Jonathan Avni

Product Leader. AI Builder.

13+ years shipping developer APIs and payments infrastructure at Coinbase, Paxos, Pinterest, and Yahoo. Now building at the intersection of payments and AI agents: training models, shipping products, and writing about what I learn.

Jonathan Avni

Where I've Been

2012–2015

Yahoo

Product Manager

Founding team member of Yahoo Gemini, powering monetization across Yahoo properties (over 1B MAUs at the time). Grew revenue from launch to $1B+ run-rate.

2015–2018

Pinterest

Product Manager, Monetization

Launched Marketing APIs used by 100+ partners, accounted for 50%+ of 2018 revenue.

2019–2021

Coinbase

Senior Product Manager, Payments Platforms

Built payments and trading infrastructure for Coinbase Retail and Enterprise customer-facing products, moving hundreds of billions of dollars in annual transaction volume.

2022–2024

Paxos

Product Lead, Stablecoins and Banking

Built and launched PayPal USD, a leading fully regulated USD stablecoin, and scaled it to a market cap of over $3B through dozens of distribution partner integrations.

2024–Now

Independent

AI Builder

Trained an LLM from scratch, published fine-tuned adapters on Hugging Face, built a RAG platform with paying users, and open-sourced two agent frameworks.

A common thread: I've always chased the most interesting technology of the moment - ads marketplaces, social APIs, crypto protocols, stablecoins - and now AI.

Selected Projects

LLM Fine-tuning Course screenshot

LLM Fine-tuning Course

Live

Fine-tuning a 3B language model end-to-end on the HF Hub: SFT, DPO, and a vision-language sidetrack

I worked through Hugging Face's Smol Fine-Tuning Language Models course and shipped a preference-aligned small model to the Hub. SmolLM3-3B-Base taken through SFT on 12k summarization examples, then DPO on 12k preference pairs, with DPO continuing to train the same LoRA rather than starting fresh (and the pre-DPO state frozen as the reference policy). A SmolVLM2-2.2B ChartQA adapter sits alongside as a vision-language sidetrack, where LoRA adapts the LLM while the SigLIP vision encoder stays frozen. Four LoRA adapters published, all reproducible from the public code.

PyTorchHugging Face TRLPEFT (LoRA)HF Jobs (A100/A10G)Python 3.12
Deep Research Agent screenshot

Deep Research Agent

Live

An agentic research system with planning, sub-agent delegation, and human-in-the-loop approval

A deep research agent that takes a question, breaks it into a research plan, waits for human approval, then hands research tasks to isolated sub-agents that search the web and synthesize findings. Uses file-based context offloading instead of context stuffing, and runs Gemma 4 locally via Ollama or any cloud LLM.

LangGraphLangChainGemma 4OllamaTavily API
KuchiClaw screenshot

KuchiClaw

Live

A minimal AI agent framework: ephemeral containers, living file memory, filesystem IPC

A personal AI agent that runs 24/7 on a VPS, talks through Telegram, manages its own memory, sends emails, and runs scheduled tasks autonomously. Built on the Claude Agent SDK with ephemeral Docker containers, living markdown files for memory, filesystem IPC, and a two-tier skills system (shell scripts + MCP).

Claude Agent SDKTypeScriptDockerTelegram Bot APISQLite
TinyBrain screenshot

TinyBrain

Live

An AI that earns and spends money autonomously via x402

An inference service built on top of TinyChat that charges $0.01/query via the x402 payment protocol. Routes complex queries to DeepSeek R1 for ~$0.001, pocketing the difference. Includes complexity classification, a "bar tab" payment mode with stateless HMAC-signed sessions, and wallet integration on Base mainnet.

Next.js 15React 19x402 Protocolwagmi/viemUSDC on Base
TinyChat screenshot

TinyChat

Live

A 561M-parameter LLM trained from scratch for ~$95

A language model built from scratch: custom BPE tokenizer, GPT architecture with RoPE and Multi-Query Attention, trained on ~38B tokens from FineWeb-EDU, then fine-tuned for conversation. Deployed on Modal serverless GPU with a Next.js frontend.

PyTorchModal (T4 GPU)Next.jsTailwind CSSSSE Streaming
Talk2Docs screenshot

Talk2Docs

Sunset

A full-stack RAG platform for chatting with PDFs, URLs, and podcasts

A RAG platform for chatting with your documents: custom chunking, hybrid retrieval, query classification, multi-document synthesis, and citation validation. Built with Next.js, Supabase, Stripe, and Clerk, deployed on Vercel and Railway.

Next.js 15React 19TypeScriptSupabase + pgvectorOpenAI GPT-4.1