Mike Hall

Staff Software Engineer

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Role & Career Context

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

Associate Director, Staff Engineer Verified Case Study →

OneMain Financial | Remote | -

Appointed as Senior Technical IC and Software Architecture Lead for the Acquisition lane of a regulated financial enterprise. Mapped the entire loan acquisition and origination pipeline end-to-end from visit to booked loan using the Panoramic View technique of longitudinal and latitudinal analysis from desktop browser to mainframe and back again at each step, and applied the same depth to the Affiliate API. Engineered an automated 5-phase PII deletion engine across 30+ tables, deployed enterprise distributed observability, and guided cross-team platform reliability.

  • Originations IC Delivery & Instant Disbursement: Led the Originations Verification squad through consecutive Exceeds Expectations ratings, architecting and shipping an instant loan disbursement pipeline (funding to debit cards in minutes). Appointed Software Architect for the Acquisition Lane, later converting to Associate Director, Staff Engineer.
  • Acquisition Workflow Enablement & Architecture Discovery: Founded the Acquisition Lane enablement team; mapped the loan acquisition and origination pipeline end-to-end from visit to booked loan (desktop browser to mainframe and back again at each step) and the Affiliate API at the same depth, identifying seven distinct lending funnels with a tracking initiative; architected an automated 5-phase PII remediation deletion engine across 30+ tables.
  • Enterprise Resilience & DynamoDB Session Remediation: Diagnosed and eliminated a critical session-cookie overflow defect that caused 4% silent traffic loss of digital loan applications during e-signing; architected zero-downtime blue/green migration to DynamoDB session store with zero incidents.
  • Enterprise Trace & Operational Alignment: Architected distributed telemetry across Rails distributed monoliths, MuleSoft APIs, and IBM mainframe backends; partnered directly with Cybersecurity, EMC, SRE, and Incident Command to align monitoring with end-to-end distributed tracing.
  • Community Enablement & SRE Handoff: Founded weekly Geekfest@OMF and scaled the enterprise OpenTelemetry Working Group to 40+ cross-lane engineers; mentored and partnered with SRE leads to transition ongoing operational facilitation, establishing a durable community of practice.
  • Applied AI & Innovation Leadership: Placed in two corporate hackathons building conversational agents with Rasa and a schema inference prototype; pioneered local LLM orchestration and privacy-conscious AI developer tooling at Geekfest@OMF.

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

The System Constraint: Over years of rapid business expansion, high-volume financial customer loan application and origination flows accumulated implicit lateral state dependencies across multi-service Rails state machines, MuleSoft APIs, and IBM mainframe backends. Client-side session cookie bloat caused a persistent session-cookie overflow defect that silently corrupted state and dropped 4% of digital applications between offer selection and e-signing.

Architecture Discovery & Technical Execution

Interaction Surface Mapped the entire loan acquisition and origination pipeline end-to-end from initial visit to booked loan across browser, mobile, and Affiliate API ingress points, identifying seven distinct lending funnels through a dedicated tracking initiative.
Lateral & Implicit State Dependencies Inventoried the intersection of business rules, customer actions, and system state changes; mapped 40+ applicant database tables, isolated legacy clarity_ and underwriting_ orphan data, and architected an automated 5-phase PII deletion engine.
Full-Stack Network & Boundary Topology Conducted longitudinal and latitudinal analysis across the process sequence, tracing each step from desktop browser down through Rails services and MuleSoft integration layers to IBM mainframe backends and back again to establish the unified Enterprise Trace.
Supply Chain & Vulnerability Exposure Audited third-party credit bureau APIs, e-sign vendor webhooks, and boundary ingress points, providing real-time causal event chains for cybersecurity and fraud investigations.

Measured Engineering & Business Outcomes

  • Diagnosed and resolved a persistent session-cookie overflow defect affecting 4% of digital applicant traffic by implementing custom rescue middleware and migrating Rails session state to AWS DynamoDB with zero downtime.
  • Engineered an automated 5-phase PII remediation engine across 30+ tables, eliminating legacy orphan references without disrupting live application state.
  • Mapped the entire loan acquisition and origination pipeline end-to-end from visit to booked loan, connecting desktop browser, Rails, MuleSoft, and mainframe backends with distributed tracing to accelerate root-cause diagnosis for Incident Command.
  • Partnered with Cybersecurity and Enterprise Monitoring Center (EMC) to bridge immediate operational monitoring with long-term distributed telemetry and causal event attribution.
  • Unblocked continuous legacy modernization by establishing verified state change gates across distributed Rails services.
  • Founded and technically led Acquisition Lane enablement for privacy remediation, modernization, and growth-team support, while leading a 3-year enterprise community arc through Geekfest@OMF and the OpenTelemetry Working Group, then transitioning stewardship to SRE.

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