§ Tianchi

Resume

Tianchi Cai.

Founder & CEO at Saddlepoint AI. Previously led RL & RAG at Ant Group and chat-model alignment at MiniMax. 10+ peer-reviewed papers; WSDM 2023 Best Paper Runner-up.

Role: Founder & CEO Focus: LLMs · Reinforcement Learning · RAG · Agent Harnesses Based: Beijing / Hangzhou

§Now

2025 — Present active

Founder & CEO

Saddlepoint AI
  • Saddlepoint: when a direction hits a local max, find a new dimension to optimize. Orthogonal dimension-shifting as our core way to innovate.
  • Building nodie.ai — a local-first agent workstation for AI-built software, and nodie claw — a desktop multi-agent harness.

§Experience

2024 – 2025

Chat model alignment — Xingye & Talkie

MiniMax
  • Led alignment of Xingye and Talkie chat models to human preference and product requirements.
2018 – 2024

Lead, RL & RAG team

Ant Group
  • Led RL, RLHF, RAG, and large-scale ranking / decision systems.
  • First production-scale RL system for marketing budget allocation. Saved billions of RMB annually.
  • 10+ papers, WSDM 2023 Best Paper Runner-up.
2017

SWE Intern, Ads

Google
  • Full-stack intern on the Ads team.

§Education

2013 – 2018

The University of Hong Kong

B.A. Philosophy → Math & CS track
  • ACM-ICPC Asia Regional Gold medalist.
  • Four-year scholarship; LSE summer school in microeconomics.