What-If Simulator

An interactive scenario engine that re-runs your last 90 days of cloud usage against any hypothesis: a new Savings Plan, a 30% traffic spike, a region migration, or a switch from on-demand to Spot — all on real data.

90 days of real usage
Stackable scenarios
Confidence bands

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lumicost.com — what-if-simulator

By the numbers

What-If Simulatorin 4 numbers

DOWNSIZE · RESERVED_INSTANCE · SCHEDULE_STOP · DELETE · STORAGE_LIFECYCLE

scenario types

simulation is fully read-only

writes to your accounts

totalEstimatedAnnualSavings

multi-scenario aggregation

DRAFT · RUNNING · COMPLETED · FAILED

simulation states

How it works

Three steps. No agents. No surprises.

Define scenarios

Each scenario picks a resource and one of: DOWNSIZE (newInstanceType), RESERVED_INSTANCE (1y/3y term), SCHEDULE_STOP (start/end window), DELETE, or STORAGE_LIFECYCLE (transition + delete after N days).

5 primitives · per-resource

Run

POST /simulations/{id}/run executes a strategy per type: DownsizeStrategy compares current vs new instance price; ReservedInstanceStrategy applies the term discount; ScheduleStopStrategy applies the off-hours fraction; DeleteStrategy zeroes the cost; StorageLifecycleStrategy combines transition + retention math.

deterministic · per-resource

Compare & decide

Each run returns scenarioBreakdowns[] (with insights + warnings) plus a totalEstimatedAnnualSavings — share the URL with the team, decide, then act through the recommendation flow.

share · decide · act

What's inside

An interactive scenario engine that re-runs your last 90 days of cloud usage against any hypothesis: a new Savings Plan, a 30% traffic spike, a region migration, or a switch from on-demand to Spot — all on real data.

Hypothesis-driven, not vibes-driven

Drag a slider for commitment coverage, pick a target instance family, dial workload elasticity. The simulator replays 90 days of usage and produces a band, not a point estimate, so you sign with eyes open.

Stack scenarios

Combine 'move 40% of stateless to Spot' + 'sign 60% commit on m6i' + 'consolidate 3 regions to 2' and see the joint effect — including the second-order networking cost.

Sharable as a snapshot

Save a simulation and send the URL to finance, security or your cloud rep — they see the same numbers without poking around your account.

Capabilities

Everything you need on day one.

DOWNSIZE scenario
RESERVED_INSTANCE 1y / 3y
SCHEDULE_STOP off-hours window
DELETE (full cost reduction)
STORAGE_LIFECYCLE (transition + delete)
Multi-scenario aggregation
Per-scenario insights & warnings
100% read-only on your accounts

Before vs after Lumicost

Night and day.

Without Lumicost

Spreadsheet that conflates 5 levers into one
'What if we RI 30%?' → no answer for days
Buying the wrong RI eats the savings

With Lumicost

Five explicit primitives, composable
Scenario in seconds with annual savings
Compare 1y vs 3y before you commit

Where teams use it

Three ways teams put it to work.

Pre-renewal commitment sizing

Stop signing the renewal at last year's coverage — re-baseline against the last 90 days, not the last quarter's spike.

Black Friday capacity

Model a 4× burst with realistic auto-scaling latency and find the cheapest instance mix that doesn't blow your SLO.

Region consolidation

See egress, latency and cost effects of collapsing two regions into one — before kicking off the migration sprint.

From the field

“Five primitives composed cleanly will save more money than ten that nobody understands. We resisted the urge to ship a Monte Carlo for a reason.”

The Lumicost teamdesign principle

Plays nice with your stack

AWSGCPAzureOracle CloudKubernetesTerraformPulumiSlackJiraLinearGitHubGitLabDatadogSplunkOpenTelemetryPagerDutyNetSuiteSAPAWSGCPAzureOracle CloudKubernetesTerraformPulumiSlackJiraLinearGitHubGitLabDatadogSplunkOpenTelemetryPagerDutyNetSuiteSAP

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