Yongtak Kim

Product, data, and cloud support engineer

This portfolio collects the evidence behind a career that started with Android/iOS and backend implementation, expanded through OCR and image-processing R&D, enterprise data platforms, and Amazon OpenSearch support.

M.S. in Computer Science B.S. in Computer Science Computer Vision / Pattern Recognition

10+ yrs Software / Data Platform

Hands-on experience across apps, servers, databases, search, analytics platforms, and production operations.

4+ yrs AWS Analytics Support

Customer troubleshooting and escalation work for OpenSearch, Kinesis, QuickSight, and related analytics workloads.

2026 AI Workflow Tooling

Experiments with agent handoff, session recovery, document validation, and support-case workflow automation.

CS M.S. Computer Science Graduate Background

B.S. and M.S. in Computer Science with research experience in computer vision, pattern recognition, and image processing.

Career Timeline

From product teams to data platforms and cloud operations

The logos make the career path scannable first; the detailed sections below provide the evidence behind each role.

2022 - Present Amazon Web Services

Global cloud-services company I handle OpenSearch, Kinesis, and QuickSight customer issues, production-cluster stabilization, and escalation workflows.

2019 - 2022 CJ OliveNetworks

CJ Group ICT company I migrated and operated CJ ENM's big-data platform with OpenShift, IBM Cloud Pak for Data, Solr, MongoDB, Redis, Impala, and Hive.

2018 - 2019 G.Bike

Mobility service company I built Android/iOS apps, PHP APIs, MySQL schemas, admin tools, rental/return flows, and license-verification features.

2017 - 2018 Teamnova

Travel-app startup I maintained Popiece Android and led the iOS prototype for exchange rates, travel-expense UI, widgets, and calendar flows.

2013 - 2015 DioTek

Handwriting-recognition and mobile OCR company I implemented OCR, handwriting/printed-text classification, notebook-line removal, and color correction.

2011 - 2013 Digital Aria

Embedded GUI framework company I built rendering automation tests, 3D GUI features, face/finger recognition work, and handled R&D project coordination.

Selected Impact

I reduce large operational problems into repeatable procedures and tools

The common thread across OpenSearch production support, data-platform migration, mobile service operations, and AI workflow automation is the same: make problems observable, split decisions into smaller units, and turn repeated work into documentation or tooling.

OpenSearch SME Data Platform Mobile Products AI Workflow

AI Session Recovery

Tools for searching and resuming Claude/Codex agent work history.

HotDealppom

Product crawling, word statistics, and interest-based recommendation in an Android side project.

BikeNavi

Android navigation experiment with map APIs and real-ride demo videos.

Selected Work

Turning repeated support and development problems into tools and workflows

Mobile product development foundation — Built Android/iOS apps, REST APIs, database schemas, admin tools, map/location features, and product flows at G.Bike, Teamnova, and side projects.
Computer Science foundation — B.S. and M.S. in Computer Science, with research experience in computer vision, pattern recognition, image processing, and distributed-system problem analysis.
Image processing and OCR R&D — Implemented handwriting/printed-text classification, notebook-line detection and removal, color correction, rendering automation tests, and 3D GUI research work.
Data platform engineering — Worked on CJ ENM data-platform migration, OpenShift and IBM Cloud Pak for Data integration, and operations involving Solr, MongoDB, Redis, Impala, Hive, and RabbitMQ.
MCP-based support-agent workflows — Designed internal workflows connecting Slack, Outlook, wiki, ticket search, and local tools for response drafting, official URL checks, related-case search, aging-case triage, and escalation readiness checks.
AI collaboration quality gates — Turned user feedback on a narrow AI-proposed heuristic into `validate:content`, which checks that posts, tag listings, and portfolio detail content have public reachable paths before deployment.
AI Session Recovery — grouped claude-resume and codex-resume as one tool family for searching, summarizing, previewing, and resuming Claude Code and OpenAI Codex CLI work history.
linkedin-posting-mcp — A local MCP server focused on approval-based LinkedIn posting workflow, intentionally avoiding scraping and DM automation.
Aging Ticket Escalation AI Agent — An internal agent workflow combining long-ticket summaries, on-call screenshot OCR, manager-chain lookup, and professional escalation-email drafting.

