David Blackman

Geospatial and search expert with high EQ

I started my career on Google Maps, working on the coarse geocoder and search mixer.

At Foursquare I worked on many projects, primarily geocoding, the venues database + tooling, events and superuser tools. While there I built an opensource geocoder called twofishes, and commissioned an open source map boundary dataset called Quattroshapes that became the basis for mapzen's Who's On First dataset.

At Twitter I migrated the geospatial pipeline from a snapshotted postgres database to a reproducible m…

David Blackman


  • Notion


    Senior Staff SWE / NYC Site Lead

    Jan 2021 - Jun 2023

    Building the next generation all-in-one workspace / knowledge management tool / 1970s back to the future hypertext platform

    • Built numerous internal trust & safety / spam tools, maintained and documented internal administrator tooling
    • Lead a team of engineers in developing two week formal onboarding curriculum, built the first codelab
    • Split notion's public content onto a separate domain for increased resilience
    • Decreased search latency by over 50%, increased relevancy by over 10%
    • Oversaw implementation of first machine learning model in the product (search ranker)
    • Implemented user recommendation model in the product (used by both user search and document search ranking)
    • Implemented engineering workflow / developer-experience tooling
    • Maintained notion internal developer CLI
    • Site lead: Grew NYC from no office to 150+ people in an office in Soho. Implemented NYC onboarding, site updates, offsites and lunch-and-learns,
    • Migrated elasticsearch from AWS managed to self-hosted terraform for cost savings, architecture flexibility & performance improvements
    • Implemented observability dashboards and tooling for search indexing & serving
    • Improved korean, english and japanese stemming in document search
    • Created search experimentation framework
    • Created search backend routing framework
    • Implemented comments sidebar with improved unread comment tracking
  • Radar


    Senior Staff SWE / Engineering Manager

    Dec 2019 - Jan 2021

    Developer-friendly, privacy-first geofencing and geocoding that helps product and growth teams build amazing location-based app experiences. Radar.io is a tool in the Mapping APIs category of a tech stack.

    • Implemented significant improvements to internal developer tooling & testing
    • Lead effort to roll out a full suite of geo APIs mainly from open source efforts
    • Evaluated multiple open source routing engines, built production/deployment tooling around two of them
    • Integrated new source of geographic data across multiple services
    • Made contributions back to pelias open source geocoder
  • Contract Development

    Software Engineer

    May 2019 - Jan 2020

    • Fable: Built initial backend for book club reading app, transitioned project to full time developer.
    • Meta: Took over in progress social network + marketplace app from a consulting firm. Rebuilt site with industry best practices + much larger feature set.
    • A Little Drive: Built proof of concept for a new kind of list building application, billed as "wirecutter for everyone." https://www.mixlet.com/
  • Art Sabbatical

    Art Sabbatical

    Creative Technologist

    Feb 2019 - Jul 2019

    Exploring the intersection of generative art, immersive experiences, connection and physical accessories.

    • Assemble: an immersive theater piece set in the Red Hook IKEA https://blackmad.com/digital-projects/assemble/ - featured in No Proscenium, Time Out and Gothamist
    • What is my purpose? an anonymous postcard app http://purpose.blackmad.com
    • Blackmadeco: generative art patterns on custom fit leather accessories http://gen1-alpha.blackmade.co/
    • Dispatches From Yesterday's Future - expo/react-native app in Apple app store to share feelings & memories from quarantine - https://apps.apple.com/us/app/yesterdays-future/id1507282393
    • ~ secret immersive temporary covid-19 virtual art project ~
  • Twitter


    NYC Engineering Site Lead

    Jan 2017 - Jan 2019

    • Lead growth of NYC engineering from ~40 to ~90 people
    • Started site-wide new hire orientation
    • Met with new hires & coordinated first day with manager
  • Twitter


    Staff Software Engineer / Engineering Manager

    Dec 2014 - Jan 2019

    It's What's Happening.

    • Oversaw development of Twitter Moments feature from initial conception to launch to unification into Events experience
    • Managed a team of 20 backend & frontend engineers across two offices and multiple remote locations
    • Launched v1 in a tight six month timeframe, followed by rapid iteration
    • Set a model within Twitter for speed & quality of product delivery and for team cohesion
    • Outsourced & oversaw development of internal editorial tools by a third party development firm
    • Worked with a team of editors & curators to build policy and tooling for human curated content on Twitter
    • Launched in 15+ countries. Saw continuous growth of usage and stickiness over 2+ years
    • Organized efforts into multiple sub-teams with multiple PMs and TLs, lead sprint planning and retros
  • Foursquare


    Staff SWE / Engineering Manager

    Aug 2010 - Dec 2014

    A social network for places - to record visits and recommend real world places to you and your friends.

    • Oversaw the development of Foursquare's venue database and tooling
    • Built out geographic infrastructure, including the open source coarse geocoder twofishes, funding Quattroshapes - an open source administrative boundary compilation, and signing a deal with a third party fine geocoder
    • Wrote or oversaw almost all of the crowd sourced venue editing tools in use by Foursquare, including the launch of a mobile editing webview in use by the client apps
    • Added hours, attributes (good for groups / delivery / etc) and local name translations to venue database capabilities
    • Expanded category hierarchy by 2x, worked with external icon illustrator
    • Launched event checkins, which involved matching venues with multiple external event providers, deduplicating venues across multiple providers
    • Built numerous internal tools including what became s2map.com as well as the venue shape visualization seen in most public presentations
    • Managed a team of 5 people owning all of the venues, events, geocoding, tooling and superuser infrastructure
  • Google


    Senior Engineer

    Aug 2006 - Aug 2010

    • Worked on geocoding and local search

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