Jonathan Winer

Jonathan Winer spends most of his days doing something few investors do: exploring. Before Sidewalk Infrastructure Partners, the firm he co-founded and co-runs, commits a dollar, its team maps an entire slice of the physical world - the engineering risk, the policy risk, the contracting risk - into what Winer calls a "digital master plan." Only then does the checkbook come out. "We're not calling investment banks," he has said. "We're fundamentally spending most of our time exploring areas of infrastructure."

That approach has produced a firm unlike a conventional fund. SIP, backed by Alphabet, the Ontario Teachers' Pension Plan and StepStone, has raised close to $1 billion and used it not just to buy stakes but to build companies. Two of them define the moment. Renew Home, formed in 2024 by combining Google's Nest Renew business with the demand-response company OhmConnect, now orchestrates a virtual power plant of roughly one gigawatt - homes and thermostats acting in concert to shift electricity when the grid is stressed. And Verrus, unveiled in 2025 after eighteen months in stealth, is building data centers designed to do something counterintuitive: give power back.

The Verrus idea captures how Winer thinks. As artificial intelligence sends electricity demand soaring, most developers treat a data center as a giant, permanent draw on the grid. Winer wants his to behave like an asset that helps balance it. He describes the design as "a critical energy microgrid, for lack of a better term, with a battery at its core and a software layer that orchestrates the allocation of power." When the grid is congested, the facility can island itself and lean on its batteries; when power is abundant, it runs hard. "We're utilizing the power more efficiently," he says. "We're essentially spinning up compute when we need it compared to the power."

His read on the industry is blunt: "Today's data center developers are essentially real estate developers, but in the future they'll need to be sophisticated asset managers as well." First facilities are targeted for late 2026.

The timing is not accidental. Regulators are warming to the idea of treating large, flexible loads as grid resources rather than pure burdens. As Winer puts it, "FERC and other public utility commissions are much more receptive to providing interconnection for resources, rather than just load." A data center that can shed or shift demand on command is easier to plug in - and more valuable to a utility - than one that only takes. That regulatory shift is exactly the kind of opening SIP's thematic research is built to spot before the rest of the market does.

Winer's central insight has a name he uses often: the "missing middle." Traditional infrastructure investors like proven technology and predictable cash flows; they shy away from anything that smells like a science experiment. Venture capitalists love technology risk but recoil from the heavy, slow capital that roads, grids and pipes demand. In between sits a large territory almost no one is built to fund - the place where a promising technology meets a real, physical asset. SIP was designed to live there.

He arrived at that thesis the hard way. At Alphabet's Sidewalk Labs, where Winer served as head of investments for the company's urban innovation platform, he worked on a sprawling, multi-decade plan to redevelop Toronto's Portlands waterfront. The project, later paused during the pandemic, forced a realization: inside it were really three different businesses - urban innovation, real estate, and the enabling infrastructure underneath. Separating them out revealed the gap that would become SIP's reason to exist.

What makes the missing middle so stubborn is that it demands two temperaments that rarely live in the same firm. You need the patience of an infrastructure investor, who thinks in decades and understands that a grid interconnection or a water permit is not a software sprint. And you need the nerve of a venture investor, who can underwrite a technology that has never been deployed at scale. SIP's answer is process. Its "digital master plans" treat an entire sector - power, roads, water, digital connectivity - as a system to be modeled, so that when technology risk and capital risk collide, the firm has already priced both. It is why Winer describes the work less as deal-making and more as sustained inquiry.

Winer was born in Boston and raised in suburban Arizona, in a household where academics came first. He went to Yale intending to study philosophy and, eventually, to get a graduate degree in it. Then, at nineteen, a roommate proposed dropping out to start a software company. Winer did not say yes. He said he would go only if five conditions were met - an anchor investor, a first customer, a credible path to a working product, and more. A week later, the roommate came back having satisfied all five. Winer left to co-found a natural language processing startup built on early neural network technology, later returning to Yale to complete degrees in philosophy and computer science.

The company found real traction - an anchor customer, a path toward breakeven - before the dot-com crash of 2001 dried up funding and it sold in a modest, acqui-hire-style deal. Winer landed at the D. E. Shaw group, joining the founding group that built the quantitative firm's private equity business across venture capital, growth equity and structured finance. It was, he says, an apprenticeship that permanently shaped how he sees risk: "there are very different ways to do this, and you will be forever shaped in how you see the world."

At D. E. Shaw, Winer noticed a contrast that would set the direction of his career. The United States was a power-surplus country where renewables needed subsidies to compete. India was the opposite - hundreds of millions of people without reliable electricity, a place where distributed clean energy could pencil out on its own economics. In 2009 he founded Nereus, a private equity fund investing in alternative energy infrastructure across Asia, and ran it for nearly a decade.

A friend's introduction to Larry Page pulled him toward cities. Page's habit of reasoning from first principles - asking, for instance, "what if you had an AV-only environment?" as a way to rethink streets, logistics and transit from scratch - left a mark. Winer joined the early Sidewalk Labs team, and when the Toronto project revealed the missing middle, he and his co-founders spun out SIP in 2019.

The Nereus years left a technical inheritance he still draws on. Project finance - the discipline of funding a physical asset against the cash flows it will one day produce - is the connective tissue between a clever technology and a bankable business. Many of the founders SIP works with are brilliant on the engineering and naive on the financing; Winer's teams supply the second half. That combination is why SIP tends to take ownership rather than passive stakes. Renew Home and Verrus are not line items in a portfolio. They are operating companies the firm helped assemble, capitalize and staff.

That is the throughline of everything Winer builds. Where an old operator runs a basic toll road, he imagines a technology-enabled one. Where a utility fires up a peaker plant, he points to a virtual power plant assembled from thousands of homes. Where a data center simply consumes, Verrus negotiates with the grid. He borrows freely - technology-risk discipline from Alphabet's "other bets," project finance from his renewable-energy years, and the innovation appetite of venture capital - and stitches them into a single method.

His advice to younger founders reflects the same balance between conviction and flexibility. Choose your earliest board members and senior hires with great care, he says - "be very very thoughtful about who those folks are" - and anchor to their wisdom, while making sure you remain "the most nimble" person in the room. Experience, in his telling, is a compass, not an anchor. It is a fitting philosophy for someone who set five conditions before betting on himself, and has been recalculating the odds on the physical world ever since.