When Cloudflare acquired Eager in December 2016, the announcement blog post noted that Zack Bloom and co-founder Adam Schwartz had "impressive experience building the very type of tools they are looking to help users install," and that their combined GitHub projects had "more than 60,000 stars." In Silicon Valley terms, that was high praise delivered in the driest possible register. It also set the template for how Bloom operates: build something useful, earn credibility through the work itself, and scale when the timing is right.
The Cloudflare years were formative in ways that look clearer in retrospect. Bloom went from engineering manager to product director during the period when Cloudflare Workers became the defining edge compute platform. Workers did not just run JavaScript closer to users - it changed what developers thought was possible at the edge. Understanding how to evangelize an unfamiliar infrastructure category to skeptical buyers, persuade engineers to build on a new platform, and make pricing accessible enough to drive adoption - all of that translated when Bloom left to build Heirloom.
The Heirloom Bet
In September 2020, Bloom co-founded Heirloom Carbon Technologies with Shashank Samala - who had previously founded Tempo Automation and served as Entrepreneur in Residence at Carbon180 - and Noah McQueen, a chemical engineer with deep expertise in carbon mineralization from the Colorado School of Mines and Worcester Polytechnic Institute. The founding team's unusual combination of skills - software, industrial manufacturing, and geochemistry - was not accidental.
Heirloom's core insight was that the existing approach to direct air capture was engineering-forward in the wrong direction. Most DAC companies were building highly engineered sorbent systems that cost hundreds or thousands of dollars per ton to operate. Heirloom looked at the periodic table instead of the chemical catalogue and found limestone: calcium carbonate, one of the most abundant minerals on Earth, already doing exactly the job they needed. The cost of the sorbent material in Heirloom's process is less than 1% of the cost of engineered alternatives.
The hard part was speed. Limestone naturally re-absorbs CO2 from the atmosphere - but over years, not days. Heirloom's innovation was applying industrial heat (from a renewable-powered kiln) to drive off the CO2, converting limestone to calcium oxide, then hydrating it to calcium hydroxide, spreading it on vertically stacked trays where it rapidly pulls CO2 back from the surrounding air. The geological process that normally unfolds over millennia now runs in days. The system is modular: the same tray-stacking approach that works at a small facility works at a large one.
First Facility, First History
In November 2023, Heirloom opened the doors to America's first commercial direct air capture facility in Tracy, California. The facility captures 1,000 tons of CO2 annually - small by industrial standards, but a proof point that required years of scientific validation, permitting, construction, and fundraising. The CO2 captured there goes to early buyers: Microsoft, Stripe, Shopify, and Klarna, among others. Some is stored underground; some is mineralised into concrete through a partnership with CarbonCure Technologies.
The Louisiana projects represent the next scale-up: two DAC facilities with a combined annual capacity of nearly 320,000 tons, one of which is expected to come online in 2026. These facilities will be powered by 100% renewable energy, built with strong labor protections, and structured to create high-paying jobs in communities that have historically borne the burden of heavy industry without the benefits.
The Infrastructure Parallel
There is a through-line in Bloom's career that is easier to see from a distance. At Eager, he was solving a distribution problem: how do you get useful software in front of people who cannot install it themselves? At Cloudflare, he was solving a scale problem: how do you run compute billions of times a day at low latency and reasonable cost? At Heirloom, he is solving both simultaneously - and the units are tons of CO2, not API calls. The modular, low-cost, geographically flexible approach to carbon removal looks a lot like the mental model you would develop after years inside the CDN industry.
Bloom lives in Austin, Texas, now - a long way from West Bloomfield, and further still from San Francisco's climate-tech scene, even as he remains embedded in it. He plays drums, photographs things, and reportedly still commands the respect of carnivores at any company barbecue. The beginner's luck superpower, self-identified in a HubSpot blog post from 2012, seems to have held up.
