About

I’m a software engineer based in NYC with over a decade of backend experience across fintech and observability. I studied computer science at the University of North Carolina.

During nearly eight years at Square (now Block), I worked across multiple teams and roles, including a year as an engineering manager. I also participated in engineering hiring as an interviewer and later as a calibrator in hiring and promotion decisions.

I started on tooling for fraud investigation and KYC, then moved to mobile payments security where I built infrastructure and detection capabilities for Square’s Chip & PIN expansion. After transferring to Cash App, I worked on and later led a team building platform services for notifications and client data syncing, including migrating significant portions of the legacy monolith to new microservices on AWS.

Currently, I work at Chronosphere as an engineer on the distributed tracing product.

Experience

Chronosphere

January 2022 - Present chronosphere.io

Tracing

January 2022 - Present

I joined the tracing team before general availability and have worked on the product through its evolution into a production offering. As a backend engineer on a small team, I work across the stack: trace ingestion pipeline, query service, control plane primitives, trace metrics, and supporting services. I’ve also helped shape product direction from an operator’s perspective, informed by years of on-call experience.

Skills:

  • Golang
  • Kubernetes, Helm, Starlark
  • MySQL, ClickHouse
  • Data intensive application design

Cash App

October 2019 - January 2022 cash.app

Product Platform

October 2019 - January 2022

The Product Platform team built shared services to support product development across Cash App’s distributed architecture.

As an IC, I built a notifications platform service and migrated notification logic and data from the legacy monolith. I contributed to event-driven architecture patterns and collaborated with the security team on projects involving sensitive customer data.

From August 2020 to August 2021, I managed a team of 5 engineers focused on monolith decomposition. We migrated the backend logic and data for customer activity history to new services.

Skills:

  • Engineering management
    • Annual and quarterly planning
    • Mentorship and coaching
    • Performance review, compensation/promotions
  • Java, Kotlin, MySQL, Vitess, DynamoDB, Kafka
  • Event sourcing
  • Monolith decomposition and migration

Square

June 2014 - October 2019 square.com

Mobile Security

March 2016 - October 2019

The mobile security team built and operated infrastructure to ensure Square sellers’ mobile devices were safe for payment processing, including software PIN entry. This infrastructure ran in the critical path of all Square chip payments on millions of consumer devices.

I joined with backend experience and rearchitected the primary detection service for high availability. I then expanded into full-stack development of detections for Android and iOS, including heuristic rules and ML features, while applying cryptographic primitives for data protection and anti-tamper capabilities.

I monitored mobile platform changes and emerging threats to develop new detections. I collaborated with mobile, risk, and hardware teams, and advocated for processes to safely evaluate detection efficacy before enforcement.

Skills:

  • Java, Guice, MySQL, C
  • Android security and threat modeling
  • Anti-tamper software techniques
  • Applications of cryptography
  • Protocol design
  • BigQuery, Snowflake, ETL

Further related reading: PCI: Software PIN Entry on COTS

Internal Product

June 2014 - March 2016

I built features for internal tools used by risk, fraud, compliance, and support teams. Projects included a service for managing US customers’ 1099-K tax forms (with a data science pipeline for form generation) and batch processing infrastructure to screen customers against compliance-mandated data sets. I collaborated with risk, compliance, and finance teams.

Skills:

  • Ruby on Rails, MySQL
  • Secure handling of PII

Education

University of North Carolina at Chapel Hill

Master of Science, Computer Science — 2013 - 2014

Advisor: Dr. Diane Pozefsky. Graduate TA for “Internet Services & Protocols” and “Operating Systems” with Dr. Kevin Jeffay.

Bachelor of Science, Computer Science — 2009 - 2013

Graduated with Highest Distinction.