Open-plan offices offer few pleasures; one of them is snooping on other people’s browsing habits. When, years ago, I began working for tech companies in San Francisco, I noticed that my co-workers were always scrolling through a beige, text-only Web site that resembled a nineteen-nineties Internet forum. They were reading Hacker News—a link aggregator and message board that is something of a Silicon Valley institution. Technologists in Silicon Valley assume familiarity with Hacker News, just as New Yorkers do with the New York Post and the New York Times. For some, it’s the first Web site they pull up in the morning; it captures the mix of technical obsession, business ambition, and aspirational curiosity that’s typical of the Valley. On any given day, its top links might include a Medium post about technical hiring; a 1997 article from Outside magazine about freezing to death; an open-source virtual private network hosted on GitHub; an academic paper, from 2006, about compiler construction; an announcement from Facebook’s corporate communications team; a personal blog post about Linux kernels, and another about selling Vidalia onions on the Internet. Nearly all the software engineers I know check it religiously. Not one of them has a neutral opinion about it.

Like many of the software products that have shaped the Valley, Hacker News began as a side project. In 2007, the venture capitalist Paul Graham, who was then the president of the startup accelerator Y Combinator—an early investor in Dropbox, Stripe, Reddit, Twitch, and other companies—built the site as a way to experiment with Arc, a new programming language that he was co-authoring. Originally, Graham named the site Startup News. He hoped that it would serve as a new home for the startup founders and “would-be founders” who had once gathered on Reddit, before that site grew too popular to feel like a community. Among other benefits, he imagined that Startup News might help him find worthy entrepreneurs. (“There are a number of Reddit users that I know only by their usernames, but I know must be smart from the things they’ve written,” he explained, in his launch announcement. “We’re counting on the same phenomenon to help us decide who to fund.”) Within a few months, though, Graham found that startup-centric conversation had its limits. He renamed the site Hacker News, and expanded its focus to include “anything that good hackers would find interesting . . . anything that gratifies one’s intellectual curiosity.” (Hacker News is still owned by Y Combinator.)

The site was intentionally simple. It offered a dynamic list of links, submitted by users, each of which could be expanded into its own unique comment thread. Readers could upvote or downvote links and comments, and the top thirty links would be featured on the front page. The guidelines specified that most non-tech-related news—political news, in particular—was off topic. Users discussed the merits of relational databases, the complexities of co-founder relationships, and the pros and cons of dropping out of college. They exchanged screenshots of their work environments and compared their results on a “nerd quiz” that asked them to name a programming language for every letter of the alphabet. They commented on Graham’s essays about programming and entrepreneurship—“Like chess or painting or writing novels,” he wrote, “making money is a very specialized skill”—and shared advice on how to get into Y Combinator.

At first, the site attracted about sixteen hundred daily visitors, and Graham moderated and maintained it himself. Today, around five million people read Hacker News each month, and it’s grown more difficult to moderate. The technical discussions remain varied and can be insightful. But social, cultural, and political conversations, which, despite the guidelines, have proliferated, tend to devolve. A recent comment thread about a Times article, “YouTube to Remove Thousands of Videos Pushing Extreme Views,” yielded a response likening journalism and propaganda; a muddled juxtaposition of pornography and Holocaust denial; a vague side conversation about the average I.Q. of Hacker News commenters; and confused analogies between white supremacists and Black Lives Matter activists. In April, when a story about Katie Bouman, an M.I.T. researcher who helped develop a technology that captured the first photo of a black hole, rose to the front page, users combed through her code on GitHub in an effort to undermine the weight of her contributions.

The site’s now characteristic tone of performative erudition—hyperrational, dispassionate, contrarian, authoritative—often masks a deeper recklessness. Ill-advised citations proliferate; thought experiments abound; humane arguments are dismissed as emotional or irrational. Logic, applied narrowly, is used to justify broad moral positions. The most admired arguments are made with data, but the origins, veracity, and malleability of those data tend to be ancillary concerns. The message-board intellectualism that might once have impressed V.C. observers like Graham has developed into an intellectual style all its own. Hacker News readers who visit the site to learn how engineers and entrepreneurs talk, and what they talk about, can find themselves immersed in conversations that resemble the output of duelling Markov bots trained on libertarian economics blogs, “The Tim Ferriss Show,” and the work of Yuval Noah Harari.

People have been trying to outsmart one another on Internet forums for as long as there have been Internet forums. Still, Hacker News has an unusually wide influence. Landing a blog post or personal project on the front page is a badge of honor for many technologists, and the site has become a regional export: ninety per cent of its traffic comes from outside the Bay Area, and a third of its users are in Europe. The site is now a portal to tech culture for millions of people. At the same time, it has become a punch line and a punching bag for tech workers and engineers who see it as a locus of hubris, myopia, and exclusivity. A word that comes up frequently among its critics is “toxic.”

Picturing the moderators responsible for steering conversation on Hacker News, I imagined a team of men who proudly self-identify as neoliberals and are active in the effective-altruism movement. (I assumed they’d be white men; it never occurred to me that women, or people of color, could be behind the site.) Meeting them, I feared, would be like participating in a live-action comment thread about the merits of Amazon Web Services or whether women should be referred to as “females.” “Debate us!” I imagined them saying, in unison, from their Aeron chairs.

The site’s real-life moderators are Daniel Gackle and Scott Bell, two wildly polite old friends. On Facebook and YouTube, moderation is often done reactively and anonymously, by teams of overworked contractors; on Reddit, teams of employees purge whole user communities like surgeons removing tumors. Gackle and Bell, by contrast, practice a personal, focussed, and slow approach to moderation, which they see as a conversational act. They treat their community like an encounter group or Esalen workshop; often, they correspond with individual Hacker News readers over e-mail, coaching and encouraging them in long, heartfelt exchanges.

Gackle and Bell met in Calgary, in the early two-thousands, at a local user group for the rarefied programming language Lisp. (Arc, the language in which Hacker News is written, is a descendant of it.) Gackle, whose name is pronounced “Gack-lee” and who declined to share his age, is a muscular, bald, and loquacious father of two and a devoted fan of the Canadian sketch-comedy show “The Kids in the Hall.” Bell, who is thirty-four, is willowy and soft-spoken, with closely buzzed hair and tattoos that peek out from beneath his cardigans. The two often finish each other’s sentences; they sometimes dress, accidentally, in matching outfits. (Bell attributes this to office-wide “sartorial mimetics.”) Online and in person, Gackle is chatty, Bell reserved. They are reluctant, protective spokespeople. Pressed to describe Hacker News, they do so by means of extravagant, sometimes tender metaphors: the site is a “social ecosystem,” a “hall of mirrors,” a “public park or garden,” a “fractal tree.”