Dongho Kang
강동호
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
(Tech 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
(Pricing 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
(R&D Engineer)Product data collection, keyword ranking, and services including Friday/Pugshop.
Whatap Labs
(Front-end Engineer)Frontend for Whatap monitoring platform (Infrastructure, JVM applications, Kubernetes, etc.).
Hamschout
(SW Engineer)Developed a platform matching influencers with businesses.
OpenBridge
(SW 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.
- Owned billing 0→1 as core engineer
- Designed vendor strategy pattern with abstract base classes to integrate 3 PG providers with unified interface
- GCP Pub/Sub DLQ pattern with custom annotation-based handler discovery for payment event resilience
- DLQ-based arrears processing and permanent arrears handling system — retry→DLQ, NACK-based auto-recovery to prevent settlement gaps
Coupon & point promotion platform
Coupon: Jul 2025 / Points: Aug–Oct 2025Backend for coupons/points covering Nexen/Toyota/Bluemembers-style promos; full-stack admin UI.
- Designed point wallet system with per-deposit expiration — separate wallet entity per deposit, aggregated balance with 7-day expiry-soon tracking
- [object Object]
- Hold→Confirm→Release 3-phase point lifecycle ensuring auto-restoration on payment failure
- Partner-specific promo rules — expiry, duplicate issuance, amount settings (Nexen/Toyota/Bluemembers)
- Promotion coupon issuance batch — designed and developed
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.
- Designed and implemented Kakao T account/payment integration across 4 MSAs (auth→user→billing→feapp) — OAuth2 account linking, 5-step card registration, payment approval/partial cancellation
- Vehicle registration service and PnC (Plug and Charge) authentication registration service
- Promotion coupon issuance batch — designed and developed
- Circuit breaker pattern for external certificate service — auto-disable on failure with recovery, force-reset fallback on total outage
Outcomes
- [object Object]
VoltUp Hybrid App (Flutter)
Dec 2024 — PresentLed Flutter hybrid delivery for 2.0; designed and implemented unified Android/iOS platform architecture and bridge patterns.
- Rapid Android/iOS hybrid delivery via Flutter for 2.0 launch (2025.03)
- JSBridge for frontend–hardware and app message communication — 20+ native bridge types
- ML Kit barcode scanner integration for QR code recognition improvement
- FCM-based push notification system
- In-app debug console development
Outcomes
- Launched within 2 months (Dec 2024 — Feb 2025)
- designed protocols for frontend to invoke native functions via JS Bridge
Roaming service reliability & performance
Feb 2026Reworked roaming card-state updates using billing arrears truth; removed redundant serialization; batched billing lookups; tuned retries per domain.
- Redesigned government card state updates from payment-response-based to billing arrears event-driven — selective updates only for arrears events
- Eliminated object→string→object serialization overhead; consolidated individual billing queries into batch lookups
- Government API error retry process — prioritized critical data (membership cards) over tolerably-lossy items (charger status)
Outcomes
- Improved data accuracy by rearchitecting card state update logic
- Reduced processing overhead by eliminating serialization and consolidating billing queries
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.
- Tailored Copilot (11 prompts), Claude Code (8 skills per MSA service), Cursor workflows across all repositories
- Gemini CLI for first-pass review load shedding
- Docusaurus + GitHub Actions auto-doc system with git-polling change detection
- Firebase App Distribution; QA self-serve payment cancel in STG/DEV
- Gradle generator for application-local.yaml
- Refactored Android Jenkins into shared libs; GCS remote cache; iOS GA/TestFlight pipeline; 300+ line R8 rules
Outcomes
- Reduced review overhead via automated first-pass AI review
- Shortened QA/deploy cycle and improved QA self-serve with Firebase Distribution
- Auto-doc system reduced manual documentation maintenance
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.
- Allocated per-port smartphone HTTP proxies and developed proxy pool lookup APIs
- Built smartphone control APIs (airplane mode, reboot) and automated rate limit management
- Constructed matching datasets between external (EP, lowest price) and internal products via AWS Athena
- Developed batch jobs for price advantage analysis and Excel report generation
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.
- Implemented dual caching for full matching lookups and served "Winner" data for search
- Developed matching batch jobs using AWS Athena for items with ≥99.5% image similarity
- Built matching lookup APIs for review integration and automated matching via Kafka consumers
Final Pricing (Unified Calculation Logic)
Dec 2023 — Sep 2024Consolidated scattered price calculation logic into a single API for consistent coupon, promo, and discount application.
