Hello! This is yasu_shiwaku from the Mercari Engineering Office.
We have our annual Advent Calendar blogathon event in December every year and we’ll be hosting it again this year!
We have both Mercari and Merpay/Mercoin Advent Calendar at the same time, so please check out Merpay/Mercoin side as well.
▶Merpay & Mercoin Advent Calendar 2025
counts down to Christmas".
We’ll be sharing our knowledge of the technologies used by our engineers at Mercari group. We hope this Advent Calendar will help you to enjoy the days leading up to Christmas.
Advent Calendars 2024
Publishing schedule
This is a collection of links to each article. I recommend bookmarking this page for the prompt update, and it will be very useful if you want to check it out at a later date.
| Date | Theme / Title | Author |
|---|---|---|
| 12/1 | Websocket XSS vulnerability discovery: My security journey at Mercari | @philolo1 |
| 12/2 | LLM Key Server: Providing Secure and Convenient Access to Internal LLM APIs | @Hiroki Akamatsu |
| 12/3 | Shops Monorepo Five Years Later: A Tale of Bazel and Cursor | @Jazz |
| 12/4 | Enhancing DX through Mercari’s Unified Platform Interface | @whygee |
| 12/5 | メルカリ ハロ Web フロントエンドの1年間の改善と学び | @mattsuu |
| 12/6 | Engineering The Semantic Layer: Principles for Data at Scale | @sathiya |
| 12/7 | QAエンジニアがAIで日々の課題を解決した話 | @yuga |
| 12/8 | Navigating Change: Learning to Reinvent in an Unstable World | @Antony Chane-Hive |
| 12/9 | Search Results Quality Monitoring with LLMs | @otter |
| 12/10 | LiveContactToolにおける機微情報の取り扱い~CloudDLPを使ったマスキング | @sters |
| 12/11 | OpenID Connect Core 1.0 の Claims パラメーターの利用 | @kgoro |
| 12/12 | Adsシステムの急成長を支える技術：信頼性と収益性を取り戻した「PJ-MARP」の全貌 | @tokku |
| 12/13 | メルカリが、AI時代にナレッジマネジメントに投資したわけ メルカリのナレッジマネジメント戦略 | @t-hiroi |
| 12/14 | メルカリAdsが広告を届けるまでの話 | @yanap |
| 12/15 | TiDB Resource Groupでワークロードを制御する | @ogataka50 |
| 12/16 | The Cost of Speed: A Battle against Cost, Debt, and Diverging Systems | @Sneha |
| 12/17 | Building a Learning Culture with DevDojo | @mariz |
| 12/18 | [TBD] Kubernetes Packet Capture | @mshibuya |
| 12/19 | AI-Native開発を加速する AWS Kiro の導入と、Okta を活用したアカウント管理の自動化 | @amenbo & @siroken3 |
| 12/19 | [TBD] DCR の話 | @task |
| 12/20 | PR‑Driven Changes, CI/CD‑Automated Apply — Building Jamf Pro IaC + GitOps with Terraform | @yu |
| 12/21 | [TBD] Non-AI Tasks in the AI Task Force | @akkie |
| 12/22 | What It Takes to Trust a Token: Tales of OIDC & OAuth Security | @Kahla |
| 12/23 | [TBD] | @Sneha & @Yu |
| 12/24 | メルカリのNotion Architecture ver.1 の話 | @kiko & aisaka |
| 12/25 | TBD | @kimuras |
Please bookmark this article and check it out when you want to read it so you can be aware of article publication notifications!
We’re looking forward to bringing you some interesting technology stories in the last month of 2025! I hope you’re looking forward to the Advent Calendar!
