Software engineer focused on problem-solving and the completeness of services without limiting tech stack. Actively contributes from the planning stage to prioritize user convenience. Currently responsible for the overall billing and user-side services across multiple MSA environments.
Experience
LG Uplus VoltUp
Sep 2024 — PresentTech Innovation Tribe, Back-end
Designed a Multi-PG and Point combination payment system using the Strategy pattern—unifying multiple payment gateways via a single interface. Ensured settlement stability through DLQ and multi-step unpaid batch processing. Architected and implemented Kakao T platform integration—orchestrating account authentication and payment flows across 4 distinct MSA domains. Developed promotion (coupon/point) systems to increase customer retention, improved reliability of government roaming service, public certificate processing and fallback logic (circuit breaker) for vehicle lookup API AI workflow standardization, auto-doc generation, DX infrastructure
Kakao Style
Jun 2022 — Sep 2024Pricing System, Back-end
Final pricing service, N:M product matching, Zigzag membership/mileage, and shopping EP integrations (Naver/Google/YouTube). Pipelines for external price collection and competitive position automation.
Storelink
Mar 2021 — Jun 2022R&D Engineer
Product data collection, keyword ranking, and services including Friday/Pugshop.
Whatap Labs
Mar 2019 — Mar 2021Front-end Engineer
Frontend for Whatap monitoring platform (Infrastructure, JVM applications, Kubernetes, etc.).
Hamschout
Aug 2017 — Aug 2018SW Engineer
Developed a platform matching influencers with businesses.
OpenBridge
May 2016 — Jul 2017SW Engineer
AlarmTalk (alarm + chat) and Potion (photo editing + missions) apps, and web development.
Projects — LGU+ VoltUp
Multi-PG billing & settlement reliability
Oct 2024 — PresentLed billing design from the start; expanded from a single PG to KakaoPay, Toss Payments, and Kakao T with shared error-code mapping. Layered arrears batches, retry→DLQ, and NACK recovery; SQL keepalive and pool tuning.
Coupon & point promotion platform
Coupon: Jul 2025 / Points: Aug–Oct 2025Backend for coupons/points covering Nexen/Toyota/Bluemembers-style promos; full-stack admin UI.
User-side Backend
Jul 2025 — PresentDeveloped core user-side backend features including Kakao T account/payment integration across 4 MSAs, PnC auto-charge, and unpaid-charge monitoring.
VoltUp Hybrid App (Flutter)
Dec 2024 — PresentLed Flutter hybrid delivery for 2.0; designed and implemented unified Android/iOS platform architecture and bridge patterns.
Roaming service reliability & performance
Feb 2026Reworked roaming card-state updates using billing arrears truth; removed redundant serialization; batched billing lookups; tuned retries per domain.
Developer productivity & DevOps
Oct 2024 — PresentAI-first reviews, mobile CI/CD hardening, remote Gradle cache, iOS TestFlight automation, obfuscation policy, Firebase distribution, STG payment cancel tooling for QA.
Projects — Kakao Style (2022.06 — 2024.09)
Mobile Proxy & Price Monitoring Report
Jan 2024 — Sep 2024Built a mobile proxy server pool to bypass crawling blocks and automated the price comparison pipeline.
N:M Identical Product Matching
Feb 2024 — Sep 2024Overhauled 1:1 matching to an N:M structure to match identical products across all stores and types.
Final Pricing (Unified Calculation Logic)
Dec 2023 — Sep 2024Consolidated scattered price calculation logic into a single API for consistent coupon, promo, and discount application.
Membership & Mileage Migration
Apr 2023 — Jun 2023Redesigned membership tiers for retention and migrated legacy Node.js services to Spring Boot.
Naver Shopping Engine Page & Lowest Price Update
Jun 2022 — Sep 2024Enhanced price competitiveness of Zigzag products for exposure on Naver Shopping price comparison.
Projects — Earlier experience
Friday analytics
Mar 2021 — Jun 2022Backend development for commerce keyword analytics service.
Whatap monitoring FE
Mar 2019 — Mar 2021Developed integrated monitoring dashboards to visualize data collected from various agents (App, Server, DB, Container).
Influencer platform
Aug 2017 — Aug 2018Developed an influencer marketing platform for campaign management and influencer matching.
AlarmTalk (Android)
May 2016 — Aug 2017Social alarm service combining alarms and chat for mutual wake-up calls.
Potion (Android)
May 2016 — Aug 2017Mission-based photo filter app where users earn points for printing photos.
Community & Speaking
Codeit Backend Course Mock Interview Mentor
Sep, Dec 2025Conducted technical and mock interview mentoring for backend developer bootcamp graduates.
Kernel360 Backend Mentor (1st ~ 5th cohorts)
Dec 2023 — Aug 2025Participated as a mentor for the 1st through 5th cohorts, guiding full-stack collaboration and enterprise problem-solving projects to foster job-ready developers.
Kakao Tech Campus Backend Mentor (2nd)
Jun 2024 — Aug 2024Participated as a mentor for the 2nd cohort of Kakao Tech Campus backend track.
Kookmin SW-Centered University Mentor
Mar 2024 — PresentParticipated as a mentor for Kookmin University's SW-centered university program.
Hanyang ERICA SW Startup Lecture
Feb 2024Gave a talk on "Effective Backend" for the SW startup lecture series.
Boostcamp 8th Backend Mentor
Nov 2023 — Dec 2023Mentored two iOS service project teams for Boostcamp.
Hanbit N MSA — Monitoring session
Dec 2023Led the 9th session on Monitoring for Hanbit Media's seminar series.
Boostcamp 7th~8th Backend Reviewer
Sep-Oct 2022 / Sep-Oct 2023Conducted campus meetings and code reviews for web backend campers (7th and 8th cohorts).
UbuCon Korea 2023 Speaker
Sep 2023Presented on "Building a Development NAS using WSL".
SW University Joint Hackathon 2023 Mentor
Jun 2023Provided FE/BE mentoring and career counseling as a hackathon mentor.
IT'sTime (College IT Union) Backend Mentor
May 2023 — Jul 2023Conducted seminars and project mentoring for university students.
Programmers School JAVA Mentor (11th)
Mar 2023 — Apr 2023Provided Q&A, code reviews, and video mentoring.
Gyeongbuk SW High School React Lecture
Sep 2022 — Oct 2022Conducted a React lecture series (Explanation > Clone Coding > Project) for vocational high school students.
Ubuntu Korea Community Infra Manager
Mar 2018 — May 2021Managed infrastructure (Forum, Wiki, ASK, Mail server) for the Linux community.