Hello there! My name is

Darius Cepulis.

I make great web experiences.

About Me

I'm an Experience Engineer at Mux, which means I get to use the web and good design to make the developer experience great, from the top of the marketing funnel to the last page of our docs and everywhere in between.

Fun fact about me, I actually like writing CSS. Weird, huh?

Some Places I've Worked

Experience Engineer
@ Mux

Chicago, IL

February 2022 – Present

  • Working with the coolest team to build our marketing and docs site, and whatever other microsites come up
  • Of course, that means maintaining those sites, too. Digging deep in the weeds to migrate those code bases to Next.js and clean up every last dusty corner.
  • Wearing other hats: writing content, maintaining SDKs, and whatever other technical odds 'n ends pop up where a good web developer could make the developer experience better

Full-Stack Web Developer
@ Microsensor Labs

Chicago, IL

November 2018 – January 2022

  • Worked closely with hardware team and stakeholders to design, develop, and deploy a full-stack data analysis and visualization application for improving hygiene compliance in hospitals, used by dozens of users in a clinical trial setting.
  • Provided input across hardware and software to ensure simple and coherent user interactions and experiences.
  • Established and maintained our corporate visual identity while developing marketing materials and web sites.

Corporate Research Co-Op
@ Bosch

Renningen, Germany

January – August 2017

  • Designed and developed web app suite for large-scale, intuitive sensor data aggregation and analysis.
  • Lived and worked in a diverse, multilingual, international environment.

Innovation Lab Co-Op
@ BMW Manufacturing

Greenville, SC

January – December 2015

  • Worked closely with stakeholders to design, develop, and deploy an iOS app for automobile inspections, saving them over an hour a day.
  • Assisted Deep Learning research efforts by benchmarking clusters and preparing datasets.

Some Things I've Worked On

The hero of the Mux home page. An interactive element cycling through the three Mux product categories: video, player, data.

Mux Marketing Site

  • Tailwind CSS
  • Sanity
  • Mux Video
  • Framer Motion

Collaborating with the best team in the world to push our marketing pages further. Making sure it's speedy, maintainable, search-engine friendly, and just nice to use. Frequently interjecting things like "what do you think of this bezier curve?" and "does it have to be an image? We could make it an interactive element".

I am so stinkin' proud of our recent rebrand.

The Mux Documentation site. An easy to use navigation bar, a search bar, and information delivered both in video and in text.

Mux Documentation Site

  • Tailwind CSS
  • Algolia
  • MDX
  • Mux Video

Developers frequently tell us that our docs are the best part of Mux. Recently overhauled to support a redesign and information re-architecture, as well as push performance with React Server Components. I wrote a blog post about that, by the way!

The Sanibit Dashboard, feturing a line graph of hand hygine compliance over time

Sanibit Web Platform

  • Redis
  • GitHub Actions

A full-stack application, written bottom-to-top, that analyzes millions of data points to help healthcare providers improve their hygiene and reduce hospital-acquired infections. The app provides easy-to-use and comprehensive data visualizations to managers and supervisors so that they can discover trends and take action. At the same time, it gamifies hygiene for individual providers with friendly competition, engaging interactions and animations, and a rewards system.

Other Noteworthy Stuff

A classic Macintosh with some classic 80s typography, proudly introducing The Mux Informational

The Mux Informational

  • styled-jsx
  • Sanity
  • Mux Video
  • Framer Motion

Worked with our top-notch designers on an alarmingly short notice to really go all-in on this incredible vibe. Used the most modern of responsive css, from grid auto-fit to clamp. The best part? They trusted me to make those neat animations.


  • Web Components
  • OSS
  • node

Built alongside @mux/mux-player-react/lazy to give Mux Player a snappy loading experience, particularly in SSR environments like Next.js and SvelteKit. I've got a blog post about that one, too!

The Midwest Microbio home page

Midwest Microbio Site

  • Tailwind
  • Prismic
  • d3-force

A minimal marketing website designed and built for a buddy's budding beer business. Interactive visualizations make visits to the site informative and memorable. Prismic CMS allows easy changes to commonly-updated areas of the site. Formerly Pug, Parcel, and Bootstrap.

The Microsensor Labs home page

Microsensor Labs Site

  • Netlify CMS

A marketing website providing not only information regarding Microsensor Labs' projects, but also a lightweight JAMStack blog and jobs listing built on Netlify and Gatsby.

The home page of the website; a sunset with a city skyline in front of it.

Our Famliy Website

  • Mux Video
  • Sanity

A place for me to put our slideshows so I wouldn't have to bore people in person! Also, a sneaky opportunity to finally write a tribute to the legendary Firewatch parallax effect.

A clock, except instead of hours around the edges, locations like 'Home' and 'Away'

Serverless Weasley Clock

  • Netlify Functions
  • FaunaDB

I've been wanting to build a Weasley Clock for a long time. Some cell phone location data and a Raspberry Pi, and you've got something that seems like magic.

The Sensor Analytics Platform home page, featuring a complex query below and a line graph of its result above

Bosch Sensor Analytics Platform

  • jQuery
  • Node.js
  • InfluxDB

How I started in hardware and accidentally ended up a web developer. A stack of applications providing sensor data storage, real-time monitoring, and historical analysis; all with a modular API.

A website featuring a large table of statistics

Formula Fun!

Some friends started up a betting pool for the 2021 season of Formula One. "Buy" four drivers and win points based on how they do. I wondered if I could beat the game with a neat app…


See so much more, including my graveyard of half-finished projects, on GitHub.

How to Reach Me

Credit Where Credit Is Due

Lesser artists borrow; great artists steal.

I wish I were creative enough to come up with all the cool things I did with this site! Don't get me wrong: nothing here is copy/paste, and I tried to make it my own. But I wouldn't have gotten here without some really great ideas, inspiration, and bug fixes from the following amazing developers:

Content Structure
Thank You Brittany Chiang
Interactive Profile Pic
Thank You Cassie Evans
Bio Length Selection
Thank You Chris Coyier
Thank You Josh W. Comeau
Dark Mode FOUC Solution
Thank You Dan Abramov
Thank You Josh W. Comeau
Mood Board
Thank You Fibbage 3