You tapped View Product.

Understand it one step at a time

The short runs these in order in about 50 seconds. Here they are written out — pick any step to jump the short straight to it.

1. 1

   You tap View Product

   One tap on a phone. Everything after it happens in Azure, and it has under a second.

   msdevbuild.shop · GET /products/123

2. 2

   First stop is the edge, not your app

   Front Door and CDN sit in front of everything. The request lands on a POP near the phone.

   azure front door · edge POP · nearest region

3. 3

   Cache hit: your app never wakes up

   The edge already holds this response. It answers in 18 ms and your API never sees the request.

   edge · CACHE HIT · 18 ms · origin untouched

4. 4

   Cache miss: keep going

   Nothing cached, or the response says not to cache it. Front Door forwards to the origin.

   edge · CACHE MISS · forwarding to origin

5. 5

   The API asks Redis before SQL

   App Service takes the request and looks in Azure Cache for Redis first. Always first.

   app service · GET product:123 · cache-aside

6. 6

   Redis hit: 2 ms, no database

   The product JSON is already in memory. Price, stock, done — and SQL is never queried.

   redis · HIT · product:123 · 2 ms

7. 7

   Redis miss: now you pay for the query

   Nothing in memory. The API has to go to the one place that actually owns the data.

   redis · MISS · falling through to SQL

8. 8

   Azure SQL is the source of truth

   One indexed lookup on ProductId 123. Price $99, stock 24 — correct, and slower than memory.

   azure sql · SELECT · 85 ms round trip

9. 9

   Write it back with a TTL

   The API puts the row into Redis before it answers. The next viewer never reaches SQL.

   redis · SET product:123 · TTL 60s

10. 10

    The image never touches your API

    Product photos live in Blob Storage and come off the edge. A completely separate path.

    blob storage · products/123/hero.webp · 240 KB

11. 11

    One tap, five services

    Edge, API, cache, database, storage. Each one exists to stop the next one being asked.

    msdevbuild.shop · one request · five hops

12. 12

    One click. One fast experience

    The fast path is the normal path. SQL is the exception — and that is the entire design.

    microsoft azure · product 123 · served