Mike Hall

Staff Software Engineer

Summary

Staff software engineer who stabilizes revenue-critical platforms, reduces systemic risk, and makes complex systems understandable enough for teams to change safely. Strongest in platform architecture, legacy modernization, observability, incident leadership, and cross-team execution across Ruby on Rails and PostgreSQL systems. Known for turning production ambiguity into clear operating models, durable remediation plans, and safer delivery.

Core Skills

  • Platform Architecture
  • Technical Strategy
  • Legacy Modernization
  • Reliability Engineering
  • Incident Leadership
  • Observability Strategy
  • Cross-Team Technical Leadership
  • Risk Reduction
  • Platform Enablement
  • Ruby on Rails
  • PostgreSQL
  • OpenTelemetry

Experience

Associate Director, Staff Engineer

OneMain Financial | Remote | -

Owned architecture, production health, and systemic risk for a revenue-critical acquisition platform in a regulated financial environment.

  • Served as the final escalation point for high-severity production incidents, leading cross-team diagnosis and driving remediation plans with clear ownership.
  • Reconstructed end-to-end customer acquisition flows across browser, application, middleware, and downstream business systems, giving teams an authoritative operating model for incident response and change planning.
  • Re-architected session state handling in multi-step application flows, removing a persistent integrity failure mode affecting customer tracking and incident recovery.
  • Founded and led the OpenTelemetry Working Group, establishing shared observability standards adopted across engineering and cybersecurity teams.
  • Created an enablement function that separated platform risk and remediation work from feature delivery, sustaining long-horizon stability improvements.

Senior Backend Developer

SK Holdings, Inc. | Chicago, IL | -

Stabilized and modernized a shared Rails platform supporting multiple digital properties, millions of users, and high-volume data flows.

  • Upgraded Ruby and Rails across multiple applications, reducing technical debt, security exposure, and long-term maintenance risk.
  • Built data pipelines synchronizing millions of records between internal systems and third-party services to support high-volume operations.
  • Replaced expensive dynamic queries with materialized views and moved session and cache load from MySQL to Redis, improving performance under load.
  • Optimized CI by reordering and parallelizing test execution, shortening feedback cycles and improving delivery throughput.

Senior Software Developer

BenchPrep | Chicago, IL | -

Improved correctness, performance, and security for enterprise assessment workflows where calculation accuracy and response integrity were business-critical.

  • Eliminated assessment calculation errors by analyzing and tuning critical PostgreSQL queries with EXPLAIN ANALYZE and query-planning tools.
  • Implemented JWT-based response verification and once-only processing to prevent tampering and strengthen trust in assessment outcomes.
  • Designed a secure cross-origin communication API for embedded client applications and reduced high-concurrency bottlenecks in assessment workflows.

Additional Experience

  • Senior Software Developer, ActiveCampaign | September 2018 - December 2018 | Chicago, IL : Improved testability, performance, and change safety inside a tightly coupled CRM core.
  • Senior Software Developer, ReachLocal | March 2015 - November 2016 | Remote : De-risked a large legacy rewrite by proposing an incremental modernization strategy built around API boundaries.
  • CTO, KloboMedia | March 2014 - September 2016 | Remote : Built and delivered a social media analytics platform as technical co-founder and CTO.
  • Core Team Lead, Coderwall | January 2014 - December 2014 | Remote : Relaunched the platform as open source and modernized background jobs and data storage to reduce cost and improve maintainability.

Earlier Experience

Built enterprise systems, startup platforms, and revenue-critical fulfillment services across consulting, product, and operational environments.

  • TicketsNow: Designed and delivered a real-time inventory locking and order fulfillment service that generated more than $2 million in annual revenue.
  • Groupon and Obtiva: Led onboarding, mentoring, and engineering enablement work while delivering backend systems in high-growth and consultancy environments.
  • BrightStar, Motorola, BP, and earlier enterprise roles: Built integration and operational systems across large organizations with a foundation in .NET, SQL, and production support.