Hacker: AI coding tools perform poorly on large codebases and create unfixable tech debt
Severin Hacker · Duolingo Co-Founder, Severin Hacker: How AI Impacts the Future of Work and Education · 20VC with Harry Stebbings · May 19, 2025 · at 12:55
Severin Hacker is the Co-Founder and CTO of Duolingo. He shares his technical observation after testing AI software engineering tools such as Replit and Lovable.
0:00 / 0:30exact quote · 31.0s
▶ Watch the full episode on YouTube → 720p mp4 · rendered on demand · StarZero watermark
“On the software engineering side, I think what they're really good at is going from zero to 80% for a simple app. You know, it's like, it's the replet, the lovable, and then the larger the code base, even the one that generates itself, the larger the code base gets, the worse they get. So then, you know, it's just kind of like adding the next 10% Takes as long as the first 80%, and they kind of create their own tech debt which they also cannot really solve.”
quote is from the automated transcript, cleaned for reading: filler sounds and stutters are removed, nothing is rephrased. names can be misheard (the analysis reads context, assessments check outside sources). how →
More from Severin Hacker
Hacker: Duolingo could not have raised any funding in Europe
“But I can guarantee you Duolingo would not have been able to raise any money in Europe.”
Severin Hacker: AGI and UBI will replace human jobs in 20 years
“I believe that's gonna happen. Again, the big question is, is when is it gonna be? I don't think it's gonna be next five years. It's not going to be, maybe it's going to be next 10 years if you really see a broad adoption of these technologies, more likely may…”
Hacker: Many edtech companies are 'homework cheating' businesses hit by ChatGPT
“When ChatGPT came out, one of the first killer use cases for it was homework cheating, for the lack of a better term, okay? So if you were in the homework cheating business, That was devastating. That was really bad. So, so some of our, I'm not going to name t…”
Hacker: European AI founders should 100% move to Silicon Valley
“If a young founder, European founder came to me, it's like, Hey, I have this brilliant idea of how to use AI or like a new model or something like that. What should I do? It's like a hundred percent. Go to Silicon Valley. A hundred percent. You absolutely maxi…”
Hacker: European skepticism toward founder ambition harms its tech ecosystem
“I think a lot in, a lot of people in, in Europe, you just like, you're kind of like, why are you doing this? Like, why, why, you know, like, or they look at it as like, oh yeah, you know, they're just doing it for the money or there's this suspicion. Almost of…”
Hacker: Strict US immigration rules would benefit European tech
“In a way, the best thing that could happen to Europe is if the U.S. Made it really hard to immigrate for founders. You know, if they made it really hard, if they restricted immigration such that you know, people like me couldn't, couldn't move there anymore, t…”