William Callahan

CFA Charterholder · CFP® Professional

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San Francisco, Californiawilliamcallahan.comaventure.vc
X (Twitter)@williamcallahanlinkedin.com/in/williamacallahan

Professional Summary

Software engineer and leader experienced in data, search, finance, and AI-powered web applications. Deep background in product development and quantitative research.

Highlighted Technical Projects

aVenture.vc

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AnalyticsData PlatformResearch ToolBusiness IntelligenceSaaSWeb Application

A data platform for researching private startup companies and venture investors. Requires orchestration of 10s of millions of database records across 500+ keys. Live data pipelines and ETL, with near instant processing of news articles, company data, and other to contribute updates daily. Built with Node.js, Next.js, TypeScript, Zod, PostgreSQL and many others.

williamcallahan.com

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Graph IndexS3 Object StorageInteractive AppTerminal UIMDX BlogSearch

Personal site with dynamically generated graph index of thousands of json documents. Dynamically fetches images (logos, opengraph images) and scrapes/crawls, and parses external websites for external links. Built with Next.js App Router, TypeScript, and Tailwind; Dockerized for cloud deployment, which I do with all my deployments.

SearchAI

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AIWeb SearchChat AssistantOpenAIGPTRAG

Web app that blends traditional web search with an AI chat assistant. Search, review selected context from results, then ask questions to GPT/Groq/Gemini using that context for grounded answers. Built with Next.js, TypeScript, JavaScript, Convex Database, and Vercel AI SDK. Performs a large amount of scraping/parsing live server-side for enhanced context, with semantic intent observation to return only relevant answers to prevent context pollution.

ComposerAI

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AIEmail ClientLLMProductivityTask AutomationVector Search

AI-native email client. Indexes every message in Qdrant for semantic search (embeddings and BM25/BM42 (RAG) search). Powerful full mailbox search, and automatically writes and generates replies that cite prior conversations, and suggests follow-up tasks from context. Built with Svelte + Vite and Spring Boot.

Professional Experience

  • aVenture2023 - Present
    Founder & CEO
    ·San Francisco, California·aventure.vc
    • Building a research platform with data on venture-backed startups and their investors to help founders and investors make better decisions
    • Backed by Techstars
  • TS Bank2021 - 2022
    President, wealth management division
    ·San Francisco, California / Omaha, Nebraska·tsbank.com
    • Led unit following acquisition/sale of Callahan Financial Planning
  • Callahan Financial Planning2010 - 2022
    Founded and led an SEC-registered investment advisor
    ·San Francisco, California / Omaha, Nebraska·tsbank.com
    • Provided comprehensive financial planning and investment advisory services, including proprietary cloud software for managing complex/nuanced data sets in such relationships
    • Managed $225 million in assets on acquisition
  • Mutual First Federal Credit Union2020 - 2021
    Board member
    ·Omaha, Nebraska·mutualfirst.com
    • Served on the board of directors, including as treasurer, overseeing the strategic direction and financial health of the credit union
    • Primary focus on product differentiation and pricing strategy, asset-liability management strategies, and growth strategy
  • Morningstar2015 - 2019
    Advisor to the executive team
    ·Chicago, Illinois·morningstar.com
    • Provided strategic and specific direction to the executive team on the development of new SaaS offerings for advanced investment research and portfolio management

Education

  • Creighton University2016

    Master of Investment Management & Financial Analysis (MIMFA)

    Omaha, Nebraska

  • Creighton University2016

    Master of Business Administration (MBA)

    Omaha, Nebraska

  • University of Nebraska2011

    BSBA in Corporate Finance, Banking & Financial Markets, Investment Science & Portfolio Management

    Omaha, Nebraska

Selected Programming Coursework

  • Programming Methods - Java2025
    College of San Mateo
  • Object-Oriented Programming - Java2025
    College of San Mateo
  • Python Programming2025
    College of San Mateo
  • Unix & Linux Systems2025
    College of San Mateo
  • Data Structures & Algorithms2025
    College of San Mateo
  • Web Development (JavaScript / TypeScript)2025
    University of California Berkeley
  • Machine Learning for Business with Python2024
    Stanford University
  • Large Language Models for Business with Python2024
    Stanford University
  • User-Centered Design for AI Applications2024
    Stanford University

Certifications & Professional Development

  • Executive Education – Venture Capital Decision Making

    Columbia Business School• 2022• New York, New York

  • Certification in Startup Law & Venture Capital Investing

    University of California Berkeley• 2022• Berkeley, California

  • Chartered Financial Analyst (CFA) Charterholder

    CFA Institute• 2016• Charlottesville, Virginia

  • Certified Financial Planner (CFP) Professional Certification

    CFP Board• 2012• Washington, District of Columbia

Technical Focus

Languages & platforms

  • TypeScript (JavaScript)
  • Java
  • Python
  • SQL
  • PostgreSQL
  • Qdrant

Frameworks & runtimes

  • Next.js
  • Node.js
  • React
  • Svelte
  • Spring Boot
  • Vite
  • Docker

AI systems & data

  • Hybrid search (BM25/BM42 + embeddings)
  • Retrieval-augmented generation
  • LLM tool chaining
  • Vector indexing
  • Self-hosted LLM inference
  • Semantic meaning extraction

Investment, finance, & risk analytics

  • Asset-liability management
  • Quantitative research
  • Factor modeling
  • Portfolio optimization
  • Performance attribution

Last updated: November 11, 2025

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