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What 36 domain-trained open-weight models show about training your own

Anurag Dubey · 21 October 2026 · 12 minute read

In October 2026 Deel published how it trained Pangaea K1, a 9B open-weight model, on its internal knowledge base of employment rules across more than 150 countries. On Deel's own evaluation the trained model scored 70, up from 19 for the base it started from, and answered in a median 7.7 seconds. Eight frontier models given search over the same knowledge base scored between 52 and 75 and took 13 to 28 seconds.

Deel is one team among many doing this. We collected 35 other open-weight models that started from an existing base model and were trained further for one domain or task, and recorded the same facts for each: what it was built on, which training stages it went through, how much data it saw, and what it gained over its starting point. Every figure comes from a model card, paper or launch post, checked on 21 October 2026, and every source is listed at the end.

How much training added

Points gained over the model each one started from, on its own headline benchmark

  • Pangaea K1HR / Employment, weights not public
    +51
  • Lawma-8BLegal
    +37.7
  • Foundation-Sec-8B-ReasoningCybersecurity
    +22.2
  • MedGemma 1.5 4BMedical
    +18.4
  • Sarvam-MIndic languages
    +16
  • DianJin-R1-32BFinance
    +14.1
  • MedGemma 27BMedical
    +12.8
  • MiMo-V2.6-Distill-Qwen-9BCoding / Agents
    +12.6
  • Qwen-Open-Finance-R-8BFinance
    +10
  • Fin-R1Finance
    +9.6
  • Fino1-8BFinance
    +9.6
  • OmniCoder-9BCoding / Agents
    +9
  • Foundation-Sec-8BCybersecurity
    +9
  • SaulLM-141B-InstructLegal
    +8?
  • Intern-S1Science
    +7.6
  • Apertus-70B-MeditronFOMedical
    +6.5
  • LLama-3-8B-TeleTelecom
    +5
  • Index-Translate-9BTranslation
    +4.7
18 of the 36 models report a score for their own base model. Each uses its own benchmark, so bars compare size of gain, not ability. The dashed bar is Pangaea K1 on Deel's internal evaluation; its weights are not public. SaulLM's figure is read from a chart in its paper. Figures as published, checked 21 October 2026.

Key findings

  • Qwen is the default base model. 17 of the 36 models start from a Qwen model, including all four 9B releases of 2026.
  • Supervised fine-tuning is the common stage. 22 models report it. Nine add reinforcement learning and eight run continued pretraining on domain text. Only Bilibili's Index-Translate-9B reports all three.
  • Training data ranges from thousands of examples to trillions of tokens. DeepSWE used about 4,500 problems. Intern-S1 used about 5 trillion tokens.
  • Narrow tasks gain the most. Lawma-8B went from 42.6% to 80.3% on 260 legal classification tasks. Broad domains such as medicine and finance typically gained 6 to 14 points.
  • Half the field shows no before and after. 18 models report a score for their own base model, and 12 disclose a token count.

The 36 models

Grouped by domain, newest first. Training stages: CPT is continued pretraining on domain text, SFT is supervised fine-tuning on example answers, RL is reinforcement learning. "Gain over base" is the headline improvement, in benchmark points, over the model it was trained from.