AWS / OpenSearch

AWS Analytics Support and OpenSearch SME work

Recognition and Growth

2023.05: Recognized as an AWS Certified OpenSearch Subject Matter Expert.
2023.10: Promoted to Cloud Support Engineer II.
2024.12: AWSome All-Star recognition for stabilizing a large OpenSearch production cluster.
2026.02: Earned AWS Certified Solutions Architect - Associate.

Representative Customer Wins

Helped stabilize a large OpenSearch cluster affected by master-node resource pressure and unassigned shards through service-team escalation, monitoring, red-index diagnostics, and node-optimization guidance.
Supported a production launch migrating from HBase to OpenSearch by reviewing shard strategy, CloudWatch metrics, and replica-placement principles.
Investigated OpenSearch Ingestion Pipeline integration failures with an external SaaS by reproducing the issue and reviewing open-source code to isolate the authentication root cause.
Independently verified an OpenSearch Console Packages tab blank issue and prevented premature case closure caused by an incorrect deployment assumption.

Process Improvement and Automation

Aging-ticket escalation AI agent — Combined long-form ticket summarization, on-call screenshot OCR, manager-chain lookup, and escalation-email generation into a single workflow.
OpenSearch ELB log-analysis transition — Documented the new integrated environment and shared adoption guidance with Korea, Japan, and TPE teams.
AWS Countdown Premium Korea escalation runbook — Consolidated pre-event, event-day, and post-event roles and escalation contacts into a single reference.
Analytics onboarding material — Maintained wiki and broadcast-style materials for OpenSearch internal tools, CloudWatch metrics, and ELB access-log analysis.

Mentoring and Knowledge Sharing

Provided OpenSearch L3 SME consultancy, peer review, and escalation-direction guidance.
Mentored OpenSearch SME candidates through mock sessions, material curation, and case-based analysis practice.
Shared Analytics case studies and maintained internal best-practice wiki content.
Participated as an aging-case reviewer and PS / LP / Tech LOOP interviewer.

Detailed Resume

Career Record

Amazon Web Services 2022.04-Present · Cloud Support Engineer II / Analytics

Provide technical support for Amazon OpenSearch Service, Kinesis, and QuickSight.
Diagnose OpenSearch indexing, query performance, cluster scaling, ingestion, and real-time analytics architecture issues.
Collaborate with AWS service teams on escalation, long-term resolution, and customer communication quality.
Recognized as an OpenSearch SME, AWSome All-Star, and AWSome Builder.

CJ OliveNetworks 2019.07-2022.04 · Data Platform Senior Engineer

Led work on the CJ ENM big-data platform migration to IBM Cloud Pak for Data and OpenShift.
Analyzed the existing portal, adapted CP4D APIs, rebuilt Kubernetes project-creation APIs, and designed MariaDB changes.
Worked on CGV social-data service channel expansion, Solr storage issues, related-keyword jobs, used-car price prediction crawling, visualization solutions, and AI Competitor operations.

G.Bike 2018.06-2019.06 · Software Engineer

Developed electric-scooter rental and return flows, driver-license verification, bounty and payout flows, and long-term rental features.
Built Android/iOS app features, backend APIs, admin pages, and database tables.
Designed REST APIs, app scenarios, UI flows, and admin-page structures for Gmany and G-Bility services.

Teamnova 2017.07-2018.03 · Mobile App Lead

Maintained and fixed the Popiece Android travel-helper app while preparing it for Play Store release.
Led the newly formed iOS team and directly built the Popiece iOS prototype.
Implemented exchange-rate retrieval, travel-country data, popular-country flows, travel-expense UI, widgets, and calendar interactions.
Helped organize team development flow and product priorities for a mobile-app launch environment.

DioTek 2013.05-2015.05 · Image Processing Developer

Worked on image-processing development at a software company known for handwriting recognition, dictionaries, and mobile OCR.
Researched and implemented OCR algorithms applicable to Chinese, Japanese, and Korean text.
Built a handwriting-versus-printed-text classifier using eleven word-image features and a genetic algorithm for feature selection.
Implemented OCR preprocessing and quality-improvement work including notebook-line detection/removal, color correction, and dithering.

