This event will be held primarily in Japanese.
On Wednesday, December 17, 2025, TECH PLAY will host an online event titled “Break Through Constraints: Changing Common Sense with an Engineering-Driven Approach — Behind the Scenes of PayPay Card Development Achieving Both Speed and Reliability.”
Developing systems at a credit card company is often seen as a “highly constrained domain”, where rigorous security standards and complex business requirements intertwine—making it seem impossible to prioritize speed.
However, PayPay Card has tackled these constraints head-on, designing a system that balances speed with reliability. We have challenged the conventional wisdom of the financial industry by:
- Revamping infrastructure where batch processing was the norm into real-time processing that reflects transactions the instant they occur.
- Migrating an on-premise-based infrastructure to AWS while satisfying strict security requirements.
- Bringing core system development in-house to shift toward a structure where engineers lead improvement cycles and quality assurance.
In this event, PayPay Card engineers will unravel exactly how they made decisions and implemented technologies within this constrained environment, based on actual projects.
- How we deciphered specific constraints and decided where to go on the offensive (addressing batch-reliance, security, and cloud adoption).
- How we segmented increasingly complex payment processes to establish a distributed architecture (design decisions using DDD, and the impact on business domains and organization).
- The extent of discretion engineers hold in an in-house development environment and how decisions are made (processes, structure, and role division).
We will share the judgment criteria and design thinking behind “how to arrive at a design that balances speed and reliability, even amidst constraints,” accompanied by the realities of the field. We invite you to experience our engineering-driven culture that pushes past fixed ideas, honing technical skills precisely because of the constraints, and encouraging bold challenges.
December 17, 2025 (Wed) [PayPay Card Growth Tech! vol.1]
Event Overview
Title: Break Through Constraints: Changing Common Sense with an Engineering-Driven Approach — Behind the Scenes of PayPay Card Development Achieving Both Speed and Reliability
Date & Time: December 17, 2025 (Wed), 19:00~20:20
Venue: Online
Host: TECH PLAY
- 19:00〜19:05
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Opening
- 19:05～19:20
-
PayPay Card’s Product Organization Opening Up the “Future of Payments”
Kenta Mikami
I will introduce the culture of PayPay Card’s product development organization, our current business phase, past initiatives for product improvement, and our vision for the future.
- 19:20〜19:40
-
Behind the Scenes of Realizing the “Real-time Payment Information Check Function”
Hiroya Sato
I will discuss the development process that led to providing a unique PayPay Card payment experience. This involves overcoming the complexities of credit card-specific processing and data pattern challenges without interrupting the payment notification function used by many customers.
- 19:40～20:00
-
Rethinking Payment Processing: Applying Domain-Driven Design to Build a Distributed Architecture
Abhishek Jain
Breaking a monolith into micro-services is only part of the story. True transformation requires rethinking how we design systems, model business domains, and collaborate across teams. In this session, I will explore how the Payment Processing team is reimagining its architecture using Domain-Driven Design (DDD) principles. Through the lens of credit card payment processing, I will discuss how aligning architecture with business domains can reshape not only our technical design but also how products and stakeholders approach change.
- 20:00～20:15
-
Ｑ&Ａ
- 20:15〜20:20
-
Closing
- This is a free seminar.
- Participants can join from anywhere as it is online.
- Participants are free to leave the seminar whenever they choose.
- Questions to the presenters will be accepted via chat during the seminar.
- This event will be held primarily in Japanese.
Please see the event page below for more details or to apply.
December 17, 2025 (Wed) [PayPay Card Growth Tech! vol.1]