Blockit - Betting on a Network for Time

An Idea That's Been Cooking for 10 Years

I rarely take inbound recruiter outreaches seriously, oftentimes because I know these recruiters are likely shipping out hundreds of emails each day to get a response from people and because none of these outreaches are personalized to me. I also don’t have the time to go research the companies or startups they represent. In fact, earlier this year, I got an email from a recruiter about a potential founding engineer role at Blockit. I replied out of curiosity, but didn’t follow up again: I didn’t have time to validate the opportunity.

That changed when Karen, a Harvard alum I’d heard about back in school, reached out a few days later. I decided to hop on a call with her, and soon after, with Kais and John, Blockit’s co-founders. Those conversations completely shifted my perspective on the company, and I’m super, super excited to be doing this company profile on them to share their vision, a vision that I strongly resonate with! In fact, after my call with Kais, I was on the verge of asking to join their team.

Blockit’s founder, Kais Khimji, first conceived the idea for Blockit during his sophomore year at Harvard. Over the years, he made several attempts to bring it to life but, as a Canadian founder, often ran into visa and immigration hurdles that made building in the U.S. difficult. After graduating, Kais joined Sequoia Capital as an investor. Yet his conviction in Blockit’s problem space never wavered, and ten years later, he has assembled a team of ten to bring this vision to life. What especially drew me in to Blockit’s vision wasn’t necessarily the idea itself but rather Kais as a founder. When asked about the team, Kais named every single member, highlighting their background and the intentionality behind each hire: Chung came from Waymo, one of the only AI applications that is currently stateful and can handle multi-player AI interactions which Blockit has been expanding into; Pruthvi was a new grad having interned at Notion and Asana and a desire to operate early-stage on cutting-edge technology; and Karen, with offers from Cursor and Mercor after graduating from Goldman’s TMT program, was chosen to lead and scale the company’s business operations.

Blockit’s Virality and The Network Effects

When Kais left his role at Sequoia Capital to build Blockit, he did so very quietly. In fact, his LinkedIn hasn’t updated yet, Karen’s LinkedIn is now completely gone, and John’s LinkedIn has an obscure “Member of Scheduling Staff” title. The reason for this stealth is because Sequoia’s name carries a heavy spotlight, and Kais didn’t want his departure to spark headlines or speculation before the product was ready. Ironically, while he was avoiding attention, Blockit began spreading entirely on its own.

What makes Blockit’s early traction remarkable is that its growth wasn’t driven by marketing or press, but rather pure virality. At its core, Blockit is an AI-powered scheduling assistant that takes the pain out of coordinating meetings. Think of it as your personal executive assistant that not only schedules your meetings based on your calendar availability and preferences, but in the future, will hopefully be able to optimize your schedule for you, blocking out necessary times to focus and meet with certain individuals.

Kais had studied products like Calendly, understanding how strong network effects emerge when a tool naturally embeds itself in people’s workflows. With Blockit, every email thread or calendar interaction carries the potential to introduce new users because the application is cc’d onto the email exchange to help you schedule times to meet. Similar to how you can automatically track your applications by cc’ing your Niche-specific email, with Blockit, you can cc your Blockit agent email to surface and schedule times to meet with the email recipient. This simple, frictionless workflow not only makes scheduling easy but creates a network for Blockit users. Whenever someone you email also cc’s their Blockit agent, both sides instantly connect through the system, creating an “autoblocking” effect where every interaction introduces new users and strengthens the network. The introduction feels organic, which is precisely why Blockit has grown without relying on ads, hype, or forced growth tactics. Indeed, recipients (people copied onto Blockit-powered emails) have already begun to perceive themselves as users of the application, reinforcing the brand’s utility and presence.

Despite its growing footprint, Blockit still has no real competitors in its space. Kais notes that even announcing the company publicly would likely attract immediate media attention, but for now, they’re content to grow under the radar.

Interestingly, the team made a few intentional design choices that shaped the product’s virality. One key insight was avoiding the pitfalls of over-humanizing AI. Products like Clara AI or xAI had seen negative virality where users became uncomfortable when they realized a “person” they were emailing wasn’t. The team believes that the future will be people knowingly interacting with AI and has taken steps to not anthropomorphize the product accordingly.

Betting on a Network for Time

Kais’s bet is a question about time and why, for this very digitalized and structured form of data, is it still trapped inside siloed calendars? Companies and individuals already maintain “time databases” in the form of a calendar. Yet unlike email, which became interoperable across organizations in the 1990s, time is still fragmented. You can only really schedule calendars within your own company’s or school’s ecosystem, and there has yet to be a network of time, a shared protocol that connects how we book, meet, or collaborate.

Kais compares today’s calendar tools to a SQL database hidden behind a clunky interface. Each “block” of time is static, hard to connect, and dependent on manual coordination. There is no “typescript for calendars” or a structured way to reason about logic of time and automate its flow, and for now, we have only relied on executive assistants or manual tools like Calendly/When2Meet to manipulate this logic.

Blockit’s core insight is to move the interface of time from conversation into a connected database layer, the same way Uber transformed phone calls into ride requests and DoorDash turned restaurant bookings into delivery APIs. Whoever succeeds in making the world’s time interoperable, Kais argues, will unlock immense productivity and coordination gains.

And at the foundation of that interoperability lies the calendar graph. While LinkedIn captures binary relationships (“connected” or “not connected”), the calendar graph is weighted because it knows not just who you know, but how well you know them via how often you meet, for how long, and in what context (Zoom, in-person, urgent, recurring). This creates a more authentic and dynamic representation of professional networks. The one drawback though, is that this model only really works when your network lives on your calendar. This is the case for much of the professional world in VC, IB, Consulting, or Tech, but not so much the case for students or people earlier-on in their career.

The Team at Blockit

When I asked Kais who they were looking for at Blockit, he emphasized the importance of a team that deeply cares. Blockit wants engineers that thrive when working with others to collaborate on ideas. There’s a common myth in tech about what great engineers look like (24-year-olds, fueled by Red Bull, pulling all-nighters and churning out thousands of lines of code), but Kais has found that great engineers treat coding as a deeply social act, not a solitary grind. IQ is a threshold but EQ is a max function such that intelligence can get you through the door, but emotional intelligence determines how far you go.