Digital Aria 2011.12-2013.04 · Research Engineer / R&D PM

Implemented rendering-test automation at an embedded GUI framework and 3D UI technology company.
Worked on context-aware 3D GUI, face/finger recognition, Android modules, and related R&D tasks.
Coordinated external vendors, partner institutions, schedules, and deliverables as a KOCCA national R&D project PM.
Handled implementation, testing, documentation, and collaboration before research outputs moved toward productization.

Side Projects

Side Project Record

AI Session Recovery claude-resume / codex-resume

Shared problem — recover useful work memory from long local JSONL session logs without manually opening every conversation.
claude-resume — Python/Textual two-panel TUI that finds Claude Code sessions through LLM-generated summaries and resumes the selected conversation.
codex-resume — Windows-friendly Node.js tool for searching OpenAI Codex CLI session logs and resuming a selected session reliably.
Implementation points — timestamp-based sorting, recursive self-invocation filtering, Windows CMD/PowerShell UTF-8 handling, and dependency-light picker/doctor/list/index/resume flows.

linkedin-posting-mcp / AI Workflow

Designed around LinkedIn API permission constraints, using approval-based drafts and posting checklists instead of automatic posting.
Documented agent handoff, session recovery, public/private repository boundaries, and adaptive-layout decisions as AI Workflow notes.
After a portfolio-detail regression, replaced brittle node-shape checks with an explicit content-reachability manifest enforced by GitHub Actions.

Early Android Projects

HotDealppom — Android/PHP/MariaDB recommendation experiment collecting product data from 11st, Coupang, and ppomppu, then testing Hadoop, Flume, MapReduce, and KoNLPy-based word statistics.
BikeNavi — Bicycle navigation project covering planning, LAMP server, database, Android app, Google Maps, Tmap, and social API integration.
Group Contacts — Early Android contact-management project focused on animation and address-book UX learning.

Skills

Core Capabilities

AWS Analytics operations and troubleshooting: OpenSearch, Kinesis, QuickSight, CloudWatch, S3, EC2, IAM.
Distributed-system and data-pipeline troubleshooting, query optimization, ingestion design, and enterprise migration.
AI-assisted engineering workflows using Claude Code, Claude API, OpenAI Codex CLI, MCP, and local automation tools.
Android, iOS, Python, Kotlin, PHP, C++, MySQL/MariaDB, Hadoop, Solr, Elasticsearch/OpenSearch, Redis, MongoDB, Impala, Hive.

Education / Research

Education, Certifications, Research

Hanyang University, M.S. in Computer Science (2010.03-2012.02, 4.14/4.50)
Korea Polytechnic University, B.S. in Computer Science (2006.03-2010.02, 4.25/4.50)
Dongbuk High School (2002.03-2005.02)
AWS Certified Solutions Architect - Associate, Amazon OpenSearch Service Subject Matter Expert, OCP 10g, Engineer Information Processing.
Research experience in computer vision, pattern recognition, image processing, infrared-image segmentation, and stereo-image feature matching.
Military service: Technical Research Personnel program (2012.02.21-2015.02.20).

Full Records · Open full career, project, academic, and statement archive

Full Records

Full Career, Project, Academic, and Personal Statement Record

Career Details

Amazon Web Services (AWS) 2022.04-Present · Remote · Analytics

Company: global public cloud service provider.
Role: Cloud Support Engineer II (2023.10-Present), Cloud Support Engineer (2022.04-2023.10).
Work: technical support for OpenSearch, Kinesis, and QuickSight; distributed-system diagnosis; customer architecture guidance; service-team escalation.
Technologies: Amazon OpenSearch Service, Kinesis, QuickSight, CloudWatch, S3, EC2, IAM, query optimization, ingestion pipelines, English technical communication.

CJ OliveNetworks 2019.07-2022.04 · Data Platform Senior Engineer

Led enterprise big-data platform build and operation work.
IBM Cloud Pak for Data migration for the CJ ENM big-data platform: portal analysis, CP4D API changes, Kubernetes project-creation API rebuild, MariaDB schema work, and IBM/InfraSoft/OpenShift collaboration.
Additional work: CJ CheilJedang BDP HR DB and Active Directory integration, used-car price-prediction crawler, CGV social-data channel expansion, CJ ENM visualization solution, and CGV AI Competitor operations.
Technologies: Python, Java, Linux, MongoDB, Solr, Redis, Impala, Hive, MariaDB, Spring, OpenShift, Kubernetes, IBM Cloud Pak for Data, RabbitMQ, Oozie, Hue.

