Results
Qwen 3.6 Plus and Qwen 3.5 35B are both from Alibaba's Qwen family. Qwen 3.6 Plus is the commercial API tier. Qwen 3.5 35B is the open-weights variant.
Both models received the same Three.js brief, the same assets, and the same agentic workflow.
- Qwen 3.6 Plus: passed in 79 min 15 s. 2,610 lines across 15 files. 4 debug iterations.
- Qwen 3.5 35B: reached the 60-minute ceiling. 850 lines across 7 files. 8 debug iterations, still in the debug loop.
Time breakdown
Qwen 3.6 Plus spent 70.5 minutes in initial development and 8.7 minutes in debug. The initial phase is the longest of any model in this round. Total: 79 min 15 s.
Qwen 3.5 35B spent 24.2 minutes in initial development and 35.8 minutes in debug before the timeout. Debug iterations: 8. Commit history shows active fixes during the debug phase.
Per-model breakdown
Qwen 3.6 Plus front-loaded reasoning into initial development and produced a compiling build with minimal debug work. 4 debug iterations were sufficient to pass.
Qwen 3.5 35B produced a shorter initial build and entered the debug loop earlier. 8 iterations landed within the budget without clearing all failures before the 60-minute ceiling.
Methodology
We gave both models the same Three.js brief, the same input assets, and the same agentic workflow. Wall-clock time was capped at 60 minutes for the open-weights run and allowed to run to completion for the commercial run. Line counts are measured across files in the final commit. Debug iterations count the number of automated fix cycles after the first build attempt.
Takeaways
Qwen 3.6 Plus completed the brief at 79 min 15 s with 2,610 lines. Qwen 3.5 35B did not complete within 60 minutes and produced 850 lines before the ceiling.
For self-hosted Qwen 3.5 35B on a brief of this size, two options apply: decompose the task into smaller steps that fit the model's reasoning horizon, or raise the timeout above 60 minutes. For the commercial Qwen 3.6 Plus API, the brief completes, at a cost of longer wall-clock time than other commercial models in this round.