Infrastructure Case Studies
Real-world Infrastructure case studies: what happened in production, the architecture behind it, the numbers and the lessons to take to your own team.
How 37signals Saved $10M by Leaving AWS for Owned Hardware
37signals moved HEY and Basecamp off AWS to owned servers, projecting over $10M in savings over five years. The lesson: cloud economics invert at scale.
Infrastructure · intermediate · 12 min read
How a 120-Engineer SaaS Company Migrated from One AWS Account to a Multi-Account Landing Zone
A B2B SaaS company collapsed security blast radius and achieved compliance by adopting AWS Organizations, Control Tower, and SCPs — learning hard lessons about OU design and SCP ordering along the way.
Infrastructure · intermediate · 12 min read
How a B2B SaaS Team Cut CI and Batch Costs by 70% Using Spot Instances Without Losing Jobs
A 120-engineer SaaS team moved CI pipelines and nightly batch workloads to Spot/Preemptible instances, slashing compute bills by 70% through checkpointing, retries, and mixed instance-type pools.
Infrastructure · intermediate · 12 min read
How a B2B SaaS Team Cut Their AWS Bill by 40% with Rightsizing, Graviton, Savings Plans and S3 Lifecycle Policies
A 120-engineer SaaS company slashed its AWS spend by 40% in 90 days by combining instance rightsizing, Graviton3 migration, Compute Savings Plans, and aggressive S3 lifecycle tiering — without touching a single line of product code.
Infrastructure · intermediate · 12 min read
How a B2B SaaS Team Split a 4,000-Resource Terraform Monolith Into Modules Without Downtime
A 120-engineer SaaS company decomposed a single 4,000-resource Terraform state file into scoped modules and isolated state backends, cutting plan times from 22 minutes to under 90 seconds with zero production incidents.
Infrastructure · advanced · 12 min read
Lift-and-Shift to AWS First, Then Modernise: How a B2B SaaS Company Escaped the Data Centre
A 120-engineer B2B SaaS company migrated 47 workloads from ageing on-prem hardware to AWS in 14 months, cutting P99 latency by 60% and infrastructure spend by 34% after a deliberate two-phase approach.
Infrastructure · intermediate · 12 min read
The 2017 Amazon S3 Outage: One Mistyped Command and the Cost of a Slow Restart
A mistyped parameter in an S3 subsystem maintenance command removed too many servers, triggering a cascade that took down S3 in us-east-1 for ~4 hours and disrupted a large portion of the internet.
Infrastructure · beginner · 12 min read
The Atlassian April 2022 Outage: How a Maintenance Script Deleted 883 Customer Sites
A misconfigured maintenance script permanently deleted 883 Atlassian cloud sites; restoring them took up to 14 days due to brittle restore tooling and manual processes.
Infrastructure · intermediate · 12 min read
The Datadog March 2023 Outage: How an Automatic OS Update Severed Networking Across Tens of Thousands of Nodes
An automatic Linux security patch changed a kernel networking default, silently breaking connectivity across Datadog's multi-region fleet and taking down their own monitoring platform for hours.
Infrastructure · intermediate · 12 min read
The November 2023 Cloudflare Outage: When a Power Failure Took Down the Control Plane
A data centre power failure in November 2023 cascaded into a multi-hour Cloudflare control-plane and analytics outage, exposing hidden dependencies between the data plane and a single facility.
Infrastructure · advanced · 12 min read