G.Bike 2018.06-2019.06 · Software Engineer

Added long-term rental, bounty, payout, driver-license verification, rental/return, service-area, no-parking-zone, manager-app, and weekly release workflows.
Built Android/iOS apps, PHP backend APIs, MySQL tables, admin pages, and product UI scenarios.
Technologies: Swift, Objective-C, Java, Android, iOS, PHP, Firebase, MySQL, React Native, Google Maps.

Teamnova 2017.07-2018.03

Developed and operated the Popiece Android app, including exchange-rate fixes, crash/memory-leak analysis, and code review.
Led the Popiece iOS prototype, including travel-period calendar UI, calculator widget, country data flow, tab data transfer, and JIRA-based collaboration.
Technologies: RealmDB, Java, Swift, Today Widget, JTAppleCalendar, XLPagerTabStrip, Swifty JSON, Git, SVN.

DioTek 2013.05-2015.05 · Image Processing Developer

Researched and implemented OCR algorithms applicable to Chinese, Japanese, and Korean text.
Implemented handwriting/printed-text classification, notebook-line detection/removal and character restoration, color-boost correction, and dithering algorithm tuning.
Technologies: Python, C++, Android Java, SVN.

Digital Aria 2011.12-2013.04 · Research Engineer

Built version-based rendering automation tests and context-aware smart 3D GUI technology.
Managed a KOCCA national R&D project and coordinated vendors and partner institutions.
Worked on Kinect motion recognition, single-camera face/finger recognition, Android voice-recognition modules, and keyword extraction.
Technologies: C++ MFC, Android Java, Ruby, SVN, Jira, Confluence, Fisheye.

Side Project Details

claude-resume 2026.05

Interactive two-panel TUI that summarizes Claude Code history with LLM calls and resumes the chosen session.
Key decisions: no separate LLM API key, Textual-based modern TUI, JSONL timestamp sorting, recursive-session filtering, and temporary-file handoff.
Repository

claude-toolkit 2026.05-Present

Reusable Claude Code skills including LinkedIn draft generation and Adobe Firefly prompt conversion.
Uses a realistic "high-quality draft plus checklist" pattern where public APIs or posting permissions are constrained.
Repository and wiki

codex-resume 2026.05

Scans local Codex JSONL logs, extracts session metadata and previews, and resumes a selected session through Codex CLI.
Uses only Node.js built-in modules and provides `doctor`, `list`, `list --json`, `index`, and `resume` commands.
Repository

Early Android Side Projects 2016-2017

HotDealppom

Product recommendation app using user-interest signals from 11st, Coupang, and ppomppu data.
Technologies: Scrapy, Android, Volley, Google API, Firebase API, PHP, Nginx, Glide, MariaDB, Hadoop, Flume, KoNLPy.

BikeNavi

Android bicycle navigation project using Android, Volley, Google Maps, Tmap, Facebook API, Kakao service API, Glide, PHP, and MySQL.

Certifications, Language, Awards, and Research

AWS Certified Solutions Architect - Associate (2026.02-2029.02).
Amazon OpenSearch Service Subject Matter Expert (2023.05).
OCP 10g, Engineer Information Processing, Word Processor Level 2.
Languages: Korean native, English professional working level, Japanese elementary.
Award: encouragement prize for algorithm implementation, Korea Polytechnic University, 2008.11.20.

Academic and Research Activities

Research projects on cluttered-target tracking, multi-target tracking, and infrared clutter separation/tracking.
Publications on infrared-image segmentation, stereo-image feature matching, triangle-similarity-based matching, and image-resolution enhancement.
Patents and software registrations related to matching-pair classification, character recognition, stereo matching, and triangle-similarity-based feature matching.

Personal Statement

As an AWS Cloud Support Engineer II, I bring more than ten years of engineering experience across cloud analytics, data platforms, mobile applications, computer vision, backend APIs, and database design.

My strength is diagnosing complex distributed-system issues, improving data workflows, and turning repeated operational problems into reusable tools and workflows. I have worked with developers, infrastructure engineers, service teams, and business stakeholders to deliver scalable, reliable systems and practical customer outcomes.