Autromaster Mobile (AMM): AWS dynamic cost model

This page shows what drives the monthly AWS bill for AMM. Read the diagram left to right:

Fleet → systems, gateways and the heartbeat interval decide how many messages are sent per month.
Messages → the message volume sets the cost of IoT Core, Kinesis, Lambda and SQS.
Platform → the other services are mostly fixed charges for what is running (NAT gateways, servers, databases, logging).
Total → all services plus 25 % tax, per month and for 12 months.

Colours: light green = inputs you can change dark green = follows message volume grey-green = platform

Try it: move any slider below the diagram to see how the monthly cost changes.

Systems and heartbeat settings set the monthly message volume; the four message-driven services price that volume, the platform services are mostly hourly charges for what exists, and tax adds 25 % on top. Values are the workbook at its current inputs.

Fleet

Systems in the app database

Drivers!B5 · 1,410 in Neo4j

Share of systems active

Drivers!B6 · 154 never connected, 149 silent

Share of active that are AutroSafe

Drivers!B8

Heartbeat interval (seconds)

Drivers!B15 · today 20 s

AutroSafe systems in a degraded state

Drivers!B19

Rules matched per NDATA message

IoT!I5 · 2 = duplicate rule present

Largest Lambda function, avg duration (ms)

Lambda!I5 · statusPropagator (40 % of Lambda)

Shards on the two empty Kinesis streams

Kinesis!B7, B8

Platform inventory

NAT gateways

Platform · $37.44 each · 9 until 23 Sep, 4 now (September average 7.8)

Interface VPC endpoints

Platform · 3 AZs × $8.64 · 13 until 23 Sep, 3 now (September average shown)

EC2 t3.medium instances

Platform · $34.56 each per month

Lambda Insights logging

Platform · largest CloudWatch line · 0 = off

VPC flow-log copy to S3

Platform · 0 = stopped; GuardDuty still reads flow logs

Logs Insights scanned per month (TB)

Platform · people and dashboards

Cost by service at these inputs

Service	Behaviour	September 2026 (30-day)	Model month	Change	× 12

EC2-Other and VPC sit below September on purpose: five NAT gateways and ten interface endpoints were deleted on 23 September, so the model shows the run-rate entering October.

The steps, with the current numbers

1 · Systems to gateways

2 · Gateways and systems to messages

3 · IoT Core messages

messages × $1.20/M + rules × $0.18/M + actions × $0.18/M + connection minutes + registry

4 · Kinesis messages

shards × 720 h × $0.018 + rule actions × $0.0175/M

5 · Lambda messages

invocations = per-1M-messages × total GB-seconds = invocations × ms/1000 × MB/1024 cost = GB-seconds × price(arch) + invocations × $0.20/M

6 · SQS messages

requests = (sent + received + deleted) per 1M messages × total + empty receives cost = requests × $0.40/M (FIFO $0.50/M)

7 · Platform inventory

fixed line: quantity × unit price (NAT-hours, ENI-hours, instance-hours, GB-months, key-months …) message-driven line: quantity per 1M messages × total messages × unit price