# Greg T. > Senior Infrastructure Engineer | 4-nines uptime, zero-downtime migrations, and multi-region scaling for AI startups | AWS, Terraform, PostgreSQL Location: San Francisco Bay Area, United States Profile: https://flows.cv/gregt I build the infrastructure that lets AI startups scale without thinking about infrastructure. At Modern Treasury, I architect multi-region cell infrastructure for a payments platform running at 4 nines. The work I'm best at: migrating customers between AWS regions with <5 minutes of downtime, upgrading PostgreSQL 14 to 17 under live traffic, rolling out database partitioning at scale, and making Terraform configs that other engineers actually want to contribute to. What I've shipped recently: - Launched new AWS regions and cells with re-architected pipelines, observability, and deploy tooling - Upgraded core systems under live traffic: Redis to Valkey, Ruby 3.2 to 3.4 (YJIT), Rails 7 to 8, PostgreSQL 14 to 17 - Improved GraphQL reliability from 2 nines to 3 nines - Cut Aurora failover impact through pgbouncer tuning and hardened SQS/DNS infrastructure - Refactored Terraform to be config-driven and region-agnostic I also managed a 9-person infrastructure team for two years. I chose to go back to IC because I'm at my best when I'm deep in the systems. But that management experience means I can drive cross-team initiatives, align with stakeholders, and unblock myself without waiting on anyone. Before Modern Treasury: 12 years at Arrow Electronics building high-throughput APIs (4.5M requests/day at 30ms) and internal platform tooling for a Fortune 500. Always happy to talk about multi-region architecture, database migrations under load, or Terraform at scale. ## Work Experience ### Software Engineer @ Modern Treasury Jan 2026 – Present | San Francisco, CA - Building and scaling multi-region cell infrastructure for a payments platform running at 4 nines - Core contributor to Terraform, observability, and CI/CD infrastructure across AWS regions ### Engineering Manager, Infrastructure @ Modern Treasury Jan 2024 – Jan 2026 | United States Managed 9 engineers while staying deep in technical delivery. Returned to IC by choice. - Launched new cells (us002, us005) and a new AWS region (us-east-1), re-architecting pipelines and tooling for multi-region support - Orchestrated cross-region customer migrations with <5 min downtime - Rolled out ParadeDB across cells, implemented database partitioning at scale, automated new cell creation - Upgraded core systems with minimal downtime: Redis to Valkey, Ruby 3.2 to 3.4 (YJIT), Rails 7 to 8, PostgreSQL 14 to 17 - Elevated system availability to 4 nines; improved GraphQL reliability from 2 nines to 3 nines - Refactored Terraform to config-driven, modernized Lambdas to region-agnostic - Reduced Aurora failover impact via pgbouncer tuning; hardened SQS and DNS infrastructure ### Software Engineer @ Modern Treasury Jan 2022 – Jan 2024 | San Francisco, CA - Built SLO instrumentation for Sidekiq, API, and cell router - Migrated infrastructure from CloudFormation to Terraform, enabling team-wide contributions - Led egress IP migration for bank integrations without proxy overhead - Built developer tooling: mt-onboard (workstation setup) and tf-infrastructure (scalable Terraform foundation) - Drove cost efficiency through AWS/Datadog optimization and autoscaling tuning ### IT Senior Enterprise Architect @ Arrow Electronics Jan 2010 – Jan 2022 - Part inventory search API spanning two data centers: 4.5M daily requests, 30ms average latency - Real-time global inventory tracking enabling faster inter-region transfers - Performance tracker processing 18M+ datapoints/day for exec reporting - Designed company-wide API-first architecture strategy using gateways to secure and scale services - IoT control systems (Monnit sensors, Fetchcore robots) for warehouse automation - SOX compliance audit system enforcing segregation of duties ### Director of Technology @ Trinity International Industries Jan 2009 – Jan 2010 - Automated manual operational workflows, built eCommerce platform, managed IT infrastructure for company relocation ### Systems and Software Engineer @ Flight Deck Resources Jan 2006 – Jan 2009 - Custom touchscreen applications for airline cockpit and cabin environments (pre-iOS era) - Proprietary update delivery system for embedded environments with limited connectivity ### Earlier Roles @ Various Companies Jan 2003 – Jan 2006 Informative Research -- .NET Developer (2005-2006). Credit reporting web services. UC Irvine -- Software Developer (2001-2005). Campus systems and internal tools. Boeing -- Intern (2003-2004). ## Education ### M.S. in Computer Science The Polytechnic Institute of New York University ### B.S in Information Computer Science UC Irvine ## Contact & Social - LinkedIn: https://linkedin.com/in/gregtam - Website: http://www.gregtam.com --- Source: https://flows.cv/gregt JSON Resume: https://flows.cv/gregt/resume.json Last updated: 2026-04-05