CDC Resume Clarification

# CDC Resume Clarification

AI Summary

Purpose:

• Preserve the user's direct clarification of CDC ownership, rollout, delivery

semantics, collaboration, and technology-learning evidence for resume work.

Key points:

• Hyunwook directly designed and built the CDC system.
• Hyunwook completed the deployment-scenario review and handed the system to the

technical-support team.

• The technical-support team deploys and operates the system in approximately ten

customer environments. Hyunwook did not personally own customer deployment or day-to-day operation.

• Hyunwook receives issues found during operation, reproduces them, improves the

implementation, and provides technical support.

• Batch delivery is intentional. The product distributes binlog changes to

customer environments in batches, so real-time streaming was not the required operating model.

• Repository-backed production evidence clarifies the boundary: encrypted raw

binlog files are served by a Python/FastAPI download server; a customer-side Go Updater parses ROW events offline with a local go-mysql fork, handles MySQL 8.4 ZSTD Transaction_payload, and applies row changes through parameterized SQL.

• Existing operational notes record approximately hourly binlog-file batches.
• Leadership is expressed by connecting the dependency chain from data collection

to downstream analysis: analysis cannot begin until the required source data is identified and collected.

• Hyunwook's prior security-research background is relevant as evidence that he can

inspect unfamiliar open-source systems, understand their internal structure and constraints, and make implementation decisions quickly.

• Do not claim production Spark experience. Use the verified CDC tool-selection and

implementation history as evidence of transferable learning and technical judgment.

Relevant when:

• Writing or reviewing the Toss Payments Data Engineer resume.
• Preparing CDC, leadership, collaboration, or unfamiliar-technology interview answers.

Do not read full document unless:

• Exact wording for the CDC rollout or batch-versus-real-time decision is required.

Linked documents:

• ../../wiki/projects/bts.md
• ../../wiki/projects/2026-career-transition.md
• 2026-07-16-confluence-cdc-tool-research.md
• ../../../human/resume/toss-payments-data-engineer/resume-draft.md

Open Questions

• Exact team size and formal job title behind the Data Engineering Lead label.
• Exact production implementation boundary between collector, download server, and

customer updater remains to be reconciled with the repository evidence.

Details

User-confirmed statements from 2026-07-16:

• The CDC system was directly designed and implemented by Hyunwook.
• Hyunwook completed deployment-scenario review but did not personally deploy or

operate the system in customer environments.

• The technical-support team deploys and operates it in approximately ten customer

environments.

• Hyunwook receives operational issues from that team, reproduces and fixes them,

and supports the operating organization.

• It is a batch-oriented CDC design because the existing customer-delivery model

distributes binlog changes in batches; real-time streaming was not the target.

• Collection precedes analysis in the operating workflow, and Hyunwook connects

those stages so analysis receives the required source data.

• Security research is the starting background. Fast comprehension of unfamiliar

open-source tools, architecture, and constraints is a durable strength.