Add high level infrastructure doc

README.md

@@ -1,3 +1,26 @@
 # OONI Devops
 
-This documentation contains information
+At a glance below is the overall architecture of OONI Infrastructure across our various locations:
+
+```mermaid
+flowchart TB
+    apiorg([api.ooni.org])-->alb
+    apiio([api.ooni.io])-->backend
+    ecs[Backend API ECS]<-->ch[(Clickhouse Cluster)]
+    subgraph Hetzner
+        backend[OONI Backend Monolith]<-->ch
+        monitoring[Monitoring host]
+        pipeline[Pipeline v5]
+    end
+    subgraph AWS
+    alb[API Load Balancer]<-->ecs
+    alb-->backend
+    ecs<-->s3[(OONI S3 Buckets)]
+    s3<-->backend
+    end
+    subgraph Digital Ocean
+        th[Web Connectivity Test helper]<-->alb
+    end
+```
+
+For more details [Infrastructure docs](https://docs.ooni.org/devops/infrastructure/)