Mike Hall

Principal Software Engineer

Role & Career Context

Detailed experience breakdown, architectural achievements, and related archival artifacts.

Senior Software Developer

ActiveCampaign | Chicago, IL | -

Owned core system testability and performance at scale, leading legacy modernization in a highly coupled CRM platform.

  • Legacy Boundary Isolation: Decoupled critical legacy constraints behind explicit service boundaries, eliminating high-risk direct database dependencies and establishing clean execution paths.
  • Data Access & Query Optimization: Replaced ad-hoc global state access with structured query patterns and multi-tier caching strategies, accelerating throughput for high-volume database reads.
  • Frontend Test Hardening: Hardened the Ember.js frontend test suite across complex CRM user workflows, enforcing testable state boundaries and reducing regressions in customer-facing flows.
  • Test-Driven Observability: Established test-driven observability patterns across legacy PHP codepaths, shortening developer feedback loops during high-risk production debugging.

Skills: PHP, MySQL, Ember.js, JavaScript, Legacy System Modernization, Backend System Architecture, Automated Testing, Performance Optimization