[RH:] case-studies

Case Studies: How We Help Companies Stabilize Their Systems

Anonymized stories of real problems and how they were solved.

How We Stabilized a £2M/Day E-Commerce Checkout That Was Losing 8% of Orders

A UK e-commerce company with £2M in daily transaction volume was silently losing 8% of checkout completions. The issue had existed for 11 months. Three investigations had found nothing. Customer complaints were attributed to "user error."

Result: Checkout completion: 92% → 99.4% in 72 hours. Estimated recovery: £160,000/day. Fix took 3 days. Investigation took 1 week.

e-commercepaymentsobservability

Extracting Knowledge from a 400k-Line Ruby Monolith Before the Last Senior Engineer Left

A SaaS company with 3,200 customers had a 400k-line Rails monorepo built over 9 years. The CTO was leaving in 60 days — the only person who understood the billing system, custom reporting engine, and the largest enterprise integration.

Result: New CTO onboarded in 6 weeks vs estimated 6 months. Billing system: 94 new tests, complete architectural docs. Zero billing incidents in 8 months after (vs 4 in the 8 months before).

legacyknowledge-transferruby

Reversing a Microservices Migration That Was Making Things Worse, Not Better

A fintech startup had spent 14 months migrating from a Django monolith to 23 microservices. Deployment: 12 min → 4 hours. Incidents tripled. 40% of engineering time went to inter-service issues instead of product.

Result: Deployment: 4 hours → 18 minutes. Incident rate: pre-migration baseline. Feature time: 60% → 87%. More shipped in 3 months post-consolidation than in the previous 9.

microservicesarchitecturefintech

Modernizing a Healthcare Compliance System Under GDPR and HIPAA Constraints

A European healthcare software company serving 140 hospitals needed to modernize their patient data processing pipeline to meet updated GDPR enforcement requirements — with a 90-day regulatory deadline. The system had been built in 2014, ran on a single server with manual deployment, and had no automated test suite.

Result: Compliance deadline met with 2 weeks to spare. 340 characterization tests now covering the anonymization pipeline. Zero patient data incidents during the migration. Automated deployment reduced deployment time from 4 hours to 22 minutes.

healthcarecompliancegdpr