Professional background
About Efrain Castillo
FP&A, accounting, and analytics
I'm a finance professional with 8+ years of experience across fintech, SaaS, marketplace, and foundation environments. My work connects operating drivers to forecasts and financial decisions, with the accounting and reconciliation discipline to make the underlying numbers reliable.
Forecasting and business partnership at Jaris
At Jaris, I owned quarterly and annual forecasts for a $50M+ fintech loan portfolio. I modeled origination volume, revenue, credit losses, and contribution margin, and analyzed forecast-versus-actual performance to explain changes in volume, pricing, and borrower performance.
I built driver-based models and base, upside, and downside scenarios to evaluate growth, pricing, and portfolio-risk trade-offs. Working across Finance, Product, and Risk, I also standardized KPI definitions and reconciliation logic so operating reviews and financial reporting used consistent measures.
Public-company accounting and analysis at Poshmark
As a Senior Accountant at Poshmark, I supported IPO readiness and SEC reporting, owned critical close processes, and built budget-versus-actual reporting. My work included marketplace performance analysis, capitalized software, and collaboration with Product and Operations to connect business activity with financial results.
Capital investment and financial systems at Egnyte
At Egnyte, I worked on ROI and CapEx analysis for $10M+ initiatives, expenditure and variance reporting, and accounting responsibilities including fixed assets, prepaids, and accruals. I also supported the transition from QuickBooks to NetSuite and improvements to purchasing and reporting workflows.
Controls and reporting reliability at Hewlett
I currently work as a contract Senior Accountant through DeWinter Group at the William and Flora Hewlett Foundation. My work supports monthly close, cash reconciliation, financial reporting, controls, and process documentation, strengthening the accuracy and auditability of financial information used by Finance.
Selected analytical work
My self-directed portfolio cases show how I approach forecasting and business decisions. They use synthetic data and are separate from my employment experience.
- SaaS Growth Economics — recurring revenue, retention, ARR bridges, and reconciliation controls.
- Marketing Investment Economics — acquisition cost, contribution-margin payback, and downside sensitivity.
- Merchant Revenue Forecasting — out-of-sample comparison of forecasting methods and a practical planning framework.
Education and tools
I hold an MBA, an MA in Applied Economics, and a BS in Finance from San José State University, along with the Financial Modeling & Valuation Analyst certification. I use Excel, SQL, and Python for financial modeling, analysis, validation, and reporting automation, with experience in finance systems including NetSuite and Sage Intacct.