Figures as reported by each publisher, checked 21 October 2026. "c." marks a date taken from a repository creation date, the model name or a third-party site. Pangaea K1 weights are not public and it is listed for reference.
ModelTaskReleasedBase modelSizeStagesDomain training dataGain over baseHeadline result
Law and finance
Ling-3.0-flash-FinAnt Group (inclusionAI) · FinanceFinancial research: grounded search, multi-document reasoning, valuation, reportsc. Sep 2026Ling-3.0-flash124B (5.1B active)CPTNot disclosedNo base scoreCard shows results only as a chart; third-party figure: Finance Agent v2 54.9% at $0.04/task
Qwen-Open-Finance-R-8BOVHcloud / DragonLLM · FinanceFinancial analysis, compliance, investment research, financial translation (EN/FR/DE)Nov 2025Qwen3-8B8BSFT~2.03M samples; tokens not disclosed+10 acronymsOnly published 8B result: financial acronyms accuracy EN 0.49 vs 0.39 base, FR 0.28 vs 0.17
DianJin-R1-32BAlibaba Cloud (Qwen-DianJin) · FinanceFinancial reasoning and compliance checking (Chinese)Apr 2025Qwen2.5-32B-Instruct32B (also 7B)SFT + RLNot disclosed+14.1 avg5-benchmark avg 82.1 vs 68.0 base (DeepSeek-R1 79.0); compliance (CCC) 96.0 vs 56.5
Fin-R1SUFE AIFLM Lab · FinanceFinancial reasoning, calculation, compliance, risk, ESGMar 2025Qwen2.5-7B-Instruct7BSFT + RL~60K chain-of-thought samples, then RL+9.6 avg5-benchmark avg 75.2 vs 65.6 base (DeepSeek-R1 78.2); FinQA 76.0 vs 60.0
Fino1-8BTheFinAI · FinanceFinancial math reasoning (FinQA)Feb 2025Llama-3.1-8B-Instruct8BSFT + RL~5.5K reasoning paths (unit unclear)+9.6 avg4-benchmark avg 50.8 vs 41.2 base (GPT-4o 61.0); XBRL-Math 82.2 vs 62.2
SaulLM-141B-InstructEquall · LegalLegal text understanding and instruction followingJul 2024Mixtral (8x22B)141B (also 54B)CPT + SFT500 to 540B legal tokens (paper inconsistent); ~1M instructions+8 LegalBench?LegalBench-Instruct 75.3 vs ~67.4 Mixtral-141B, GPT-4 73.4 (read from a figure; pairing uncertain)
Palmyra-Fin-70B-32KWriter · FinanceLong-context financial analysisJul 2024Palmyra-X-00370BNot disclosedNot disclosedNo base scoreCFA Level III sample test 73% (pass ~60%, GPT-4 33% per Writer). No base score
Lawma-8BDominguez-Olmedo et al. · Legal260 US legal classification tasksJul 2024Llama-3-8B-Instruct8BSFT500K+ examples, ~2B tokens+37.7260 legal tasks mean accuracy 80.3% vs 42.6% base (GPT-4 62.9%)
Medicine and science
Apertus-70B-MeditronFOEPFL LiGHT · MedicalClinical question answering (MedQA, MedMCQA, HealthBench)May 2026Apertus-70B-Instruct-250970BSFT~601K examples (~150M tokens)+6.5 avg5-benchmark medical avg 51.4 vs 44.9 base; MedQA 68.6 vs 60.6; HealthBench Hard 40.1 vs 32.3
Baichuan-M3-235BBaichuan · MedicalClinical consultation, diagnosis support, reducing hallucinationFeb 2026Qwen3-235B-A22B235BSFT + RLNot disclosedNo base scoreHealthBench-Hard 44.4; claims to beat GPT-5.2 and top SCAN-bench, no comparison numbers
MedGemma 1.5 4BGoogle · MedicalCT/MRI, histopathology, chest X-ray comparison, lab reports, EHR QAJan 2026Gemma 34BNot disclosedNot disclosed+18.4 MedQAMedQA 69.1 vs 50.7 base Gemma 3 4B; EHRQA 89.6 vs 70.9; MRI accuracy 64.7 vs 51.1. Some tasks fell vs MedGemma 1
Intern-S1Shanghai AI Lab · ScienceChemical structures, protein sequences, synthesis planningAug 2025Qwen3-235B MoE + InternViT241BCPT~5T tokens, of which 2.5T+ scientific+7.6 ChemBenchChemBench 83.4 vs 75.8 base Qwen3-235B; MatBench 75.0 vs 52.1; SmolInstruct 51.0 vs 28.7. Trails Grok-4 on GPQA
Baichuan-M2-32BBaichuan · MedicalMedical reasoning and clinical decision supportAug 2025Qwen2.5-32B32BNot disclosedNot disclosedNo base scoreHealthBench 60.1 (gpt-oss-120b 57.6); HealthBench-Hard 34.7. No base score
ether0FutureHouse · ChemistryMolecular design and chemistry reasoning across 375 tasksJun 2025Mistral-Small-24B24BSFT + RL640,730 chemistry problems (plus SFT)No base scoreReaction prediction 70% on own held-out set (retrained Molecular Transformer <30%); multiple-choice 50.1% vs o1 52.2%
MedGemma 27BGoogle · MedicalMedical text QA and reasoningMay 2025Gemma 3 27B27BNot disclosedNot disclosed+12.8 MedQAMedQA 87.7 vs 74.9 base Gemma 3 27B; MedMCQA 74.2 vs 62.6; MedXpertQA 26.7 vs 15.7
II-Medical-8BIntelligent Internet · MedicalMedical reasoning and QAMay 2025Qwen3-8B8BSFT + RL555K+ samplesNo base score10-benchmark medical avg 70.5 (HuatuoGPT-o1-72B 71.1); MedQA 87.8. No base score
Code, maths and security
MiMo-V2.6-Distill-Qwen-9BXiaomi · Coding / AgentsCoding, agent tasks and cybersecurity; base for agentic RL researchc. Sep 2026Qwen3.5-9B9BSFT27.2B tokens trained (from a 77.4B-token mix)+12.6 SWE-ProSWE-Bench Pro 44.6 vs 32.0 base; Terminal-Bench 2.1 37.1 vs 27.0; SWE-Bench Verified 61.1 vs 60.0
OmniCoder-9BTesslate · Coding / AgentsAgentic coding: software engineering, tool use, terminal tasksc. Mar 2026Qwen3.5-9B9BSFT425K+ agent trajectories (LoRA); tokens not disclosed+9.0 T-BenchTerminal-Bench 2.0 23.6 vs 14.6 base; GPQA Diamond 83.8 vs 81.7 base
