Mike Hall

Principal Software Engineer

PDF Resume Case Studies → Formats (TXT / MD)

Role & Career Context

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

Associate Director, Staff Engineer

OneMain Financial | Remote | -

Served as Senior Technical IC and Software Architecture Lead for the Acquisition lane of a regulated financial enterprise, combining hands-on system cartography with production stability, modernization, observability, and cross-team technical direction.

  • Full-Stack Dependency Cartography: Reconstructed end-to-end customer journeys spanning browser interaction surfaces, API gateways, application middleware, and legacy database layers, establishing a unified operational risk model for incident response and change governance.
  • Incident Response & Technical Escalation: Served as final escalation point for high-severity outages, translating live root-cause investigations into stronger telemetry, explicit component ownership, and reusable system knowledge.
  • Lateral State Coupling De-risking: Refactored fragile multi-step Rails workflow state machines, eliminating hidden lateral state mutations across asynchronous boundaries and resolving persistent data integrity failures in core acquisition flows.
  • Platform Enablement & Responsibility Realignment: Realigned Acquisition engineering around explicit business boundaries, then founded and technically led ACQ Enablement to protect platform reliability, remediation, and modernization work from feature pressure.
  • Observability & Boundary Instrumentation: Founded and led an enterprise OpenTelemetry initiative, instrumenting legacy microservices and third-party API supply-chain boundaries to convert dark system behavior into quantifiable telemetry and reduced MTTD.
  • AI-Augmented Systems Investigation: Introduced privacy-conscious local AI workflows for legacy code analysis and engineering support, expanding investigative capacity while keeping human review, security constraints, and source evidence explicit.

📐 Case Study: De-Risking Legacy Acquisition Workflows & Enterprise Telemetry

The System Constraint: Over years of rapid business expansion, high-volume financial customer acquisition flows accumulated implicit lateral state dependencies across multi-service Rails state machines and third-party API integrations, creating silent data corruptions and high incident escalation overhead.

Cartography & System Discovery Execution

Interaction Surface Mapped browser, mobile, automated API, and AI agent entry points across customer acquisition journeys.
Lateral & Implicit State Dependencies Identified shared global state mutations and uncoupled multi-step Rails state transitions, eliminating data corruptions.
Full-Stack Network & Boundary Topology Led enterprise OpenTelemetry deployment across legacy microservices, instrumenting third-party API boundaries.
Supply Chain & Vulnerability Exposure Audited third-party vendor APIs, webhooks, and ingress points to establish real-time boundary observability.

Measured Engineering & Business Outcomes

  • Reduced Mean-Time-To-Detection (MTTD) and mean time to resolution across high-severity acquisition outages.
  • Founded and technically led ACQ Enablement team to protect platform reliability, remediation, and modernization work.
  • Converted dark system behaviors into measurable telemetry, giving leadership an empirical foundation for architecture decisions.

Skills: Cross-Team Technical Leadership, Platform Architecture, System Cartography, Lateral State Dependency Mapping, System Resilience, Incident Leadership, Observability, OpenTelemetry, Legacy System Modernization, Distributed Systems, Ruby on Rails, PostgreSQL, AWS