Jack Collins
81 posts

Jack Collins
@jackmpcollins
Building with LLMs. Prev. Founding Engineer at Develop Health ($7M ARR w/ 5 employees). Creator of magentic




Create internal communications content that people actually want to pay attention to.


$1M ARR per employee. $400M+ ARR combined. Almost all <5 years old, <50 employees and Profitable. This wasn’t a YC dinner. This was the first Lean AI Leaderboard dinner 🔥 Massive thanks to @FAL ($50M+ ARR with just 22 people!) for hosting a 7-course sushi + wagyu feast at Ozumu SF — bringing together the founders behind the most efficient and fastest-growing AI startups today. Almost everyone in this room is doing >$1M revenue per employee. Most are profitable. All were founded in the last 5 years. And they’re just getting started. @FAL @aragon_ai @higgsfield_ai @pika_labs @openart_ai @tavus @AkoolInc @hedra_labs @conversionai DevelopHealth This is what the future of company building looks like: AI-Native, Lean, Fast Growing and Profitable. Next up: I’m co-hosting a Lean AI Happy Hour in SF at the end of the month with @hanstung @chelcietay Camila Katz from @notablecap If you’re building a Lean AI Native company, drop a comment and I’ll get you an invite 👇

magentic v0.36.0 is released and (finally) makes the `Chat` class public and documented


🔬 Spent an hour diving deep into magentic.dev , an LLM framework from @jackmpcollins. And I found a similar challenge as I get with a lot of these frameworks... debugging <> abstracted control flow. 📝 Core lesson for frameworks: Take extreme care when your 'abstraction' abstracts _control flow_. When debugging AI, you need to trace everything - from prompt construction to response parsing; and many LLM frameworks don't consider this deeply enough. 🛠️ I built a calculator to test some function calling workflows. I played a lot with the various decorators and finding where and how to break the framework. Missing a return type? opaque Pydantic error. Unused prompt template parameter? No worries, it'll run. Any function can be a tool. 💭 Overall: Framework shows promise but I think there are some changes I would want to see before recommending use. ✅ What worked well: - Clean function calling implementation - No specialized tool decorators (just Python functions!) - Solid type system with Pydantic - Built-in image support that's actually usable ❌ Pain points: - Too many overlapping concepts (prompt/chatprompt/prompt_chain) - No validation between templates and parameters - Observability locked to logfire; no clear way to "bring my own logging" - Missing escape hatches for new features 💡 Recommendations: - Simplify API - merge overlapping concepts; the conceptual weight is high given the functionality - Add prompt template <> parameter validation to prevent incongruence - Make observability pluggable (repeat after me: LLM observability is just observability) - Focus on composable primitives over abstractions After over a decade of building ML systems: frameworks should give developers control flow visibility. You'll need it at 3am debugging hallucinations in prod.


magentic v0.36.0 is released and (finally) makes the `Chat` class public and documented










