Gareth Merrifield

Mercer Island, WA linkedin.com/in/gareth-merrifield garethmerrifield.com

Principal Product Manager — Tax & Finance Technology · Applied AI Automation & GenAI Prototyping

Summary

Principal Product Manager with 19 years at Amazon owning tax, finance, and compliance platforms from strategy through launch — reconciliation automation, compliance modernization, and e-invoicing / digital-reporting. Translates complex enterprise financial workflows into scalable products through cross-functional leadership across Tax, Accounting, and Engineering. A highly technical product leader who builds production-grade applied-AI systems hands-on in Python and AWS.

Core skills

Product & strategy
Product strategy · Roadmapping · Business requirements · Stakeholder management · Executive communication · Workflow transformation
Tax, finance & compliance
Tax technology · Compliance workflows · Financial systems · Reconciliation automation · Controls · Regulatory processes
AI & automation
Generative AI · LLM workflows · AI agents · MCP · Claude · OpenAI/ChatGPT · Python · APIs · AWS Lambda · S3 · EventBridge · SQL/SQLite

Professional experience

Principal Product Manager, Tax Technology — Amazon.com, Inc.
Nov 2022 – Present
  • Own product strategy and execution for Amazon's global tax compliance and reconciliation platforms, modernizing tax operations for an increasingly complex e-invoicing and digital-reporting environment.
  • Define multi-year product vision, UX strategy, and roadmap for global tax reconciliation capabilities spanning compliance, controllership, auditability, and operational scale.
  • Drove product discovery that reduced manual reconciliation effort and strengthened data transparency, controls, and auditability across tax, accounting, and finance-technology workflows.
  • Develop strategic narratives and executive-ready proposals that align senior tax, finance, and technology leaders around long-term modernization and investment priorities.
  • Drove an operations-facing product that lets the tax operations team manage compliance more efficiently, readying Amazon for emerging e-invoicing and digital-reporting obligations.
  • Partner across Tax, Accounting, Finance Technology, and Engineering to translate business requirements into product specs, workflows, and mockups — bridging domain experts and engineering.
Senior Product Manager, Finance Technology (eCFI) — Amazon.com, Inc.
Jan 2020 – Oct 2022
  • Product owner within Amazon's financial-systems product organization (eCFI). Promoted from PM III to Principal Product Manager.
  • Owned the end-to-end lifecycle of Checkbook, an automated daily bank-reconciliation platform replacing manual and semi-automated (Oracle) processes across Amazon's 2,900+ bank accounts.
  • Defined product vision via PR/FAQ (Amazon's product-strategy narrative) and go-to-market strategy; partnered with stakeholders on requirements and mockups.
  • Launched the first production release (minimum lovable product) in December 2021; secured product funding in 2018 and 2021 and led the organization's three-year strategy in both 2021 and 2022.
  • Authored the PR/FAQ for an intercompany settlement automation initiative ("Offset"), jointly funded by the Accounting and eCommerce Foundation SVP organizations.
Senior Program Manager, Finance Technology (eCFI) — Amazon.com, Inc.
Jan 2013 – Jan 2020
  • Progressed from finance-systems integration advisor ("Financial Bar Raisers," 2013–2014) into program and product ownership of Amazon's core finance platforms, supporting launches across Payments, Retail, Global Store, Prime, Advertising, and geo expansions.
  • Program lead for major financial-systems launches including new-country and tax restructures, upfront-charge payment methods, Global Installment Lending, and legacy-system deprecations.
  • Led the Order-to-Cash (OTC) subledger migration onto Amazon's unified financial subledger (2015–2016).
  • Acting product manager, Order-to-Cash (2017): reduced the onboarding process to 0.2 days from 1.04 days.
  • Acting product manager, subledger adjustments (2017–2018): launched a non-technical UI letting accountants prepare and approve transaction-level subledger adjustments.
  • Acting product/program manager, Disbursement-to-Cash (2019): automated daily reconciliation of seller-disbursement bank accounts and launched the US Amazon Payments entity, covering 60% of worldwide seller-disbursement traffic.
Accounting, Payments & Treasury (FAI–FAIII) — Amazon.com, Inc.
Aug 2007 – Jan 2013
  • Progressed across Treasury and Payments accounting: owned month-end journal entries and multi-geography reconciliations; led OTC subledger cleanup and Amazon Currency Converter reconciliation automation.
  • Built Excel VBA tooling to streamline 100+ monthly reconciliations; supported geography expansions (ES, IT, Checkout by Amazon-UK), International Disbursement for Merchants, and Amazon Currency Converter launches.
Cash Staff Accountant — Savers, Inc.
Oct 2006 – Aug 2007
  • Prepared month-end journal entries and reconciled bank accounts for Canadian and Australian subsidiaries; performed daily/weekly store-sales variance analysis and documented close procedures.

Applied AI & automation portfolio

Self-directed builds applying LLMs, agentic workflows, and cloud automation to real finance, research, and operational problems. Code at github.com/garethmerrifield83.

AI Investment Research Monitor

Python · LLMs (OpenAI + Claude) · MCP · APIs
  • Designed and built an end-to-end portfolio-analysis system that screens ~3,000 equities daily across three risk profiles, then routes a bounded candidate set through a multi-stage LLM pipeline — per-symbol analyst, CIO-style synthesizer, and automated red-team critique — modeled on a real investment team.
  • Architected a hybrid deterministic-plus-LLM design: a rules-based screener does the broad, cheap work while LLM calls are reserved for high-value decisions — governed by an MCP data server, provider routing to cost-appropriate models, and hard per-run token budgets.
  • Built a closed learning loop that mirrors recommendations to a paper-trading sandbox, scores them against forward outcomes, and feeds results back into tuning, with live execution disabled by default as a safety control.

AI Daily Digest

Python · AWS Lambda · EventBridge · S3 · OpenAI
  • Built a serverless research-and-summarization workflow that aggregates multiple data sources and delivers a single mobile-friendly digest on a schedule, running unattended on AWS Lambda and EventBridge.
  • Constrained the LLM to a JSON-schema-validated summarizer for predictable, automatable output, and engineered for cost and resilience with per-call token accounting, an S3-backed cache, and a modular design that degrades gracefully if any source fails.

Personal AI / Product Portfolio Platform

HTML/CSS · AWS (S3) · Architecture writing
  • Designed and shipped a public, AWS-hosted portfolio site that reframes technical AI builds as product narratives — architecture diagrams, design decisions, and outcomes per project.
  • Establishes a personal brand as a finance and product leader actively building with applied AI.

Education

B.A., Business Administration (Accounting) — Seattle University, Seattle, WA

Graduated August 2006 · Cumulative GPA 3.91 (summa cum laude)

Certifications