Podcast Summary: The Pragmatic Engineer

Episode: Being a Founding Engineer at an AI Startup
Host: Gergely Orosz
Guest: Michelle Lim
Date: December 3, 2025

Overview

This episode dives deep into the journey and mindset of being a founding engineer at an AI startup, through the experiences of Michelle Lim. Michelle, previously the founding engineer at Warp and now founder of Flint, shares how she navigated her career from internships at Big Tech, took the leap to early-stage startups, and what it takes to excel as a founding engineer—especially in high-growth, AI-driven environments. The discussion touches on the differences between product and infrastructure engineering, candid advice on equity negotiations, reference checks for founders, and how today's engineers can prepare for pivotal roles in startups and AI.

Key Discussion Points & Insights

1. Michelle’s Early Career and Attraction to Startups

• Progression Through Internships:
  Michelle’s internships ranged in company size from Meta (12,000), Slack (1,200), to Robinhood (300), each move giving her more responsibility and product ownership.
  “Every time I went down roughly an order of magnitude, I felt way more ownership… obviously the next step is joining a two-person company and then starting my own.” (00:00 – 00:21)

• Discovery of Passion for Debugging:
  Started out in computer science late (spring freshman year) yet quickly fell in love with debugging, likening it to medical diagnosis.
  “I started seeing that there was always a pattern in which debugs occurred and I could trace it back to specific lines of code or systems… almost like I was a doctor for the computer.” (02:25 – 03:43)

• Learning Across Different Environments:
  Her internships at Meta, Slack, and Robinhood helped develop both technical and product skills. Notably at Robinhood, she was responsible for the News tab feed logic, handling both backend pipelines and product design choices for millions of users.
  “At Robinhood, I really found my sweet spot…activating all parts of my brain, technical and product side.” (09:51 – 11:34)

2. Choosing to Join a Little-Known Startup (Warp)

• Evaluating Startup Risk:
  Michelle had offers from “rocket ship” Series A startups with millions in ARR but chose Warp, which had no codebase yet—just product mocks and a passionate founder, Zach.
  “There wasn’t any code written yet at the time… I could always look for a job in any of these $10 million ARR companies, but it’s so rare to coincide with the window… and get the chance to be the first engineer.” (13:07 – 21:15)

• Reference Checks—in Both Directions:
  Michelle uniquely requested references from the founder, believing it’s as important to assess your manager as it is for them to assess you.
  “You don’t leave companies, you leave managers… at a startup, you are married to that manager. So you need to learn as much as possible about what it would be like working with them.” (26:20 – 27:44)

Notable Quote:

“If I as a founder am evaluating a candidate, the most important question I ask is, would you want to work with this person again? And the answer I’m looking for is not yes. The answer I’m looking for is hell yes.”
—Michelle Lim (27:44)

3. Equity, Negotiation, and Career Decisions

• Equity Negotiations:
  Michelle negotiated aggressively for equity over cash (“I was willing to go extremely low on cash.”), and credits her spreadsheet and negotiation strategy to her founder at Warp. She now provides similar resources to candidates at her own startup. (22:30 – 24:38)

• Advice on Negotiating with Startups:
  Michelle advocates for openness and authenticity with founders, differing from strategies typically advised for large corporations.
  “It really means a lot to the founder that you are bought in, ready to go, excited to help them, and they want you to be happy and have a good deal.” (24:38 – 25:39)

4. Technical Choices and Stack Evolution

• Technology Shift from TypeScript to Rust at Warp:
  The early team rebuilt the terminal from TypeScript to Rust for performance and developer sentiment.
  “There was a very strong sentiment among developers that they would only use high-performance terminals built at low levels… It was also important for marketing that we built in Rust.” (33:10 – 35:20)

Notable Moment:

“It was really funny when we decided to build in Rust… Zach sent the O’Reilly Rust Book to everybody…and every day we learned something new, we’d rewrite what we had done previously.”
—Michelle Lim (33:10 – 35:20)

• Pair Programming for Learning:
  Michelle paired with Nathan Sobo (Atom editor creator) to ramp up in Rust, emphasizing the value of learning directly from experts.
  (35:20 – 35:22)

5. Product Engineer vs. Infrastructure Engineer

• Product First vs. Code First:
  Michelle distinguishes between engineers motivated by user impact (product) and those excited by technical elegance (infrastructure/code).
  “I found that this division is a way better split to think about engineering than front end and back end.” (37:22 – 38:08)

• Signals for Hiring Product Engineers:
  Product engineers think in terms of users and business impact. In interviews, Michelle looks for real product insights, milestone thinking, and the ability to propose features from a user-centric perspective.
  “The best candidates know how to talk about features from a user’s perspective and group work into user-visible milestones.” (38:40 – 40:42)

