A Poolesville High School junior is building a fast-growing internship platform that has already attracted more than 22,000 users worldwide and landed him in Silicon Valley founder circles.
Sarthak Pal Mahajan, a Montgomery County native and student at Poolesville High School, is the cofounder of Klinn, an internship-hunting platform designed for high school and college students. Mahajan began working on the idea in the summer of 2024 and later teamed up with his cousin and cofounder Andrew Wang, a 17-year-old from Texas, after meeting through a high school research Discord server.
What started as a side project quickly evolved into a full platform offering a mix of free and paid tools, including an extracurricular and internship database, a cold-emailing tool to help students reach potential employers, and partnerships with startups offering perks and internship opportunities. Klinn officially launched its first product in October 2024 and has since gone through multiple iterations as the team tested ideas, gathered feedback, and refined their offerings.
Growth accelerated earlier this year when Mahajan began posting about Klinn on LinkedIn. Several of his posts went viral, drawing thousands of comments from users sharing their email addresses. Those connections helped push Klinn’s user base well beyond its original Maryland roots, expanding to users across the United States and more than 120 countries.
Unlike many internship platforms that charge students or schools, Klinn focuses on serving startups. The platform helps companies hire interns by pre-vetting candidates through hiring assessments, narrowing large applicant pools down to a small group of top candidates. Mahajan said the goal is to save startups time while giving students more meaningful opportunities, rather than forcing them to compete with hundreds of unqualified applicants.
Balancing school and startup life has been demanding. Mahajan said most of his afternoons and late nights are spent working on Klinn or completing schoolwork, often using long bus rides to catch up on rest. Having a cofounder, he said, has made the workload more manageable, even while collaborating remotely across state lines through calls, messages, and online tools.
Klinn’s growth has also opened doors beyond Montgomery County. Mahajan has been flown to San Francisco twice, once for a16z Tech Week and once for a founder-in-residence program, experiences he described as transformative. During those trips, he met founders, investors, and entrepreneurs and spent time inside startup offices, gaining exposure to the fast-moving startup ecosystem.
So far, Klinn has helped match students with startups including YC-backed companies, assisted students with internship applications, and supported international students pursuing educational opportunities. The team is currently refining its hiring assessment and running pilot programs with companies, with plans to scale the platform further. While they are not actively seeking funding, Mahajan said they are open to joining an accelerator program this summer.
Mahajan credits Montgomery County and Poolesville High School for shaping his entrepreneurial mindset. He described Poolesville as an environment filled with motivated and talented students across academics, research, robotics, debate, and increasingly, entrepreneurship.
As he looks ahead, Mahajan said he plans to continue building Klinn through college, with the long-term goal of scaling the platform as much as possible.
