TECH PLAY will host an online event titled “AI’s ‘Right Answer’ Isn’t Always the Right Answer for Your System — Architectural Decisions Made by Tech Leads During the PayPay Card Credit Screening System Modernization —” on Wednesday, August 26, 2026.
As AI becomes increasingly integrated into software development, engineers are finding more opportunities to leverage AI-generated outputs across various stages of system design and implementation.
At PayPay Card, we are also actively incorporating AI into our development processes as we continue to bring the development of our Credit Screening and Collections systems in-house.
However, building the right system requires more than simply adopting the answers suggested by AI. Engineers still play a critical role in making final design decisions by considering factors beyond immediate requirements, including future scalability, maintainability, and business requirements that have yet to be fully articulated.
So, how far should we rely on AI-generated proposals, and where should engineers make their own decisions?
In this event, Tech Leads responsible for the in-house development of PayPay Card’s Credit Screening and Collections systems will share real-world examples of the architectural decisions and challenges they have encountered while working alongside AI.
Through insights from our actual development environment, we will explore the evolving role of Tech Leads in the AI era and how engineers can make architectural decisions that take the long-term future of a system into account.
If you’re interested in AI-assisted software development, system architecture, or the evolving role of Tech Leads in the AI era, we invite you to join us.
August 26, 2026 (Wed) [PayPay Card Growth Tech! vol.2] (This event will be held in Japanese.)
Event Overview
Title：AI’s “Right Answer” Isn’t Always the Right Answer for Your System — Architectural Decisions Made by Tech Leads During the PayPay Card Credit Screening System Modernization —
Date & Time：August 26, 2026 (Wed), 19:00-20:20
Venue：Online
Host：TECH PLAY
- Time
Content
- 19:00-19:05
Opening Remarks/ HOST（TECH PLAY）
- 19:05-19:20
AI × Development Case Study #1: Architectural Decisions Made by a Tech Lead “Why Business Understanding Defines the Value of a Tech Lead in the AI Era” / Michiaki Saga
- 19:20-19:35
AI × Development Case Study #2: Architectural Decisions Made by a Tech Lead “Knowing When Not to Solve Everything Within the System — and Making Those Decisions Reproducible with ADRs” / Jin Okamoto
- 19:35-19:45
What Should Tech Leads Be Responsible for in the AI Era? / Masashi Ono
- 19:45-19:55
Inside PayPay Card’s Credit Screening & Collections Development Organization — Behind the Scenes of an AI-Driven Engineering Organization —/ Tatsuya Hashimura
- 19:55-20:15
Q&A Session
- 20:15-20:20
Closing Remarks/ Host（TECH PLAY）
About the Speakers
Tatsuya Hashimura
Head of Credit & Receivables Development Department,Systems Division, Technology Unit, PayPay Card
He began his engineering career in 2011. Before joining PayPay Card, he worked at a product company, leading the development of business systems, e-commerce platforms, and various software projects. He joined PayPay Card Corporation in 2024 and led initiatives including the modernization of the collections management system, telephony platform renewal, and AI proof-of-concept projects for debt collection. Since 2026, he has served as General Manager of the Credit & Receivables Development Department, overseeing engineering organizations across both the Credit Screening and Collections domains.
Masashi Ono
Tech Lead, Credit & Receivables Development Department, System Division, Technology Unit, PayPay Card
He joined LINE Corporation (now LY Corporation) in 2014, where he worked on system development for the News business. He was seconded to PayPay Card in 2023 and officially joined PayPay Card Corporation in 2025. He currently serves as a Tech Lead, leading architectural design and technical decision-making for systems in the Credit Screening and Collections domain.
Michiaki Saga
Tech Lead,Credit & Receivables Development Department, System Division, Technology UnitTechnology Management Group, PayPay Card
He began his engineering career in 2015 and joined LINE Corporation (now LY Corporation) in 2021. He was seconded to PayPay Card in 2023 and officially joined PayPay Card Corporation in 2025. He currently serves as a Tech Lead for the Credit Screening and Ongoing Credit Management systems while leading the organization's AI-driven development initiatives.
Jin Okamoto
Tech Lead, Credit Development Group, Credit & Receivables Development Department, Systems Division, Technology Unit, PayPay Card
He began his engineering career in 2015 and joined PayPay Card Corporation in 2024. As a Tech Lead, he has led the in-house redevelopment of the credit screening system, transforming its monolithic architecture into cloud-native microservices while driving modernization of the overall system architecture.
Important Information for Participants
- Participation is free of charge.
- As this is an online event, you can join from anywhere.
- You are welcome to leave the session at any time.
- Questions for the speakers can be submitted via chat during the event.
- This event will be conducted in Japanese.
For more details and registration, please visit the event page below.
August 26, 2026 (Wed) [PayPay Card Growth Tech! vol.2](This event will be held in Japanese.)