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NorthStack

−38% cloud spend

NorthStack's AWS bill was growing faster than ARR. We stood up a multi-account landing zone, right-sized everything, and put FinOps guardrails in place — cutting spend 38% with zero downtime.

Industry
B2B SaaS · Logistics
Region
EU + US
Duration
11 weeks
Engagement
Cloud adoption + FinOps
The result
Monthly AWS spend
$92kfrom $148k
−38%
Compute / customer
$1.10from $2.40
−54%
Untagged resources
0%from 62%
−62pp
Infra incidents / mo
2from 9
−78%
The problem

What was broken

NorthStack ran everything in a single AWS account with no tagging, oversized EKS nodes, and three idle RDS replicas. The bill had grown 4× in 18 months while revenue grew 1.8×. There were no budgets, no anomaly alerts, and SOC 2 auditors had flagged the lack of account separation. Two engineers were spending ~30% of their week on infra firefighting.

The approach

What we did

  1. 1

    Designed a 4-account landing zone (prod / staging / shared-services / sandbox) using AWS Control Tower and Terraform modules.

  2. 2

    Right-sized EKS node groups based on 90 days of CloudWatch + Datadog data. Moved batch workloads to Spot, dev to t-family on schedule.

  3. 3

    Decommissioned two of three RDS replicas, moved analytics reads to a read-only replica with smaller instance class, enabled Performance Insights.

  4. 4

    Set up Cost Anomaly Detection, per-team budgets, and a weekly FinOps digest that emails engineering leads. Every resource is now tagged owner+env+service.

  5. 5

    Migrated 47 services account-by-account over 6 weekends. Zero customer-visible downtime; one 11-minute internal maintenance window.

Timeline

How it unfolded

Week 1-2
Discovery

Cost + architecture audit. SOC 2 gap analysis. Roadmap signed off.

Week 3-4
Landing zone

Control Tower, 4 accounts, Terraform modules, SSO.

Week 5-8
Migration

47 services moved account-by-account. Zero customer downtime.

Week 9-10
Right-sizing

EKS, RDS, networking. Spot for batch. Reserved Instances re-purchased.

Week 11
FinOps handover

Budgets, anomaly alerts, weekly digest, runbook.

They cut our bill 38% and gave us a cloud setup the auditors actually liked. Two of our engineers got their weeks back.
AP
Arjun Pillai
CTO, NorthStack