystore
  • Tool
    • Github, Gitlab, Sourcetree, JSFiddle, Remix
    • Slack, JIRA, Trello
    • [Documentation] Confluence, Doxygen, Javadoc, Sphinx, Jekyll
    • [Analysis] async-profiler, Dr.Memory, Valgrind, Black Duck Hub
    • [Package manager] Gradle, Helm, npm, yarn, pip, dep
    • Hardware-related
      • CodeWarrior, GreenHills, TASKING, Trace32
      • Infineon(TC1797, TC275), STMicro(SPC56EL70), Freescale(MPC5606B), Raspberry Pi, Arduino
      • CANalyzer, CANDB, PCAN-USB, Vector(VN1640, VN7600)

Awards

  • 2nd prize, OSS grand developers challenge, National IT Industry Promotion Agency (NIPA), 2016
  • Best paper award, Korea Computer Congress (KCC), 2017

Publications

  • Kyoung-Soo We, Seunggon Kim, Wonseok Lee, and Chang-Gun Lee, Functionally and Temporally Correct Simulation of Cyber-Systems for Automotive Systems, in IEEE Real-Time Systems Symposium (RTSS), 2017
  • Wonseok Lee, Kyoung-Soo We, Seunggon Kim, Sangyoun Paik, Jonathon Soulis, and and Chang-Gun Lee, An ECU-Close Design/Verification Tool for Automotive Systems, in IEEE Real-Time Systems Symposium (RTSS@Work), France, 2017
  • Hyejin Joo, Kyoung-Soo We, Seunggon Kim, and Chang-Gun Lee, An End-to-End Tool for Developing CPSs from Design to Implementation, in The First International Workshop on Verification and Validation of Cyber-Physical Systems (V2CPS), Iceland, 2016
  • Seunggon Kim, Youngeun Cho, Sangyoun Paik, Chang-Gun Lee, PC-based Estimation of ECU Dynamic Memory, Korea Computer Congress, Korea, 2017
  • Wonseok Lee, Kyoung-Soo We, Seunggon Kim, Chang-Gun Lee, Simulator Structure for Lockstep ECU, Korea Computer Congress, Korea, 2017
  • Seunggon Kim, Kyoung-Soo We, Chang-Gun Lee, MATLAB Model-based ECU Code Auto-Generation Technique, KIISE, Korea, 2016
  • Seunggon Kim, Kyoung-Soo We, Chang-Gun Lee, Two-level Offset Technique for Verifying Reconstruction and Simulation, KIISE, Korea, 2015
  • …

Languages

  • πŸ‡ΊπŸ‡Έ English
  • πŸ‡―πŸ‡΅ Japanese (JLPT N1)
  • πŸ‡°πŸ‡· Korean (native)