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Andrew Graham-Yooll

Andrew Graham-Yooll

Having fun working with Product Engineering teams

Valencia, Valencian Community, ES
+34644125677
English, Spanish

Background


About

About

Hi there! I'm Andrew, living in Valencia, Spain. I specialize in optimizing distributed computing systems and streamlining web APIs to deliver efficient, scalable solutions. In my free time I enjoy surfing, tackling home improvement projects, tinkering with gadgets, and contributing to open-source initiatives.

Work Experience

Work Experience

  • Engineering Manager - Financial OperationsPrimer

    Aug, 2023 - Present

    Leading payments management engineering team at Primer, focusing on core platform systems powering merchant-facing products with emphasis on scalability, performance, and data-driven insights.

  • Tech Lead - ObservabilityPrimer

    Nov, 2021 - Aug, 20231 year 9 months

    At Primer, I worked on core platform systems powering merchant-facing products, with a focus on scalability, performance, and data-driven insights. My contributions modernized key dashboard experiences, improved developer and customer experience, and unlocked new business opportunities.

    • Rebuilt the Payments List page (one of the most used areas of the merchant dashboard), migrating queries from SQL to Elasticsearch + Kafka. Reduced query latency from ~30 seconds to <500ms across millions of payments with 100+ searchable attributes. Enhanced UX by enabling search and filtering on any attribute (e.g., customer name, amount, currency, address).

    • Led migration from DynamoDB to CockroachDB for all dashboard databases, delivering multi-regional support, more efficient querying, and a significantly improved developer experience aligned with business requirements.

    • Built the backend for an observability platform using Firebolt + CubeJS, enabling merchants to access rich charts and insights into payment performance. This became a commercial product line, generating hundreds of thousands in revenue.

  • Software Engineer + Tech Lead - Last Mile DeliveryMercadona Tech

    Apr, 2018 - Jul, 20213 years 3 months

    As part of the engineering team, I designed and scaled critical systems to support high-growth e-commerce operations and logistics. My work enabled the company to save significant costs, handle rapid demand surges, and establish a more resilient technical foundation.

    • Built a custom vehicle routing engine that optimized ~5,000 deliveries and 100+ vehicles in under 5 minutes, saving ~€100k annually and enabling future extensions such as multi-warehouse routing.

    • Developed and maintained Relé, an internal Python library leveraging Google Pub/Sub, which allowed seamless scaling of the e-commerce platform across multiple teams. It improved developer onboarding and reduced integration friction across services.

    • Designed and deployed an ETL platform using Relé, reducing monthly costs by thousands of euros while enabling reliable ingestion of data into Google BigQuery for cross-product analytics.

    • Migrated interservice communication from brittle HTTP to resilient async processes, while also setting company-wide publishing and subscribing standards.

    • Optimized e-commerce platform performance, helping all API endpoints consistently meet a 250ms SLO, a critical achievement during COVID-19 quarantines when online grocery ordering demand spiked dramatically.

  • Software EngineerSolaris Offgrid

    Aug, 2016 - Apr, 20181 year 8 months

    Lead development team to new features, products and tooling at Solaris Offgrid.

    • Lead development team to new features, products and tooling

    • Launch and maintain mobile and web applications

    • Focus on scaling from 100 to 100K+ clients

    • Containerized (Docker) all aspects of our software

    • Set up and optimize all our Continuous integration and continuous deployment strategies

    • Manage database persistence and integrity (PostgreSQL, SQLite and CouchDB)

    • Communicate with on the ground staff to solve tech issues

    • Prioritize issues and features brought forth by staff to better integrate technology into day-to-day business operations

    • Conduct development meetings and debriefing sessions as it pertains to our Agile development process

  • Web DeveloperPrincipal

    Aug, 2015 - Aug, 20161 year

    Freelance web development work in Washington D.C. Metro Area.

    • Develop and maintain web pages for businesses

    • Continual maintenance of servers and code base

    • Find balance with clients desires and best user experiences

Skills

Skills

  • Software Engineering

    Python

    Testing

    Open-Source Development

    Distributed Systems

    Web APIs

    Docker

    PostgreSQL

    Elasticsearch

    DynamoDB

    Google Pub/Sub

    Google BigQuery

    Firebolt

    CubeJS

  • Engineering Leadership

    Team Management

    Technical Leadership

    Engineering Management

    Agile Development

    CI/CD

    System Architecture

    Performance Optimization

    Scalability

Education

Education

  • Biology, General, Bachelor of Science, University of Maryland Baltimore County

    Jan, 2013 - Jan, 2016

Awards

Awards

  • Thomas V. Marsho & Martin Schwartz Memorial Fund Award , University of Maryland Baltimore County

    Awarded on: Jun 01, 2015

Volunteer Work

Volunteer Work

  • Volunteer, Django Girls

    Jan, 2014 - Jan, 2016

    Advisory board member for Mission to Heal in Washington D.C. Metro Area.

    • Manage donation chain for upcoming trips

    • Coordinate transport and relations with in-country hosts

Publications

Publications

Interests

Interests

  • Technology & Making

    Open-source contributionsTinkering with gadgetsHome improvement projects
  • Outdoor Activities

    SurfingCycling
References

References

  • Miquel Torres Barcelo
  • Siten Mandalia