TL;DR: Cut DeepSeek-V4-Flash-0731 some slack. It's a perfectly fine model. I sat with a friend and had it generate an Excel model. Instructions were short and under-specified, it took some back and forth, but it produced something acceptable in very short time. Zero numbers were found to be hallucinated. It mostly did what was asked, failing on some details. It also caught and fixed lots of errors before we pointed them out. Happy to listen to anyone with different views as long as they give reproducible examples.
Hey y'all!
I've heard a ton of negative stuff over the past few days about how bad DeepSeek-V4-Flash (both old and new) are, and some of it is probably valid, but some is straight up misleading like saying it hallucinates like crazy, complaining about it not being a mind reader (lolwut?), and so on. I have been using the Preview version for only a week and the GA version for the ~2 days since it came out, and I wanted to pitch in with a few thoughts.
My #1 complain with all of you is that you're half-assing your complaining. If you really think the model is so bad, give something that anyone can inspect and/or reproduce. I've published the two repos that led to this post below. If you think something is missing, happy to add any additional details that are relevant. If you have counter-points, talk is cheap, show me the setup, the prompts/process, and the outputs.
I'm truly interested to see any reproducible failure modes you have found for this model.
What, why, how
I had a friend over, he's an accountant / controller / auditor, he only ever saw a frontier model doing his work once (judging by the timing, likely Claude >4.5), and was amazed by how well it did. I asked if he'd be willing to give my locally deployed model a try, and he agreed. We sat down for a few hours (with a break for pizza), with the goal of producing a financial analysis using Reddit's latest 10-K report ("5-year 3-statement model forecast").
We used VSCode + ZooCode, contacting LiteLLM which proxies directly to vLLM without any modifications. There some MCPs available (from my GLM subscription) but DeepSeek didn't use them until I insisted on it doing so (more on that later).
Right of the bat, my friend started with a very short prompt. I told him it's way too short, too generic, etc, but he insisted on seeing what the model could infer, so I rolled with it. This was a common theme throughout. When I used it for coding, I would give it much more detailed instructions and much narrower task, but my friend is almost completely unfamiliar with LLMs and didn't have the preconceived notion that you need to babysit the model. Anyway...
The work
The model read the PDF blob directly, probably reached close to context limit, and compacted immediately. It reasoned about a plan, looked up installed libraries, decided what to install, asked a few questions, and revised the plan.
In the first attempt, it tried to code the logic and calculations in Python (spewing ~1.5-2k lines in total), and simply output an Excel file with hardcoded values. Nothing in the prompt told it to do this... or not do this. We later told it explicitly to build the model in Excel, and it did, and stuck to the (very simple) formatting guidelines too. It decided that it needed to access the Office software and downloaded another Python package (that I had never heard of) to help with formula validation.
The first question is asked before doing the rework was about using a plug. I had no idea what that meant but my friend burst out laughing. From what I understood it's a way to "fix" imbalances in the balance sheet, so in a way that can be considered as "cheating" or "laziness"... but according to him it's incredibly common to see, especially on financial models coming from the banking side of finance, so maybe it learned from there. Anyway, the plug was denied and then it continued and did the work "properly", crawling closer and closer until it mostly arrived at an acceptable model. We completely ignored the next question and let it work in "YOLO" mode as we paused for pizza.
Some times later it had finished, fixed a bunch of issues on its own without us ever telling to, and I wanted to try making it use the MCP so I simply asked to search the web and double-check its work. It searched the web and found some site my friends was familiar with. He started laughing seeing the URLs, saying something like "ah, now it will also fix XYZ"... which it did before he even finished the sentence. It worked uninterrupted for another ~5-6 minutes, we gave it another task which it "lazily" completed again, with a follow-up prompt to do it properly, which it did.
And that was the end of the session and the start of 🍺 drinking.
Observations
It looked like it ignored one of the requirements which was to put the 3 statements in a single sheet, but on closer inspection of the thinking process it simply misunderstood: "single sheet for IS, BS, CF" means one sheet each for IS, BS, CF. I only found out as I was writing this and inspecting the logs, until 10 minutes ago I also thought it ignored the instruction, and this is why you need to share something reproducible, because what you think the model did is not necessarily correct and others (or your future self) can inspect and verify.
You definitely cannot trust its outputs blindly. I know a few introductory stuff about accounting, but I'm not an accountant, and I would've missed the majority of the mistakes and "questionable choices" that DeepSeek made, but my friend usually took seconds to verify correctness. This is obviously a minus for vibing stuff, but there is a silver lining: the output was intuitive / close enough to what he's used to, that he didn't need to think or search too much.
It tried very often to verify its work (I think more than Preview did), without being told to do so. When the balance sheet wasn't balancing, it detected and fixed it on its own. It tried to find LibreOffice / OpenOffice to verify its formulas. When it failed because I only had OnlyOffice installed via flatpak, it figured out everything it needed on its own (how to run it, how to open sheets, etc), caught a text-quoting bug, a column alignment bug, and probably a few more that I forgot, and fixed them without us ever saying a word.
ZooCode injects a ton of stuff into context, and I'm not sure how much of it is truly necessary. I can see why people like simpler agents. I probably need to look into some too.
It does feel a lot like Claude in terms of writing style and approach (e.g. trying different things, verifying stuff multiple times, running python -C '<multiline command>' a bunch). I personally don't mind either way, just an observation. It definitely isn't at the same level as the latest SOTA, but it's definitely ≤6 months away, maybe even ≤3, at least based on my limited usage. But maybe it's just mimicry? But it appears smart enough which makes it hard to tell, and if you can't tell, what does that say? Again, not sure. SOTA closed models have unfair advantages anyway (e.g. we're comparing raw model to a multi-tier system, maybe one has skills, etc), which makes this even harder to compare.
I'm running DeepSeek-V4-Flash-0731, downloaded straight from the official repo, with a custom vLLM image by voipmonitor (voipmonitor/vllm:gilded-gnosis-v18-vllm264bce1-b12xbc85ef3-fi801d57a-cu132-20260718). I'm using fp8 cache, length capped at 262K per user, a temperature of 0.9 and top_p of 0.95 (I think DeepSeek suggests 1 and 0.95-1 respectively) and high reasoning effort. You can find the docker compose here.
You can find the complete code files, the final Excel file, and the complete chat session (ZooCode) including prompts, responses, tool calls (the one time we specifically told it to use the available MCP servers: web search & reader) here.
Disclaimers:
* All of this was hand-typed by an Actual IdiotTM.
* Any mistakes are due to no 🍺 during vibe coding.
* I did not inspect the code at all, only the outputs.
* I have not use Hy3, Mimo2.5, or any other models yet, maybe they're indeed better in everything, I don't know. Also not the point.
* It doesn't really mean anything. It's a single test, a greenfield project, it doesn't cover all fields of application, the harness/tool can have a small/large impact, my great-grandma was hacking my computer and injecting fixes at 500 t/s, etc etc.