Three-tier app in a VPC architecture

The same three-tier shape drawn the way AWS actually organises it: edge in a public subnet, app and data in a private one, and the pieces that live outside the VPC outside the box.

AWSvpcsubnetalbfargate
VPCprod-vpc · 10.0.0.0/16SUBNETpublic · 10.0.1.0/24SUBNETprivate · 10.0.2.0/24Route 531 zone + queriesCloudFront500 GB egress · insidethe 1 TB free tierLoad balancer (ALB)1 ALB + light LCUusageNAT gateway1 gateway + 100 GBApp service ×33 × 1 vCPU · 2 GBPrimary databasedb.t4g.large ·multi-AZ · 100 GBElastiCache Rediscache.t4g.smallUser uploads100 GB standardCloudWatch logs30 GB ingested
12 nodes — 9 infrastructure and 3 agent, on one graph. Drawn by the same layout the product uses.
What is in it

Every resource, and what it costs.

Projections from August 2026 list prices for always-on resources. Connect an account and these become the figures your provider actually bills.

Resources in the Three-tier app in a VPC template with projected monthly cost.
NodeTypeWhat it isProjected
Route 53Network1 zone + queries$1.00/mo
CloudFrontCDN500 GB egress · inside the 1 TB free tierno direct cost
Load balancer (ALB)Network1 ALB + light LCU usage$23/mo
NAT gatewayNetwork1 gateway + 100 GB$37/mo
App service ×3Compute3 × 1 vCPU · 2 GB$108/mo
Primary databaseDatabasedb.t4g.large · multi-AZ · 100 GB$215/mo
ElastiCache RedisDatabasecache.t4g.small$25/mo
User uploadsStorage100 GB standard$3.00/mo
CloudWatch logsExternal30 GB ingested$18/mo
prod-vpc · 10.0.0.0/16group
public · 10.0.1.0/24group
private · 10.0.2.0/24group

Agent steps are priced from provider-reported token usage once the agent runs, not estimated. Guardrails cost nothing and are the reason a runaway agent cannot. One row shows from because those services bill by usage, so the total is a scenario at the stated volumes, not a quote.

Open Three-tier app in a VPC on the canvas.

It loads as an editable graph. Connect an account or instrument an agent and the projected figures above become measured ones.