Hi, I'm James!

James Seppi

I am a software developer in Austin, Texas, currently on the Design Team at Mapbox. I code primarily for the web using JavaScript and Python, but dabble in other languages.

Prior to Mapbox, I worked at 18F, where I was the technical lead on a number of projects that help transform the way the federal government delivers digital services.

Before 18F, I was the lead software developer at the Texas Natural Resources Information System (TNRIS), where I helped transition the group to using and creating open-source software, and to using cloud-based infrastructure.

Nearly all of my code is open source, and I enjoy contributing to other open source projects.

In my free time, I'm a beginner fiddle player, an aspirational rock climber, an enthusiastic traveler, and a decent home cook and beer brewer.

Other interesting tidbits:

  • I'm the program chair for FOSS4G-NA 2018.
  • My wife and I spent six months living at 10,000 feet in Huaraz, Peru, while working on an Engineers Without Borders project to help local communities adapt to climate change.
  • I have a Master of Engineering degree in Environmental and Water Resources Engineering from the University of Texas.
  • My wife and I swept the awards at the 24th Annual Lone Star Vegetarian Chili Cook-Off.
  • As an undergraduate I studied abroad in Hangzhou, China, and I have a Bachelor of Arts degree in Chinese (but I'm extremely out of practice).

Projects & Activities

Federalist | 18F

Federalist is a static site platform for compliantly hosting federal web sites. It greatly reduces the arduous compliance burden of federal offices that want to launch web sites, which saves a large amount of staff time and resources for those offices. Federalist hosts over 100 sites and completes over 1,000 builds per week.
I am currently the engineering lead on this project, building upon the great work of previous 18F developers.

CALC | 18F

CALC is a web-based tool to help for researching awarded labor rates of federal contracts, with the goal of helping contracting officers better negotiate new rates. I was part of a team that added new data ingestion features to CALC.
In addition to coding, I also participated in user research sessions and worked through the federal compliance process necessary to get and keep CALC online.

2017 Interactive State Water Plan | TNRIS

The 2017 Interactive State Water Plan (ISWP 2017) is a web application for the public and planners to explore the data of the 2017 Texas State Water Plan. It was the first time the official State Water Plan of Texas had an online tool as part of its statutorily-mandated content.
I was the primary developer of the ISWP 2017 when I was at TNRIS, and staff who came after me have continued to improve its functionality.


The Geospatial Emergency Management Support System 2.0 (GEMSS2) is a web application for use by the public and state agencies to view a variety of geospatial data layers in a single web map. GEMSS2 was used at the Texas State Operations Center during the response to severe floods in March 2016.
I was the primary developer of GEMSS2.

2012 Interactive State Water Plan | TNRIS

Like the ISWP 2017, the 2012 Interactive State Water Plan is a web application for exploring data of the 2012 Texas State Water plan. It was launched a few years after the paper-based water plan, and was the first time Texas State Water Plan data was put online in an interactive fashion.
I was the primary developer and designer of the ISWP 2012 and worked closely with water planning staff and data analysts.


Maptime is a beginner-friendly gathering to teach each other about mapping and cartographic concepts, often as they relate to maps on the internet. As a founder and co-organizer of MaptimeATX, the Austin chapter of Maptime, I've led several workshops and given talks on topics like Leaflet, TurfJS, and Carto(DB).


If you see something incorrect, or that could be done better, or that just rubs you the wrong way, please let me know!