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"There are only two hard things in Computer Science: cache invalidation and naming things." This decades-old quip gets endless variations, but DoorDash's Matt Ranney offers a more contemporary contender: system migrations might actually be the hardest problem in computing. In a revealing case study, Seeq engineer Steven Oxley validates this claim through the lens of career development, drawing from his experience migrating a SaaS platform from virtual machines to Kubernetes.

The Triple Threat of Migration Complexity

Oxley's migration of 200+ customer deployments wasn't just technically demanding—it was a three-dimensional challenge:

  1. People Leadership: Building a dedicated Kubernetes team required clearing organizational bandwidth and maintaining momentum amid competing priorities
  2. Project Orchestration: Coordinating downtime windows across global customers demanded meticulous planning (spearheaded by colleague Olivia Reagan), with constant risk of stalling without relentless focus
  3. Technical Innovation: Designing cloud-agnostic infrastructure led to breakthroughs like the Python-built "migration-controller"—a custom Kubernetes operator that automated data synchronization via rsync and DNS cutovers

"This migration-controller was a fun challenge. None of us had written a Kubernetes controller before, but it hasn't been our last," Oxley notes, highlighting the PostgreSQL-specific rsync optimizations and Kubernetes watch API lessons learned.

Career Dividends of Embracing the Hard Path

While many senior engineers gravitate toward greenfield projects, Oxley argues migrations offer unique professional advantages:
- Technical Mastery: Exposure to infrastructure design, distributed systems, and cloud-native tooling creates T-shaped engineers
- Strategic Impact: Successfully migrating enabled Seeq's fleet-wide automation and continuous delivery—capabilities previously "monumental" without Kubernetes
- Career Acceleration: Oxley directly attributes his promotion to the migration's success, calling it "the most difficult project" of his career

The Migration Imperative

Ranney's observation that migrations are "hard problems that many senior engineers avoid" rings true across the industry. Yet as Oxley concludes:

"Migrations are the hardest problem that almost every professional software engineer will encounter. When faced with one, don't shy away—see it for the career rocket fuel it is."

The Kubernetes migration case proves that while cache invalidation remains tricky, orchestrating complex transitions builds engineers who can navigate any architectural frontier.

Source: Steven Oxley's Blog