https://cuigh.com/tags/engineering/ Recent content in Engineering on AI Pulse Hugo en-US Mon, 13 Jul 2026 09:51:14 +0800 https://cuigh.com/posts/gpt-5-6-sol-production-migration-2026/ Mon, 13 Jul 2026 09:51:14 +0800 https://cuigh.com/posts/gpt-5-6-sol-production-migration-2026/ Ploy publicly migrated its production agent from Claude Opus 4.8 to GPT-5.6 Sol and got the visible win — 2.2x faster, 27% cheaper, 0.970 vs 0.936 visual. The three engineering costs nobody talks about are: tool-argument overreach (GPT-5.6 fills all 25 optional params by default, 52%–64% of file reads came back empty), prompt-cache design cliff (partial-prefix implicit caching was dropped, zero hit without explicit key+breakpoint), and reasoning-replay mismatch (server-side item references break under multi-worker append-only input). Migrating a production agent is a stack migration, not a model swap.