--- title: Designing a Credit-Management Microservice for Partner... description: Mercari's Merpay team shares how they extracted credit management into a dedicated microservice to support partner invoice payment across multiple products.... canonical: https://daily.dev/posts/designing-a-credit-management-microservice-for-partner-invoice-payment-q4w0n1bqa twitter:card: summary_large_image twitter:site: @dailydotdev og:type: website og:site_name: daily.dev og:title: Designing a Credit-Management Microservice for Partner Invoice Payment | daily.dev og:description: Mercari's Merpay team shares how they extracted credit management into a dedicated microservice to support partner invoice payment across multiple products.... og:url: https://daily.dev/posts/designing-a-credit-management-microservice-for-partner-invoice-payment-q4w0n1bqa og:image: https://api.daily.dev/og/posts/q4w0n1BqA.png og:image:alt: Designing a Credit-Management Microservice for Partner Invoice Payment og:image:width: 1200 og:image:height: 630 og:locale: en --- [Mercari Engineering](https://daily.dev/sources/mercari) [Read post](https://api.daily.dev/r/q4w0n1BqA) # [Designing a Credit-Management Microservice for Partner Invoice Payment](https://api.daily.dev/r/q4w0n1BqA "Go to post") Mercari's Merpay team shares how they extracted credit management into a dedicated microservice to support partner invoice payment across multiple products. The post covers four key design decisions: (1) consolidating all credit-domain logic into one service with clear ownership boundaries, (2) decoupling credit granularity from invoicing granularity using aggregation axes in a shared Debt Service, (3) allowing partners to have multiple configurable credit lines under a single hard credit limit, and (4) modeling credit usage as stateful transactions with Authorize/Capture/Cancel phases and configurable reservation policies. The architecture enables new products to plug into the full payment-to-invoicing lifecycle by simply creating a credit line and invoice account, without modifying platform services. [#microservices](/tags/microservices "Check all #microservices posts")[#fintech](/tags/fintech "Check all #fintech posts")[#distributed-systems](/tags/distributed-systems "Check all #distributed-systems posts")[#domain-driven-design](/tags/domain-driven-design "Check all #domain-driven-design posts") Aug 06•9m read time•From [engineering.mercari.com](https://api.daily.dev/r/q4w0n1BqA "engineering.mercari.com") [](https://api.daily.dev/r/q4w0n1BqA "Go to post") Table of contents [Introduction](https://api.daily.dev/r/q4w0n1BqA "Introduction")[Background: How partner invoicing worked previously](https://api.daily.dev/r/q4w0n1BqA "Background: How partner invoicing worked previously")[Problem: Why credit management became necessary](https://api.daily.dev/r/q4w0n1BqA "Problem: Why credit management became necessary")[Design: Four key design points](https://api.daily.dev/r/q4w0n1BqA "Design: Four key design points")[End-to-end view: making the entire platform work as one system](https://api.daily.dev/r/q4w0n1BqA "End-to-end view: making the entire platform work as one system")[Conclusion](https://api.daily.dev/r/q4w0n1BqA "Conclusion") 246 Impressions Comment Bookmark Copy Share your thoughtsPost [](https://daily.dev/sources/mercari) [Mercari Engineering](https://daily.dev/sources/mercari "https://daily.dev/sources/mercari") Mercari's platform is a resource for developers and technology enthusiasts, offering insights into e... 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