Alex Hess

Principal Software Engineer · Cloud infrastructure, automation and AI agents

About

I build the automation that runs cloud infrastructure at scale. I’m a principal software engineer at Snowflake, where I designed the workflow automation platform that provisions and manages the infrastructure behind every Snowflake deployment on AWS, Azure and GCP. These days I lead work on AI agents that write and validate infrastructure changes, and on keeping what they know grounded in fact.

Before Snowflake I spent thirteen years as the lead developer of an entire company’s in-house software. In my spare time I build hardware: LED floors, transit gadgets, vending-machine hacks, and a lot of ESPHome firmware. I’ve also been running a large online community site, which I wrote from scratch, since 2002.

Work

Snowflake

Principal Software Engineer, Control Plane · 2023 – present · earlier as Senior Cloud Infrastructure Engineer, Toronto

Every Snowflake region runs on cloud infrastructure that has to be created, changed and checked continuously. I designed and built the workflow automation platform that does this. It became the default way teams across the company automate infrastructure, and I’m the technical lead for the group of about thirteen engineers who build it.

  • A platform other teams own. Teams such as networking, container services and product security write and merge their own automation modules on it, without waiting for central review.
  • Faster, steadier releases. Cut downtime between platform updates from 10 minutes to 10 seconds, cut standby memory use by 75%, and made the UI about 1,000× faster with a module cache.
  • Typed metadata instead of YAML. Co-designed a metadata service that replaced hand-edited YAML files as the source of truth for deployment data and feature flags.
  • AI agents for infrastructure. Built the first prototype of an agent that writes and validates infrastructure changes, a harness that backtests it against work already done, and a knowledge base whose articles are checked claim by claim against their sources.

LiveTechnology

Lead Software Developer, R&D · 2007 – 2020

LiveTechnology ran on software I wrote. Instead of Jira, Google Docs or Confluence, every employee used an in-house suite: project and time tracking, document management, bug tracking with screenshot markup, a client for the company’s object-based database, and a data-driven template engine that generated print and digital ads at every size a client needed. I reported directly to the CEO.

Contract work

BitCine Technologies · Raven Systems · 2020

  • BitCine Technologies. When film festivals moved online during COVID, I built their streaming apps for Android TV, Fire TV (Kotlin) and Samsung Tizen (HTML5/JavaScript), with branded builds for four festivals including Milwaukee Film and Tallgrass Film.
  • Raven Systems. Rewrote the controller for a planetarium-dome lighting system from C++/OpenGL to C#, with a clearer UI, import of existing customer projects, and fixture control over Art-Net.

Builder

Things I've made outside work, mostly at the line between hardware and software.

The LED dance floor lit in a rainbow gradient at HackLab.TO.

LED Dance Floor

2014 – 2017

A 16 × 16 ft interactive floor with 256 tiles and 7,680 RGB LEDs.

Every tile has its own pressure switch. I designed the controller board in EAGLE (85 boards, factory-assembled), wrote the ARM Cortex firmware in C, and drive the floor with Art-Net over Ethernet from control software on a PC.

A weatherproof box with a green button mounted on a Toronto streetcar stop pole.

TransitTunes

A button at a streetcar stop that tells you when the next car is coming.

Press the button and a speaker announces live arrival times from the NextBus API. Built with HackLab.TO; CBC Radio’s Metro Morning interviewed me about it live.

A sheet of acrylic in a laser cutter, cut into a grid of identical parts.

SVG to GCode

Turns vector drawings into laser-cutter toolpaths, with no libraries.

My own SVG parser, renderer and path planner, with tiling, raster fill and multi-sheet splitting. It ran the HackLab.TO laser cutter for years.

A vending machine fitted with a custom card-reader panel and a blue LCD.

PopCard

Tap-to-pay for an ordinary pop machine.

An Arduino with Ethernet, wired into the machine’s bill-acceptor harness, so building tenants could buy drinks with their access cards.

A dish radio and antenna on a wooden mast on an island rooftop.

Long-range wireless links

17 km of 5 GHz radio to a solar-powered island.

Planned and installed point-to-point links: 150 Mbps across open water to a private island in the Bahamas, and 250 Mbps to a home in upstate New York whose only other option was satellite.

ESPHome components

2021 – present

Open-source firmware for card readers and vintage LED signs.

Components that bring odd hardware into Home Assistant: Wiegand card readers, old Alpha and MAX3000 LED signs, a walk/don’t-walk sign. Also a Go bot for planning events on Telegram, and a merged fix to Telegram Desktop.

Community website

2002 – present

A large online community, built from scratch and still running.

Forums, private messaging, a searchable database with maps, and moderation tools, all written from scratch. Tens of thousands of members have contributed millions of posts and photos, and it still runs on servers I maintain.