6. Cautionary Tales and Red Flags

• Risks at Early Stage Startups:
  Michelle warns about founders selling (“equi-hires”) and leaving their teams behind, and stresses checking founder character via reference checks and interview questions.
  “It’s all about really understanding the character of the founder… Ask them directly if they’ve thought about secondary offers, team retention, and similar scenarios.” (46:14 – 48:48)

Notable Advice:

“Don’t listen too hard on what their answer is, but listen for whether they have thought about it before.”
—Michelle Lim (48:48)

7. Excelling as a Founding Engineer

• Volunteer for Unsexy Jobs:
  Michelle’s rise involved taking on unattractive but essential work—becoming the face of Warp on Hacker News, running social media, onboarding, even leading enterprise sales.
  “It’s about volunteering to do the things that no one wants to do, but it’s the most important thing for the business.” (57:01 – 60:23)

• Gaining Broad Experience:
  Tackling a mix of technical and business responsibilities positioned her for eventual roles in management and ultimately founding her own startup.

Notable Moment:

“Because I was doing all these things and hiring all the people, after a board meeting my founder told me, ‘I want you to be head of Growth.’ Suddenly, I was reporting to the board, at 22.”
—Michelle Lim (58:07 – 59:35)

8. Building and Hiring for a Modern AI Startup

• Flint’s Vision—Autonomous, Agentic Websites:
  Flint’s product is an AI platform that builds, optimizes, and evolves websites automatically, integrating with sales calls and market signals.
  “The website itself becomes agentic—they build themselves… waking up to a competitor, your site responds with new comparison pages, optimized copy, etc.” (50:20 – 53:10)

• AI Coding as Baseline:
  At Flint, coding with AI tools (Cloud Code, Cursor, etc.) is now standard in the development workflow.
  “It’s almost a requirement at this point to use AI to code because then you can be more productive.” (44:47 – 45:19)

Timestamps for Important Segments

• 00:00 – 02:25: Michelle’s path into software engineering
• 03:57 – 11:34: Early learning from internships at Meta, Slack, Robinhood
• 13:07 – 21:15: Choosing the risk of joining Warp as first engineer
• 22:30 – 25:39: Equity negotiation and founder-candidate dynamic at early-stage startups
• 26:20 – 27:44: Reference checks for founders
• 33:10 – 35:20: Technology stack change – TypeScript to Rust at Warp
• 37:22 – 40:42: Product engineer vs. infrastructure engineer mindsets
• 46:14 – 48:48: Warning signs and important founder questions for early-stage hiring
• 57:01 – 60:23: Going above and beyond as a founding engineer
• 50:20 – 54:28: Flint’s approach to autonomous, agentic websites

Memorable Quotes

• “It is so important to negotiate for equity… I argued very hard for the one with the most equity, and I was willing to go extremely low on cash.”
  —Michelle Lim (22:30)

• “At a startup, you are married to that manager. So you need to learn as much as possible about what it would be like working with them.”
  —Michelle Lim (26:44)

• “Whenever they pass you a job to be done, it would be done excellently. And then this way you get more and more responsibilities… before you know it, you might be running enterprise sales because no one wanted to work on security questionnaires.”
  —Michelle Lim (59:35)

• “Everything we know about the Internet is about to change and Flint is building that, even today.”
  —Michelle Lim (54:52)

Takeaways & Advice

• For Aspiring Founding Engineers in AI:
  Build something with AI (even if small), show experience with new tools, and look for opportunities at the intersection of high-growth, deep tech, and product ownership.
• When Considering Startups:
  Reference check your manager/founder, understand the nuances of equity, and ensure your values align—especially around support, growth, and commitment to early employees.
• To Succeed as a Founding Engineer:
  Excel technically, volunteer for business-impactful work outside your job description, and develop a broad-based understanding of both products and people.
• For Founders Hiring Today:
  Value cross-functional skills and high-trust culture, and look for engineers who can rapidly evolve with business needs.

Rapid Fire: Michelle’s Favorites

• Programming Language: Rust (“Satisfaction from passing the borrow checker”; 61:10)
• Stack at Flint: TypeScript; but open to other languages for the right fit (61:23)
• Movie Recommendation: Weapons—nonlinear narrative, mixes genres, smart horror (61:43 – 62:53)

Closing

Michelle’s journey offers a real-world roadmap for anyone considering a leap into founding engineering roles, especially in the new wave of AI startups. Her story underscores the value of risk-taking, authentic connection with founders, the power of learning through “unsexy” but critical work, and the need for broad, business-oriented technical skills in today’s tech ecosystem.

For complete resources and articles discussed, see the Pragmatic Engineer Deep Dives linked in the episode show notes.