telli

About Us

About UsAt telli, we're building the first AI-native phone system. Since launching last year at Y Combinator (the same investors behind Airbnb, Stripe, Twitch, Coinbase, and others), we've grown >$2M in annualized revenue with a team of only 12 people. Today, many companies fail in their customer communication not because they don't care, but because they can't keep up. The sheer volume of calls forces to rely on low-quality outsourced call centers or have their internal teams waste hours on repetitive calls. With telli, our customers now rely on AI voice agents that handle their repetitive calls, freeing human to focus on what matters - talking to customers when it counts. The result: higher efficiency, happier teams, and better customer experiences. Legacy phone systems weren’t designed for an AI-first world.

That is why we are building the first AI-native phone system that lets companies manage both their human and AI teams on one platform. Our founding team knows this problem inside-out. We ran a 150-person internal call center at Enpal. We know how difficult and expensive it is to scale high-quality customer experience with phone calls. The opportunity is massive!!! and we're just getting started. We're on a mission to let every company provide a world-class customer experience by ending the era of low-quality call centers.

About The Role

About The RoleThis is a high-ownership, high-impact role for engineers who care about velocity and solving real customer problems. You won't just ship code; you will own projects end-to-end, make core product and architectural decisions, and shape the future of this company.We believe in building a small A* engineering team. We plan to keep the core engineering team small, even while we scale and rely on engineers who have super high impact on the growth of the company. That is why to succeed, you need to be comfortable with working on any part of our stack. One week you might be polishing the UX of our frontend, the next week dive deep into async processing challenges of our voice AI infrastructure. If you only want to work on a specific technology/part of the product, this might not be the right role for you.

What You Will Dowork

What You Will Dowork closely with our customers, understand their problems, and come up with product experiences that solve their challengesbuild scalable backend infrastructure to handle thousands of AI phone calls a daybuild intuitive user experiences that make sense in an AI-first worldown high stakes projects end-to-endtech stack

tech stack

Our tech stack includes TypeScript, React, TanStack, Node, Python, Postgres as well as Temporal.io, Twilio, and Modal. But more than familiarity with any specific technology, we value a how fast you can learn and the ability to ship end-to-end features.

What Makes You a Great Fit

What Makes You a Great Fityou align with our principlesyou love challenging work and consistently go above and beyondyou take full ownership of projectsyou want to work in-person in Berlinyou know how to prioritize high-leverage workyou want to work with a smart and driven team with (self-reported) low egoyou want to help build a multi-billion dollar company from the ground upyou may _ not _ make a good fit if…you prefer a remote-first environmentyou like to work on your own with minimum collaborationyou have no prior experience in software engineering teamsyou only want to work with specific technologies instead of the entire development stackyou think AI is just "hype" and doesn’t provide real valueyou want to work 9-5 perksabove-market pay & equityaccess to any (AI) tool that makes you more productiveurban sports subscriptionrelocation support if you don't live in Berlin