Qwen3-Coder-NextAlibaba Qwen · Coding / AgentsSoftware-engineering coding agentFeb 2026Qwen3-Next base80B (3B active)CPT"trillions" of tokens incl. ~600B repo-level; ~800K agent tasksNo base scoreSWE-Bench Verified 71.3 (Claude Opus 4.5: 79.0); SWE-Bench Pro 42.7; Terminal-Bench 2.0 36.2. No base score
Foundation-Sec-8B-ReasoningCisco Foundation AI · CybersecuritySecurity reasoning and instruction followingJan 2026Foundation-Sec-8B (Llama-3.1-8B)8BCPT (in parent model) + SFTNot disclosed+22.2 CTI-RCMCTI-RCM 75.3 vs 53.1 Llama-3.1-8B (GPT-5-Nano 67.2); CTI-MCQA 69.1 vs 60.7; HarmBench 93.0% vs 62.8%
OpenReasoning-Nemotron-32BNVIDIA · Math / Code / ScienceCompetition math, code and science reasoningJul 2025Qwen2.5-32B32BSFT~5M DeepSeek-R1 responsesNo base scoreAIME25 84.0; LiveCodeBench v6 70.2; GPQA 73.1. No base or comparison scores
Devstral-Small-2507Mistral AI · Coding / AgentsAgentic software engineering across codebasesc. Jul 2025Mistral-Small-3.1-24B-Base24BNot disclosedNot disclosedNo base scoreSWE-Bench Verified 53.6% (Devstral 1.0: 46.8%, DeepSWE: 42.2%). No base score
DeepSWE-PreviewAgentica / Together AI · Coding / AgentsSoftware-engineering agent (59% SWE-Bench Verified)c. Jul 2025Qwen3-32B32BRL~4.5K problems, 200 stepsNo base scoreSWE-Bench Verified 42.2% pass@1, 59% best-of-16. Validation rose 23→42% during RL
Devstral-Small-2505Mistral AI · Coding / AgentsAgentic software engineeringc. May 2025Mistral-Small-3.1-24B-Base24BNot disclosedNot disclosedNo base scoreSWE-Bench Verified 46.8% (Claude 3.5 Haiku 40.6%, GPT-4.1-mini 23.6%). No base score
Foundation-Sec-8BCisco Foundation AI · CybersecurityGeneral security knowledge (base model)Apr 2025Llama-3.1-8B8BCPT~5.1B tokens+9.0 CTI-RCMCTIBench-RCM 72.0 vs 63.0 base (Llama-3.1-70B 70.9); SecBench 72.3 vs 73.5 (slightly lower); MMLU dipped
SWE-agent-LM-32BPrinceton & Stanford (SWE-smith) · Coding / AgentsSoftware-engineering agent for SWE-agentApr 2025Qwen2.5-Coder-32B-Instruct32BSFT5K trajectoriesNo base scoreSWE-Bench Verified 40.2% pass@1
OpenMath-Nemotron-32BNVIDIA · MathMath reasoning (AIMO-2 winning solution)Apr 2025Qwen2.5-32B32BSFTOpenMathReasoning dataset (5.68M rows)No base scoreAIME24 78.4 (DeepSeek-R1 79.1); HMMT-24-25 59.7 (DeepSeek-R1 53.0), with code execution
Business, telecom and language
Pangaea K1Deel · HR / EmploymentAnswering employment, payroll and compliance questions across 150+ countries from memoryOct 20269B open-weight model, not named9BCPT + SFT + RL (started)~1.2B-token corpus, 2 passes; teacher-distilled SFT+51 (Deel eval)Deel fact-level eval 70 vs 19 base; search-equipped frontier models 52 to 75; 7.7 s vs 14.8 to 28.4 s median
Clef-FlashCloudflare · Agent decisionsRouting tickets, blocking requests, escalation and human handoff decisions over text, JSON, images or videoOct 2026Qwen3.5-9B9BNot disclosedNot disclosedNo base scoreBANKING77 macro-F1 90.9 (Clef 27B: 94.2); customer-service workflow exact actions 77.0; 38.8 ms median latency. No base score
Index-Translate-9BBilibili · TranslationTranslation across 150 languages with terminology, style and format controlSep 2026Qwen3.59BCPT + SFT + RL167.77B tokens (mid-training); SFT/RL size not disclosed+4.7 COMETFLORES COMET-22 0.879 vs 0.832 base (TranslateGemma-12B 0.873); WMT24++ 0.860 vs 0.807; instruction-following 0.821 vs 0.061 base
OTel-2.0-LLM-31B-ITOpen Telco (AT&T, GSMA, MLCommons) · TelecomTelecom knowledge and instruction followingJul 2026Gemma 4 31B-IT31BSFT~440B training tokens (from a 15B-token raw telecom corpus)No base scoreUnnamed 1,700-question telecom eval 91.9% micro. No base or comparison scores
Qwen-MarketingMarketeam · MarketingMarketing copy, campaign ideas, brand-voice textc. Jun 2025Qwen3-8B8BSFT10B+ tokens of marketing dataNo base scoreNo results published; claims to beat GPT-4o on marketing prompts without numbers
Sarvam-TranslateSarvam AI · Translation (Indic)Document translation between English and 22 Indian languagesc. Jun 2025Gemma 3 4B-IT4BNot disclosedNot disclosedNo base scoreNo numeric results; LLM-judged >4.9/5 on 15 languages; preferred over larger models in a 100-document human eval
Sarvam-MSarvam AI · Indic languagesMultilingual chat and reasoning in Indian languagesc. May 2025Mistral-Small-3.1-24B-Base24BSFT + RLNot disclosed+16 MILU-INMILU-IN 0.75 vs 0.59 base (Gemma 3 27B 0.65); romanized Indic GSM-8K 0.82 vs 0.44; MMLU-IN 0.79 vs 0.64
LLama-3-8B-TeleAli Maatouk et al. · TelecomTelecom standards and technical knowledgeSep 2024Llama-3-8B8BCPT~2.5B tokens+5.0 Tele-EvalTele-Eval 29.6 vs 24.6 base; MMLU 61.6 vs 62.1 (general knowledge kept)
eCeLLM-MNingLab (Ohio State) · E-commerceInstruction following on e-commerce tasksFeb 2024Mistral-7B-Instruct-v0.27BSFTECInstruct, 264K rowsNo base scoreFamily-level: +10.7% in-domain, +9.3% out-of-domain over best baseline incl. GPT-4 Turbo

