From Monolithic Blending to Agentic Orchestration: Dynamic Response for Conversational Assistants at Scale

Cen Zhao, Peng Wang, Chuan Shi, Yufeng Zhang, Ying Lyu, Wanmeng Ren, Robert Xue, Claire Cheng, Yashar Mehdad


Abstract
Conversational assistants can blend retrieval, action selection, escalation, and wording in one model path, or separate those roles. We report a production migration of a conversational assistant for customer support at a large accommodation marketplace (millions of conversations per month, 11 languages, 10-second P90). Dynamic Response (DR) replaces a single Qwen3-235B-A22B blended responder with a bounded ReAct orchestrator over typed tools plus a smaller generator that writes from a backend-validated context contract. Because the migration also changed prompts, alignment, and serving, we attribute each effect to its cause and claim as architecture effects only those measured on identical replayed turns: typed entity selection moves the reservation selector to a precision-first operating point (precision 8.3% to 89.1% at recall 75.2% to 67.3%), and typed action IDs with a membership check remove observed structured-action hallucination (2.14% to 0.0%). A low-ramp A/B test reproduces the replay escalation reductions: hard-escalation responses fall 5.60% to 3.08% and soft-escalation responses 9.56% to 2.49% while production handoff volume holds roughly steady, and self-solve is directional (+5.1 points, 95% CI [-2, +12]). Serving optimizations cut orchestrator P90 from 3.87s to 2.24s on a GPU footprint reduced by roughly one-third, and self-hosting reduces estimated annual model-serving cost by more than an order of magnitude.
Anthology ID:
2026.emnlp-industry.153
Volume:
Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing: Industry Track
Month:
October
Year:
2026
Address:
Budapest, Hungary
Editors:
Pepa Atanasova, Gholamreza Haffari, Minghan Wang
Venue:
EMNLP
SIG:
SIGDAT
Publisher:
Association for Computational Linguistics
Note:
Pages:
2591–2607
Language:
URL:
https://aclanthology.org/2026.emnlp-industry.153/
DOI:
Bibkey:
Cite (ACL):
Cen Zhao, Peng Wang, Chuan Shi, Yufeng Zhang, Ying Lyu, Wanmeng Ren, Robert Xue, Claire Cheng, and Yashar Mehdad. 2026. From Monolithic Blending to Agentic Orchestration: Dynamic Response for Conversational Assistants at Scale. In Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing: Industry Track, pages 2591–2607, Budapest, Hungary. Association for Computational Linguistics.
Cite (Informal):
From Monolithic Blending to Agentic Orchestration: Dynamic Response for Conversational Assistants at Scale (Zhao et al., EMNLP 2026)
Copy Citation:
PDF:
https://aclanthology.org/2026.emnlp-industry.153.pdf