The Man Behind the Numbers
He keeps a mental model of the five private-market software companies growing more than 30% in any given year. Not as trivia. As a working list. Alex Immerman, now General Partner on the Growth investing team at Andreessen Horowitz, has spent seven years at a16z developing the kind of pattern-matching instincts that only come from watching hundreds of deals up close - and choosing which ones to actually write a check for.
Immerman was elevated to GP in January 2026, joining a16z's growth fund apparatus that now manages over $22 billion across five vehicles. The timing is deliberate. Growth-stage investing has never been harder to navigate: fewer than five public internet software or fintech companies are growing north of 30% in the current environment. That scarcity makes his job simultaneously more competitive and more impactful.
"If you were to scan public internet software, fintech, there are fewer than five companies growing north of 30% this year."- Alex Immerman, a16z General Partner
Before a16z, the path was methodical and deliberately varied. Investment banking at Allen & Company - a boutique that values relationships over volume. Chief of Staff roles at two very different companies: the CFO's office at Facebook during peak scale, and the CEO's office at Gainsight, a smaller enterprise software company where the exposure was operational rather than financial. Then General Atlantic, where he spent years alongside David George investing in and supporting growth-stage technology companies.
That decade-long partnership with George - first at GA, then carried to a16z - is one of the lesser-told stories behind Immerman's trajectory. The firm's growth team was built largely around that chemistry. George describes his colleague simply: "a hustler, in the best way, with great instincts."
Back the Leader. Build the Framework.
There is a sentence Immerman returns to when explaining how he thinks about deals: "In our business it is critical to back the market leader." Not the scrappy challenger. Not the second mover. The leader - or the company most likely to become one. That conviction narrows the funnel and explains a lot about his portfolio.
Waymo was not a consensus bet when a16z backed it. Flock Safety built a nationwide network of license plate readers for law enforcement when "physical world technology" was not yet a category that growth funds cared about. ElevenLabs was a voice AI company before most people could tell AI voices from human ones. These are not accidental investments - they reflect a specific bet on category-defining companies at the intersection of AI, physical infrastructure, and institutions.
Winning platforms capture disproportionate value. Secondary players in the same market often capture almost none.
On AI-native companies specifically, Immerman has developed a distinct framework. Traditional SaaS benchmarks do not apply cleanly to companies where gross margins often start at 0-50% instead of the expected 70%+. His insight - published with Santiago Rodriguez as "Retention Is All You Need" - is that the right unit of measurement for early-stage AI products is not Month 0 retention but Month 3 retention. The first three months are full of tourists. After that, the shape of the retention curve tells you almost everything.
M12/M3 ratio is an early predictor of long-term net dollar retention quality among committed customers. "AI tourists" inflate M0 numbers - the real signal starts at M3.
The prediction markets thesis follows similar logic. His piece on Kalshi - the regulated prediction exchange he backed at Series D and E - argues that entertainment, crypto, and politics show stronger long-term retention than sports. Sports is mass-market acquisition. But the durable platform is one where traders build careers around domain expertise - trading events they understand, not just odds they can find elsewhere.
"Success means these things get boring."
Bloomberg's Michael McDonough on prediction markets, cited by Immerman - drawing parallels to 1970s options market developmentThe Companies He Bet On
From AI voice technology to autonomous vehicles to prediction markets, Immerman's portfolio reads like a map of where technology is colliding with the physical world and institutional systems.
Flock Safety - The Most Underappreciated Tech Platform in America
When Immerman calls Flock Safety "one of the most underappreciated technology platforms in the country," he is making a specific claim - not a branding exercise. Flock builds a nationwide network of license plate readers and safety cameras that help law enforcement agencies identify vehicles linked to crimes and share intelligence across jurisdictions. The result: investigators who used to spend weeks on a case now spend hours.
The number that makes people stop: Flock solves over 2,800 cases every day. That is roughly 15% of reported crime in the United States. For a company most people outside law enforcement have never heard of, the scale is remarkable. This is what Immerman means when he talks about the physical world opportunity - not consumer apps, but infrastructure-level technology that rewires how institutions operate.
"Flock solves over 2,800 cases every day. That's about 15% of reported crime in America."- Alex Immerman on Flock Safety
The Road to General Partner
Built in the Best Rooms
The Hustler with Great Instincts
There is a David George quote that has followed Alex Immerman through his career: "a hustler, in the best way, with great instincts." George worked with Immerman for over a decade - first at General Atlantic, then built a16z's Growth team around that combination. The description has stuck because it captures something real: Immerman moves fast, thinks in frameworks, and builds relationships that last past the initial check.
He grew up in New Jersey and now lives in San Francisco - a standard enough trajectory for tech finance. What's less standard is that he still makes time to ski and snowboard in Park City, Utah, where his parents live. This is not a detail he broadcasts. It is the kind of thing that surfaces when someone asks about a person rather than a resume.
His writing - published through a16z on topics from AI retention benchmarks to prediction market infrastructure - reveals an investor who thinks in second-order effects. Not "what is this company doing" but "what does it mean if this category becomes institutional infrastructure." The prediction markets essay ends with a Bloomberg quote about success making things boring. Immerman finds that compelling, not depressing.
The Playbooks He Publishes
A rare thing in venture: an investor who publishes frameworks that founders actually use. Immerman's a16z essays have become standard-issue reading for growth-stage founders navigating AI retention, prediction markets, and autonomous vehicles.
Watch: Alex Immerman on AI and the Modern CFO
Immerman sits down to discuss how AI is fundamentally changing the role of the Chief Financial Officer - and what that means for the companies building these tools.
The Details That Don't Make the Deck
His LinkedIn handle is just "immerman" - no first name. Seven years of working at one of the world's most visible VC firms will do that.
Graduated summa cum laude from Wharton, then earned his Harvard MBA with distinction. Both the ceiling and the bar were deliberately high.
Grew up in New Jersey. Currently San Francisco. Escapes to Park City, Utah to ski with his parents when the market pauses long enough to allow it.
Worked under the CFO of Facebook and CEO of Gainsight before ever writing a check. He learned what scale looks like from both ends of the org chart.