Jason Jia retweeted
Try Underdog: free, capable, private AI running locally on your device
New build and Saluki 27B are out. Under 8GB, beats Qwen 3.8 27B at tool calling
Like, repost, and comment one task you wouldn’t give a cloud agent to get an invite🦴
Today we're releasing Underdog Saluki 27B
Based on Qwen 3.8 27B, Saluki is almost 7x smaller than its full-precision counterpart while it keeps 96% of its benchmark performance and beats Qwen at tool calling
It's the best model <8GB that runs in Underdog
Saluki is available today under Apache 2.0. Try today in Underdog underdog.ai/saluki
Jason Jia retweeted
- you:
- want to actually learn how LLMs work
- sick of “just start with linear algebra and come back in 5 years”
- decide to build my own roadmap
- no fluff. no detours. no 200-hour generic ML playlists
- just the stuff that actually gets you from “what’s a token?” to “I trained a mini-GPT with LoRA adapters and FlashAttention”
- goal: build, fine-tune, and ship LLMs
- not vibe with them. not "learn the theory" forever
- build them
- you will:
- build an autograd engine from scratch
- write a mini-GPT from scratch
- implement LoRA and fine-tune a model on real data
- hate CUDA at least once
- cry
- keep going
- 5 phases
- if you already know something? skip
- if you're lost? rewatch
- if you’re stuck? use DeepResearch
- this is a roadmap, not a leash
- by the end: you either built the thing or you didn’t
- phase 0: foundations
- if matrix multiplication is scary, you’re not ready yet
- watch 3Blue1Brown’s linear algebra series
- MIT 18.06 with Strang, yes, he’s still the GOAT
- code Micrograd from scratch (Karpathy)
- train a mini-MLP on MNIST
- no frameworks, no shortcuts, no mercy
- phase 1: transformers
- the name is scary
- it’s just stacked matrix multiplies and attention blocks
- Jay Alammar + 3Blue1Brown for the “aha”
- Stanford CS224N for the theory
- read "Attention Is All You Need" only AFTER building mental models
- Karpathy's "Let's Build GPT" will break your brain in a good way
- project: build a decoder-only GPT from scratch
- bonus: swap tokenizers, try BPE/SentencePiece
- phase 2: scaling
- LLMs got good by scaling, not magic
- Kaplan paper -- Chinchilla paper
- learn Data, Tensor, Pipeline parallelism
- spin up multi-GPU jobs using HuggingFace Accelerate
- run into VRAM issues
- fix them
- welcome to real training hell
- phase 3: alignment & fine-tuning
- RLHF: OpenAI blog -- Ouyang paper
- SFT -- reward model -- PPO (don’t get lost here)
- Anthropic's Constitutional AI = smart constraints
- LoRA/QLoRA: read, implement, inject into HuggingFace models
- fine-tune on real data
- project: fine-tune gpt2 or distilbert with your own adapters
- not toy examples. real use cases or bust
- phase 4: production
- this is the part people skip to, but you earned it
- inference optimization: FlashAttention, quantization, sub-second latency
- read the paper, test with quantized models
- resources:
- math/coding:
- 3Blue1Brown, MIT 18.06, Goodfellow’s book
- PyTorch:
- Karpathy, Zero to Mastery
- transformers:
- Alammar, Karpathy, CS224N, Vaswani et al
- scaling:
- Kaplan, Chinchilla, HuggingFace Accelerate
- alignment:
- OpenAI, Anthropic, LoRA, QLoRA
- inference:
- FlashAttention
- the endgame:
- understand how these models actually work
- see through hype
- ignore LinkedIn noise
- build tooling
- train real stuff
- ship your own stack
- look at a paper and think “yeah I get it”
- build your own AI assistant, infra, whatever
- make it all the way through?
- ship something real?
- DM me.
- I wanna see what you built.
- happy hacking.




