Daniel Krol

Senior Software Developer

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Clean code, Clean data, Clear team communication.

Work History

Part-time Software Engineer
Oct 2021-Current, Manchester, NH Develop Non-custodial wallet sync service Created an open source web service, written in golang, to synchronize a user's LBRY cryptocurrency wallet across multiple devices without giving the clients access to the user's secrets. Account for encryption of the wallet and account access using the same password.
Various Contracting/Freelancing
Apr 2020-Current See Contracting Below
Platform Engineer
Nov 2016-Sept 2019, San Francisco, CA Member of API Services team Development/bug fixes in Go and Node.js services for content recommendation application. Interfaced with recommendation engine, and coordinated with Recommendation Service team on architecture decisions. Encouraged code organization and leveraging type system where possible. New version of recommended content categorization Coordinated with Recommendation Service team to roll out new version of topic categorization system for recommended content. Included establishing initial set of topics and creating a plan to roll out future topics. Feedback sent to Recommendation Service Added hooks to user events on recommended content which sent feedback with context back to the Recommendation Service.
Basis (an Intel company)
Backend Engineer
Apr 2015-Nov 2016, San Francisco, CA Development/maintenance for API service On API team for fitness tracking watch. Features, bug fixes, deployment, and configuration changes. Developed in Python, deployed using SaltStack. Transitioning between two sleep data streams Transitioning between two versions of the user's sleep data streams, while avoiding interruptions in both individual sleep events and daily aggregates. APNS (Apple push notifications) Configuration Debugging problems with APNS service and Python library. Configuration changes to APNS deployment on cluster, including installing new certs.
Brilliant (formerly Alltuition)
Senior Engineer
Jul 2011-Nov 2014, Chicago, IL / San Francisco, CA Ajax View framework (brilliant.org) Implemented a view framework on top of Django. Facilitated reuse of code between partial and full page loads. Transparent fallback to non-javascript (targeted users with potentially old browsers). Practice Section (brilliant.org) Implemented the backend of the initial version of the Practice Section on brilliant.org. FeeFighters Samurai Python API library (alltuition.com) Implemented initial Python client library for the FeeFighters Samurai API. My contributions are best seen here: https://git.io/vgH2u Analytics Integration (brilliant.org) Initial analytics data schema. Added ability to trigger analytics events from Python, which ran as a background task, or rendered in the browser as JavaScript calls to various 3rd party services. Improvements to loan consolidation rate prediction system (alltuition.com) Conducted Mechanical Turk based research project (alltuition.com)
Oracle (formerly Stellent)
Software Engineer
Feb 2006-Sep 2010, Chicago IL Spreadsheet file parsers for Outside In Bug fixes, optimization, general maintenance, and feature implementation, in C. Responded to customer support requests, worked with display engine team, focused on maintaining legacy functionality.
ElectionBettingOdds.com - October 2020-October 2022 Add features to static site generator, Aggregating data from from multiple prediction markets Sandstorm.io (open source project) - Oct 2021-Mar 2022 Upgrade the Sandstorm.io package for Etherpad-lite Etherpad-lite (open source project) - April 2020-July 2020 Various bug fixes and features developed for Etherpad, a self-hosted collaborative word processor Datamaglia - Dec 2014-Feb 2015 Bare-bones user dashboard in Django for datamaglia.com Voyager Tech - May 2011-Jul 2011 Django admin customization for memprotein.org Shelfworthy - Apr 2015-Oct 2010 Django development for shelfworthy.com Reuseit - Nov 2009-Dec 2009 / Feb 2011-Jul 2011 PHP/SQL development, feature/bug fixes for site, store and shipping systems Brilliant - October 2020-July 2021 Planning and writing interactive online computer science course material


Feed Getter:
github.com/orblivion/feedGetter An RSS aggregator in Haskell.
Haskell Synth:
github.com/orblivion/Haskell-Synth A sound and music synthesizer in Haskell.
Argument Clinic
An experimental debate site (now defunct). Created with Django. Attempted to structure debates with subdebate and definition constructs. Had few, but enthusiastic users.


  1. Languages
  2. Python
  3. Go
  4. JavaScript
  5. Haskell
  6. Tools
  7. Django
  8. PostgreSQL
  9. Angular
  10. Ansible
  11. Docker
  12. AWS
  13. Platforms
  14. Ubuntu/Debian
  15. QubesOS
  16. OSX
  17. Other
  18. Test Driven Development
  19. Functional Programming
  20. WebRTC
  21. Blockchain


Illinois Institute Of Technology
B.S., Computer Engineering
2001-2005, Chicago, IL
Miscellaneous Courses
Coursera: Functional Programming Principles in Scala
Course Record: www.coursera.org/records/yjD8PGuY9cGQpE5g
Erlang Camp 2014
A weekend-long crash course in Erlang and OTP, which took place in Austin Texas


  1. Interests/Activities
  2. Personal Programming Projects
  3. Collecting Old Video Games
  4. Juggling
  5. Biking
  6. Free and Open Source Software
  7. OpenStreetMap Editing

Dec 01 2022 -- Daniel Krol -- dan@danielkrol.com