Harry
Zhang

The FTP Folder That Launched a $100M Company

At Microsoft, Harry Zhang managed direct mail campaigns for Office products - Project and Visio - and he remembers exactly what that looked like: an entire team of people manually dropping files into an FTP folder to trigger print runs. This was not some legacy startup. This was one of the most technically advanced companies on Earth. And it was using a filing cabinet metaphor to send marketing materials through the post.

That specific, mundane absurdity became the premise for Lob. In 2013, Zhang and co-founder Leore Avidar pitched Y Combinator with a three-word thesis: Stripe for printing. They got in. Lob was born.

The early version of the company had a charmingly unscalable backend: Zhang and Avidar printing and mailing documents themselves from a home printer to fulfill customer orders while building the actual platform in parallel. It is the kind of founding story that sounds quaint until you realize it generated enough early revenue to prove the market and enough momentum to raise $2.4 million in seed funding by November 2013.

The Idea on the Drive Home

The founding conversation happened on a car ride back from a ski trip. Not at a hackathon, not in a Stanford dorm, not over a whiteboard covered in market-size calculations. Just Zhang and Avidar, driving, talking about why a process as old as the postal service had never been properly automated.

The insight was structural: every other transactional system had been API-fied. Payments had Stripe. Email had SendGrid. SMS had Twilio. But physical mail - which enterprises, financial institutions, healthcare companies, and retailers still sent billions of pieces of each year - remained entirely manual. You called a print vendor, you uploaded files to servers, you waited weeks, you had no tracking, no personalization at scale, no feedback loop.

Zhang's experience at Microsoft was not an anomaly. It was the industry standard. That was the opportunity.

Building the First API by Hand

Zhang was not just a co-founder who managed spreadsheets. He built Lob's first APIs himself. The technical foundation was his work - the same instinct that drove him to look at the FTP folder problem and think "this should be a POST request, not a phone call." His dual background in Informatics and Business from Michigan's Ross School meant he could bridge the gap that most enterprise software companies fumble: building for developers while selling to businesses.

Lob went through Y Combinator's Summer 2013 batch alongside what would become a generation of defining developer-tools companies. The YC framing - solve a real problem, talk to users, ship fast - fit perfectly. The problem was real (Zhang had lived it). The users were accessible (any developer building software for businesses that sent mail). And shipping was the job.

From Home Printer to Half of America's Mailboxes

Lob's growth chart traces a familiar SaaS arc but with an unusual protagonist: the United States Postal Service as an infrastructure layer. By the time the company raised its $50 million Series C in February 2021 - led by Y Combinator's Continuity Fund - it had built a platform that enterprises across financial services, healthcare, retail, e-commerce, and nonprofits relied on to automate millions of mail pieces.

The numbers that followed were not incremental. In April 2023, Lob announced $100 million in annual recurring revenue with 40% year-over-year growth. The platform serves 12,000+ businesses. Its network of print partners can reach a mailbox in one of every two U.S. households. What Zhang and Avidar had started by hand-printing letters in 2013 was now a critical piece of infrastructure for how American companies communicate with their customers in the physical world.

What Lob Actually Does

Strip away the positioning and Lob is infrastructure. A developer at a bank writes code that says: send this letter to this address, include this content, deliver by this date. Lob's API handles the rest - routing to the optimal print partner in its network, managing production, tracking delivery, verifying addresses before a single sheet of paper moves. The Address Verification API, launched with the Series B in 2015, became its own product: a way for businesses to clean customer databases before the mail even gets sent.

The business case is clear for any company spending on direct mail at scale. Banks send account statements. Insurance companies send policy renewals. Retailers send promotional catalogs. All of them were doing it with a mix of vendor relationships, manual uploads, and zero real-time insight. Lob gave them the same operational visibility they expected from their digital channels.

Zhang's original framing - that this should be as easy as calling an API - turned out to be exactly right. The companies with the highest volumes were not startups. They were enterprises. And enterprises would pay for a system that replaced an army of FTP folder operators.

The Forbes 30 Under 30 and What It Meant

Zhang's appearance on Forbes' 30 Under 30 list in the Enterprise Technology category was not a vanity milestone. It was a signal about how seriously the startup ecosystem was taking the developer-tools-for-physical-infrastructure space. By that point, Lob had demonstrated that the market was not theoretical. Enterprises were paying real money to automate their print workflows. Zhang had built a company from a ski trip conversation, through a YC batch, through a home printer phase, into something that was rewriting how the Fortune 500 thought about direct mail.

His dual degree in Informatics and Business Administration at Michigan's Ross School - class of 2011 - gave him the vocabulary for both sides of the Lob equation. He could talk to developers about API design and to CMOs about campaign ROI. That bilingualism is rarer than it sounds in enterprise software, and it shows in how Lob was built: technical enough to win developer champions, polished enough to close enterprise deals.

A Career Built on the Bridge Between Tech and Operations

Before founding Lob, Zhang spent time at Ford Motor Company in early career roles, then moved to Roland Berger Strategy Consultants, and then to Microsoft - where the FTP folder problem crystallized. His path was not the typical "dropped out of Stanford to build a startup" story. He earned his degrees, worked in operations and strategy, and arrived at entrepreneurship through frustration with the gap between how software companies talked about automation and how they actually operated.

The Microsoft chapter is the one that mattered most. Managing field marketing for Project and Visio meant living inside the exact problem Lob would solve. The irony was structural: at a company whose product was workplace productivity software, the process for sending direct mail was still painfully manual. If Microsoft could not automate its own FTP-folder-and-print-vendor workflow, no one else could either - not without a proper API layer. Zhang decided to build it.