Day 3 Data Structure Codex AI Architect

Data design tasks based on Codex Client Workspace

Differences in data structure understanding, terminology fragmentation, and change impact propagation issues that startups face during the MVP development stage
This is a practical AI collaboration task board that automatically analyzes and resolves using Codex.

Day 3 Startup MVP Tasks

From aligning data structures to standardizing terminology and sharing the impact of changes — experience core workflows with Codex as your data design partner.

TASK 1
Task 1

Task 1. Practice resolving gaps in data structure understanding

Task 01: Alignment of data structure between planning and development (Data Structure Alignment)

By deriving key entities and relationships (Mermaid ERD) from planning meeting minutes written in natural language, the gap in data model understanding between planners and developers is resolved with AI.

target numberCompletion of ERD schema and data structure definition
core toolsCodex Client Workspace
scope of practiceData Structure Alignment
Step 1 📂 Prepare meeting minutes file (day3_meeting_notes.md) and upload Codex
Step 2 🔍 Request Codex to derive entities and create Mermaid ERD
ERD Entity Mapping Data Alignment
expected output erd-schema.md (Data Specification and ERD)
Task 1 Entry to the lab
TASK 2
Task 2

Task 2. Terminology standardization practice

Task 02: Resolving domain-specific terminology fragmentation (Terminology Standardization)

It analyzes the mixed use of fragmented terms such as plan (member), API specification (User), screen (customer), and DB (Member) and automatically builds an integrated standard terminology dictionary.

target numberCompletion of standard glossary
core toolsCodex Client Workspace
scope of practiceTerminology Standardization
Step 1 📁 Write and prepare fragmented-terms.md
Step 2 📋 Derive standard terminology dictionary and variable name mapping with Codex
Glossary Terminology Domain Standard
expected output project-glossary.md (Standard Glossary)
Task 2 Entry to the lab
TASK 3
Task 3

Task 3. Practice sharing change impact

Task 03: Analysis of the scope of impact when changing DB schema (Change Impact Analysis)

When the DB physical schema or core business logic is changed, the API specifications and UI screens affected are automatically analyzed with Codex and a report is created for team sharing.

target numberCompletion of change impact analysis report
core toolsCodex Client Workspace
scope of practiceChange Impact Analysis
Step 1 📂 Prepare a schema change request (schema-change-request.md)
Step 2 🔄 Complete analysis of API/screen influence range and generation of shared report with Codex
Schema Change Impact Analysis API/UI Sync
expected output change-impact-report.md (Change Impact Analysis)
Task 3 Entry to the lab
🚀 In-depth Mission — Data Design Master Course
MISSION 1
Mission 1

Mission 1. Design decision recording practice

Mission 01: Automatic creation of Design Decision Log (Record Why)

By writing the database normalization and architecture decision background into a Design Decision Log standardized in Codex, duplicate discussions and design mistakes are prevented when new team members join.

target numberComplete design decision record document (DDL)
core toolsCodex Client Workspace
scope of practiceDesign Decision Log & Knowledge Mgmt
Step 1 📂 Preparation of technical design meeting conversation transcript (tech-design-meeting.md)
Step 2 🔍 Request Codex to standardize resolution items, background reasons, and alternative review
Decision Log Architecture Knowledge Mgmt
expected output design-decision-log.md (Decision record document)
Mission 1 Lab Entry
MISSION 2
Mission 2

Mission 2. Exception scenario discovery practice

Mission 02: Derive all concurrency and integrity edge cases (Edge Case Discovery)

Edge cases such as concurrency errors, referential integrity collapse, and hard delete failures that may occur in the defined DB schema and foreign key reference structure are discovered in advance using Codex.

target numberCompletion of exception scenario report and response plan
core toolsCodex Client Workspace
scope of practiceEdge Case Discovery & Integrity Guard
Step 1 📂 Preparation of DB physical schema definition (database-schema.md)
Step 2 🛡️ Derive all concurrency and integrity exception cases and establish countermeasures with Codex
Edge Cases Concurrency Soft Delete
expected output edge-case-analysis.md (Exception scenario report)
Mission 2 Lab Entry