AI21 Labs

AI21 Labs was founded in 2017 in Tel Aviv by Yoav Shoham (Stanford AI professor emeritus, ACM-AAAI Allen Newell Award), Amnon Shashua (Mobileye CEO, Hebrew University professor), and Ori Goshen. Raised ~$283M at a $1.4B valuation. NVIDIA was in advanced acquisition talks ($2–3B) as of late 2025; those talks fell through, and a Nebius acquisition discussed in April 2026 ended as a commercial partnership to integrate AI21's Maestro agent platform into Nebius's cloud. In May 2026 AI21 laid off 110 of its 180 employees and halted development of the Jamba model family, leaving Maestro as its main active product line.

AI21 trained the Jurassic series (2021, 178B dense) and then introduced the Jamba architecture (2024) — the first production-grade SSM-Transformer-MoE hybrid combining Mamba state-space layers with Transformer attention and mixture-of-experts routing. Jamba 1.7 Large (398B total / 94B active, 256K context) was its last flagship before Jamba development stopped. The hybrid architecture achieves 2.5x faster inference than equivalent dense Transformers while fitting on a single 80GB GPU.