Stephen Martin

Built teams for startups and big tech. 20+ years eng experience.

I am a seasoned technology leader with over 20 years of experience in building and scaling high-performance teams. I've worked at industry giants like CashApp (Block), Amazon, and Twitter, as well as numerous startups, honing my skills in solving complex technical problems and driving innovation.

Stephen Martin



  • Cash App

    Cash App

    Director of Engineering

    Apr 2021 - Nov 2023

    Cash App, developed by Square, Inc. (now Block, Inc.), is a mobile payment service launched in 2013. Headquartered in San Francisco, California, Cash App allows users to send and receive money instantly, making peer-to-peer financial transactions simple and convenient. In addition to money transfers, the app offers features such as direct deposit, the ability to buy and sell Bitcoin, and a Cash Card—a customizable debit card linked to a user's Cash App balance. With an intuitive interface and a growing suite of financial tools, Cash App aims to democratize access to financial services, making banking and investing accessible to a broad audience. Known for its ease of use and innovative features, Cash App continues to expand its footprint in the digital finance space.

    • Led monolith decomposition, improved developer velocity, delivered Cash App localization, scaled teams.
  • Amazon


    Engineering Manager

    Feb 2017 - Nov 2020, Inc. is a global e-commerce and technology giant founded by Jeff Bezos in 1994. Headquartered in Seattle, Washington, Amazon started as an online bookstore and has since evolved into the world's largest online retailer, offering a vast array of products including electronics, apparel, and groceries. The company is also a leader in cloud computing through its Amazon Web Services (AWS) division, which provides scalable and cost-effective cloud solutions to businesses and governments worldwide. Additionally, Amazon has expanded into entertainment with Amazon Prime Video, and artificial intelligence with its Alexa-enabled devices. Known for its customer-centric approach, innovative technologies, and extensive logistics network, Amazon continues to redefine online shopping and digital services globally.

    • Scaled NYC teams, led ML, delivered $50M revenue.
  • Twitter


    Senior Software Engineering Manager

    Apr 2013 - Feb 2017

    Twitter, Inc. is a global social media platform founded in 2006 by Jack Dorsey, Noah Glass, Biz Stone, and Evan Williams. Headquartered in San Francisco, California, Twitter enables users to post and interact with messages known as tweets, which are limited to 280 characters. The platform has become a vital tool for real-time communication, allowing individuals, businesses, and organizations to share news, opinions, and multimedia content instantly. With its hashtag feature, Twitter helps users discover trending topics and join global conversations. The platform is widely used for networking, marketing, customer service, and social activism. Known for its influence on public discourse and its role in shaping modern communication, Twitter continues to evolve, offering new features like Spaces for live audio conversations and Fleets for temporary content.

    • Managed 25 critical Twitter apps, scaled team to 21, ensured high uptime.

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