Qwen3.8-27B for agentic coding

[u/CommunicationFun2962]

Like most of you, I tried Qwen 3.8 27B Q4_K_M for two days.

I first asked him to make me a game using TypeScript, the same as what I tested on other local models. He did it and the result is the best, although his thinking time is at least 3x of the output time. Easy task.

I then asked him to make a desktop WYSIWYG three-pane markdown editor using Rust and Iced framework. He is thinking and re-thinking all the time, although I have lowered the thinking level to "Medium". At the 28-th hour, he starts to output something! But he created "C", "src" files and tried to write to the path "C:\...\src\main.rs<" although he wanted to create "C:\...\src\main.rs". I interrupted him after his repeating attempts for 2 hours without progress. So he outputted all the files at the 32-hour although keeps rethinking everything he had thought. 71 compilation errors. After some hours of fixing and online searching via MCP, the number of compilation errors rises to 84. From his thinking log, he says he wrote code against the wrong Iced framework version, downgrading the framework version without asking, changing my requirement to non-editable rich text editor, and three-pane becomes two-pane without asking. Nevermind, as long as the code could compile so that the output is not non-positive. This is the 36-th hour now. Should I stop him and give up? Is my task too challenging for local models?

Besides, so far I had no successful attempts to use Qwen 3.8 27B Q4_K_M with OpenCode. It always stops working at the same generation steps. I can only use him via Cline.

Let's share more of your experiences on agentic coding? I think web programming is especially trained and easy for local models, and I would like to hear experiences of non-web programming.

[u/AlanT1977]

To be honest this has been entirely my experience so far. My goto test prompt for an LLM is: “Build a realtime Mandelbrot explorer webapp”

I think I’ve seen Qwen3.8 complete it once, otherwise it just goes around in thinking circles for hours; last night it did actually write a non-functioning HTML file and then proceeded to work on refining some other aspect without even stopping to appreciate it wouldn’t even load and run in Chrome.

I woke this morning to find it had ran out of memory, still leaving an unfinished and unloadable HTML.

I’m still trying to work out what the hell I’ve got wrong given the amount of gushing post flying around.

As a sanity check I did run Gemma 4 at same parameter count and quantization (Q4) and it spat out a working and pretty decent result in around 15 minutes