Software Engineer in Warm Storage team, Meta

Vancouver, BC, Canada

Software Development Engineer in Automated Profitability Management team, Amazon

Vancouver, BC, Canada

• Led integration of the On-demand Vendor Negotiation system into an organization-wide vendor data analysis platform. Collaborated with counterpart teams to clarify business/technical requirements and develop the features, designed seamless UX/UI and backend APIs over the products, and managed the project launch schedule. Resolved technical challenges such as reduced latency with ElasticSearch to fulfill SLAs and used multi-threading to optimize workflow.

• Designed and implemented the multiple components across the team – user permission system with simple/scalable onboarding mechanism, notifier for negotiation status updates, tracking system for customer agreements to prove actions, dynamic term selection for negotiators to choose the order of negotiating terms with validating correctness, etc.

• Led design and development of bulk upload system for vendor relationship management service using S3, SQS, and lambda, allowing users to upload information from vendors at once, operated by parallelized lambda functions for speed up.

Software Engineer in Cloud Platform Part, Kakao Corporation

Seongnam, Republic of Korea

• Designed and implemented the automatic data migration system that transferred old/unmodified data to cold storage reducing size by 33% with an optimized scanning strategy in hundreds of petabyte scale distributed file system.

• Designed a caching file system with a regex cache invalidation strategy, reducing the fluctuation of IO performance by 80%, and optimizing lock logic with a bloom filter to prevent slowdown from overloaded contents, increasing speeds by 300%.

• Developed and operated a large-scale cache service (~20k TPS per host, 500+ hosts) with 2 layered distributed clusters, cache invalidation worker servers, the serverless service (Openwhisk) for in-house developers.

• Developed a fast memory cache plugin for high traffic – mid volume services, allowing 400% of traffic without delay.

• Managed a key-value storage component (HBase) for file metadata that recovers lost storage items, gathered/analyzed the statistics of storage usage/traffic by services, and reformed meta structure to achieve better consistency.

Yunho Kim, Taejin Kim, Moonzoo Kim, et al., Effective Integer Promotion Bug Detection Technique for Embedded Software, Journal of KIISE: Software and Applications, Vol. 43, Num 6, Jun 2016

Taejin Kim, Moonzoo Kim, et al., Detecting Integer Promotion Bugs with Embedded Software using Static Analysis Technique, Korea Computer Congress, Dec 17-19, 2015 (Best Paper Award)