# Mike Hall **Staff Software Engineer** Chicago, IL - Email: [mike@just3ws.com](mailto:mike@just3ws.com) - Phone: [(847) 877-3825](tel:+18478773825) - Website: [just3ws.com](https://www.just3ws.com) - LinkedIn: [linkedin.com/in/just3ws/](https://www.linkedin.com/in/just3ws/) - GitHub: [github.com/just3ws](https://github.com/just3ws) --- ## 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, Distributed Systems & Async Processing, AI-Augmented Engineering & SDLC, Technical Strategy, Legacy Modernization, Reliability Engineering, Incident Leadership, Observability Strategy, Cross-Team Technical Leadership, Risk Reduction, Platform Enablement, Ruby on Rails, PostgreSQL, Sidekiq & Redis, LLM Orchestration (Claude, Gemini, Codex), OpenTelemetry --- ## Experience ### Associate Director, Staff Engineer at OneMain Financial **January 2021 - February 2026** | Remote Owned lane-level architecture, production stability, and systemic risk for a revenue-critical customer acquisition platform in a highly regulated financial environment. **Key Outcomes:** - Re-architected fragmented engineering ownership into a single accountable operating model by reconstructing end-to-end execution flows, eliminating assumption-driven debugging and enabling reliable change planning across disconnected teams. - Founded and operationalized the ACQ Enablement team to separate platform risk from product delivery, enabling sustained progress on systemic stability without degrading customer-facing velocity. - Converted incident response into a repeatable system of record by establishing trace-driven diagnosis and correction loops, ensuring every major failure resulted in measurable improvements to monitoring and cross-system integration. - Led enterprise adoption of OpenTelemetry, standardizing observability across engineering and cybersecurity to shift teams from intuition-based debugging to shared, trace-based reasoning. - Modernized legacy Rails platform components under continuous production load by re-architecting multi-step workflows and state handling, eliminating data integrity failure modes while maintaining uninterrupted revenue funnel operation. - Established systemic risk management as an explicit engineering responsibility, identifying cross-system failure modes to move the organization from reactive response to proactive reliability engineering. ### Senior Backend Developer at SK Holdings, Inc. **January 2019 - December 2020** | Chicago, IL Stabilized and modernized a shared Rails platform supporting multiple digital properties, millions of users, and high-volume data flows. **Key Outcomes:** - Modernized and upgraded core Ruby and Rails stacks across multiple applications, reducing technical debt and improving long-term maintainability. - Expanded operational visibility by introducing centralized logging and monitoring, working with providers to establish actionable insight into system capacity. - Designed and built robust data pipelines synchronizing millions of records to enable reliable high-volume operations and new business initiatives. - Led data-layer remediation by replacing expensive dynamic queries with Materialized Views, materially reducing load on reporting and analytics workloads. - Migrated session and cache workloads from MySQL to Redis to isolate transactional databases and improve response times under peak traffic. - Optimized CI pipelines by reordering and parallelizing test execution, materially reducing feedback cycle time and improving throughput. ### Senior Software Developer at BenchPrep **March 2017 - February 2018** | Chicago, IL Improved correctness, performance, and security for enterprise assessment workflows where calculation accuracy and response integrity were business-critical. **Key Outcomes:** - Diagnosed and eliminated assessment calculation errors by analyzing and optimizing critical PostgreSQL queries, improving accuracy and reducing response times for certification assessments. - Implemented JWT-based response verification to prevent tampering and enforce once-only processing, strengthening trust in submitted platform outcomes. - Designed and built a secure cross-origin communication API for embedded client applications, establishing explicit trust boundaries and safe integration patterns for enterprise clients. - Reduced operational risk by identifying and resolving performance bottlenecks affecting high-concurrency assessment workflows. - Improved delivery reliability by introducing lightweight team practices that clarified acceptance criteria and reduced rework. --- ## 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 **1999 - 2014** 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.