- Analyzed complex pricing logic across all pages and designed a unified API
- Applied timeouts and circuit breakers for service stability
- Integrated with company-wide gateways to ensure price exposure consistency
Membership & Mileage Migration
Apr 2023 — Jun 2023Redesigned membership tiers for retention and migrated legacy Node.js services to Spring Boot.
- Zero-downtime migration of cormo.js legacy to Spring Boot via 1:1 DB migration
- Expanded tier calculation periods and developed tier-based mileage earn logic
- Optimized 3-month tier calculation by caching monthly totals and using cumulative sums
Outcomes
- Reduced DB load from 70% to under 30% through strategic caching
- Achieved zero-downtime deployment by ensuring legacy parity via integration tests
Naver Shopping Engine Page & Lowest Price Update
Jun 2022 — Sep 2024Enhanced price competitiveness of Zigzag products for exposure on Naver Shopping price comparison.
- Developed batch jobs for GMV-competitive products and integrated card promos/delivery badges
- Implemented logic to compare prices with competitors and consumed real-time Kafka updates
- Built backoffice tools and managed successful transition from CPC to CPS versions
Outcomes
- Halved batch processing time (4h → 2h) via event-driven product updates despite increased product volume
- Established the foundational final price calculation logic used for future pricing systems
Projects — Earlier experience
Friday analytics
Mar 2021 — Jun 2022Backend development for commerce keyword analytics service.
- Introduced Kotlin and WebFlux as the main tech stack for the entire team
- Replaced core service features with Friday search APIs (still in use)
- [object Object]
- Cross-architecture Docker builds (AMD64/ARM64) via buildx for AWS Graviton2 compatibility
- Puppeteer crawler API — page access, API query, tag selection, and JS function injection
Whatap monitoring FE
Mar 2019 — Mar 2021Developed integrated monitoring dashboards to visualize data collected from various agents (App, Server, DB, Container).
- Developed core components including TimeSelector and Server List dashboards
- Integrated legacy page handlers on React components and developed agent setup/install screens
- Implemented common data processing methods for better code reusability
Outcomes
- Reduced API polling churn for real-time dashboards and mitigated memory pressure on chart-heavy screens
Influencer platform
Aug 2017 — Aug 2018Developed an influencer marketing platform for campaign management and influencer matching.
- Developed influencer/blogger review and verification systems
- Built Naver search ranking lookup APIs
- Developed advertising reporting services for clients
Outcomes
- Automated advertiser–influencer matching, reducing contact overhead
- Improved marketing accessibility for small businesses and startups
AlarmTalk (Android)
May 2016 — Aug 2017Social alarm service combining alarms and chat for mutual wake-up calls.
- Led the development of AlarmTalk 2.0
- Implemented voice recognition and shake-to-wake alarm features
- Built the in-app alarm store system
Potion (Android)
May 2016 — Aug 2017Mission-based photo filter app where users earn points for printing photos.
- Developed core photo adjustment components (brightness, contrast, crop, etc.)
- Implemented photo filter engine and effects through design collaboration
- Integrated account systems and mission-related APIs
Community & Speaking
Conducted technical and mock interview mentoring for backend developer bootcamp graduates.
Participated as a mentor for the 1st through 5th cohorts, guiding full-stack collaboration and enterprise problem-solving projects to foster job-ready developers.
Participated as a mentor for the 2nd cohort of Kakao Tech Campus backend track.
Participated as a mentor for Kookmin University's SW-centered university program.
Gave a talk on "Effective Backend" for the SW startup lecture series.
Mentored two iOS service project teams for Boostcamp.
Led the 9th session on Monitoring for Hanbit Media's seminar series.
Conducted campus meetings and code reviews for web backend campers (7th and 8th cohorts).
Presented on "Building a Development NAS using WSL".
Provided FE/BE mentoring and career counseling as a hackathon mentor.
Conducted seminars and project mentoring for university students.
Provided Q&A, code reviews, and video mentoring.
Conducted a React lecture series (Explanation > Clone Coding > Project) for vocational high school students.
Managed infrastructure (Forum, Wiki, ASK, Mail server) for the Linux community.