Summary
Engineering leader with 8 + years building cloud‑native payment and marketplace platforms at global scale. Proven record of cutting cloud spend by $1.2 M / yr, delivering zero‑downtime MySQL migrations, and tripling developer release velocity while hardening K8s reliability to 99.99 %.
Cloud & Platforms, Databases, Observability & SRE, Programming
Experience
Engineering Manager, SRE
Apr 2024 - Present
Mercari US•Palo Alto, CA
1 yr 2 mos
- Managed a cross‑geo SRE team of 4 engineers across US & JP time‑zones
- Led FinOps program: rightsized Cloud SQL shards, migrated CDN/WAF to Cloudflare, and removed idle AWS resources, cutting > $30 K / mo and avoiding $1.2 M / yr spend
- Implemented data‑footprint reduction program (‑50 % on 25 TB main shard) to accelerate backups and lower storage costs
- Executed zero‑downtime primary switch‑over to Rocky Linux MySQL and enabled writeset replication, unlocking MySQL 8 rollout
- Instituted SLO‑driven on‑call; reduced flaky alerts by 40 % and cut MTTR by 20 %
- Introduced 50 / 30 / 20 ownership matrix and facilitated weekly SRE‑EM cadences, boosting accountability and delivery
Software Engineer, Site Reliability Engineering (SRE)
Jan 2022 - Mar 2024
Mercari US•Palo Alto, CA
2 yrs 2 mos
- Operated 100+ node GKE clusters powering 200+ microservices, and upgraded Istio service mesh and two 200-node clusters with zero downtime via automated canary rollout scripts.
- Rolled out Mimir + Loki stack, reducing MTTR from 45 min to 12 min.
- Developed and delivered MySQL shard archival tooling and schema-change automation.
- Reduced GKE compute spend by 18% QoQ through workload right-sizing and maximizing Committed-Use Discounts.
- Authored 35+ internal guides on cost optimization and reliability, boosting cross-team knowledge sharing and onboarding speed.
Software Engineer, Merpay Payment Platform
Jan 2020 - Dec 2021
Mercari Japan•Tokyo, Japan
1 yr 11 mos
- Owned the payment microservice core state-machine, enabling all value exchanges across the Mercari group.
- Led platform reliability and security initiatives, including chaos engineering and compliance, measurably improving service robustness.
- Delivered peer-to-peer money transfer from design to production and migrated a high-traffic API partner with zero downtime.
- Spearheaded Pub/Sub proxy migration across four services, cutting cross-org request latency by 35% and eliminating a bespoke broker.
- Designed and shipped a transaction-management SDK (Saga/TCC patterns) adopted by 10+ payment microservices, and implemented a gRPC tracing interceptor that reduced client-visible Spanner errors by 80%.
Senior Software Engineer
Feb 2019 - Dec 2019
Taskworld•Tokyo, Japan
10 mos
- Designed and shipped greenfield microservices in Go for Taskworld 2.0.
- Prototyped an Elasticsearch + Cassandra stack to replace MongoDB, improving scalability and search capabilities.
- Collaborated with backend, frontend, and design teams to rapidly iterate on new user workflows.
Software Engineering Team Lead
Aug 2018 - Jan 2019
Taskworld•Bangkok, Thailand
5 mos
- Managed a cross-functional team of 4 engineers across Bangkok and Tokyo, driving collaboration and delivery.
- Owned the Go-based payment subsystem supporting global subscriptions.
- Delivered full-stack features using React, Node.js, TypeScript, MongoDB, RabbitMQ, Elasticsearch, Redis, and Kubernetes.
Software Engineer
Sep 2017 - Jul 2018
Taskworld•Bangkok Metropolitan Area, Thailand
10 mos
- Built Go payment micro‑service powering subscription and billing flows
- Created Taskworld's first public REST API with developer documentation and examples
- Maintained on‑premise enterprise deployment and optimized backend performance via micro‑tuning
Software Engineer
Aug 2016 - Jul 2017
Solomon Strategic Consulting•Seoul, South Korea
11 mos
- Delivered an anticorruption law iOS app for Yulchon, a leading Korean law firm, enhancing legal compliance and accessibility for clients.
- Created a reusable Android WebView container, streamlining mobile app development and ensuring consistent user experience across numerous production apps.
- Led the redesign and modernization of eyulchon.com, improving site usability and visual appeal for a professional audience.
- Developed an NLP server and React-Redux chatbot (Python, NLTK, KoNLPy, spaCy, Flask), enabling automated client interactions and seamless integration with legacy ASP.NET systems.
Education
Yonsei University
Mar 2015 - Feb 2017
Finance Master's degree
1 yr 11 mos
Chonnam National University
Mar 2014 - Feb 2015
Korean Language Program Language Program
11 mos
National University of Mongolia
Sep 2010 - Jun 2014
Economics Bachelor's degree
3 yrs 9 mos
Languages
- EnglishNative or Bilingual
- MongolianNative or Bilingual
- GermanLimited Working
- KoreanLimited Working
- JapaneseElementary
Certifications
Skills
Cloud & Platforms
GCP, AWS, Terraform, Kubernetes, Istio, Cloudflare
Databases
MySQL, Spanner, MongoDB
Observability & SRE
Prometheus, Grafana, Loki, Mimir, SLOs, Incident Response, FinOps
Programming
Go, TypeScript, React
Honors & Awards
- KGSP 2014 (Korean Government Scholarship Program)
- Dean's List – Spring 2016