𝗦𝗵𝗼𝗽𝗶𝗳𝘆 𝗵𝗶𝘁 𝟰𝟴𝟵𝗠 𝗿𝗲𝗾𝘂𝗲𝘀𝘁𝘀/𝗺𝗶𝗻 𝗱𝘂𝗿𝗶𝗻𝗴 𝗕𝗹𝗮𝗰𝗸 𝗙𝗿𝗶𝗱𝗮𝘆 𝗼𝗻 𝗮 𝗺𝗼𝗻𝗼𝗹𝗶𝘁𝗵

Many engineers assume this scale forces microservices.

Shopify keeps proving a different playbook: 𝗼𝗻𝗲 𝗱𝗲𝗽𝗹𝗼𝘆, 𝘀𝘁𝗿𝗼𝗻𝗴 𝗯𝗼𝘂𝗻𝗱𝗮𝗿𝗶𝗲𝘀, 𝗵𝘂𝗴𝗲 𝗶𝗻𝗳𝗿𝗮

𝗕𝗹𝗮𝗰𝗸 𝗙𝗿𝗶𝗱𝗮𝘆 𝟮𝟬𝟮𝟱, 𝗯𝘆 𝘁𝗵𝗲 𝗻𝘂𝗺𝗯𝗲𝗿𝘀:

🔹 $14.6B merchant sales (+27% YoY)

🔹 Edge: 489M requests/min peak (312M avg across BFCM)

🔹 App servers: 117M requests/min peak (+40% YoY)

🔹 API: 31.8M requests/min peak

🔹 Observability: 11TB logs/min at peak

🔹 Kubernetes: 3.18M CPU cores at peak

🔹 DB (MySQL 8): 53.8M queries/sec, plus 4.28B row ops/sec at peak

🔹 Writes: 2M writes/sec at peak

🔹 CDN: 183M requests/min, 97.8% served from cache

🔹 Async: 23.2M jobs/min at peak

🔹 Streaming: Kafka + Flink, 150 MB/sec processed; analytics latency improved 103×

Why a modular monolith works here:

➡️ One codebase, one release train, one primary runtime.

➡️ Clear domain components (orders, inventory, billing…) with enforced interfaces.

➡️ Rails Engines + tooling (Packwerk) to keep boundaries real, not “handshake agreements”.

👉 𝗧𝗮𝗸𝗲𝗮𝘄𝗮𝘆: scaling often fails from 𝗯𝗼𝘂𝗻𝗱𝗮𝗿𝘆 𝗱𝗲𝗯𝘁, not “monolith vs microservices.”

Pick the simplest architecture that lets teams ship fast, then enforce boundaries hard.