Qwen is the default starting point

Seventeen of the 36 models start from Qwen. In the 9B class the pattern is complete: Cloudflare's Clef-Flash, Bilibili's Index-Translate-9B, Xiaomi's MiMo-V2.6 distill and Tesslate's OmniCoder-9B all build on Qwen3.5-9B, which Alibaba publishes under Apache 2.0 in sizes from 0.8B to 122B. Deel has not named the base for Pangaea K1, though it is the same size.

Llama 3 and 3.1 account for five models, nearly all from 2024 and early 2025. Mistral and Mixtral account for six, four of them on Mistral Small 24B. Google's Gemma line carries four: both MedGemma releases, Sarvam-Translate and the Open Telco model, which is built on Gemma 4 31B.

If you are choosing a base today, the practical reason for Qwen's lead is the size ladder. One architecture at every scale lets a team prototype on 9B and move up without changing tokenizer, chat format or tooling.

Which training stages teams use

Three stages appear in the table, and they do different jobs. Continued pretraining keeps the model predicting the next word, on domain text instead of the open web; it is how a model takes in facts. Supervised fine-tuning trains it on example answers, which teaches it how to respond. Reinforcement learning rewards answers that pass a check, so it shows up where an answer can be verified: a calculation, a compliance verdict, a test suite.

Eleven models use fine-tuning alone. Seven follow it with reinforcement learning, and that pairing is now the standard recipe for reasoning in a domain: Fin-R1, DianJin-R1 and Fino1 in finance, II-Medical and Baichuan-M3 in medicine, ether0 in chemistry, Sarvam-M for Indian languages. DeepSWE skipped fine-tuning and used reinforcement learning alone.

Continued pretraining appears where the model has to hold a large body of knowledge: SaulLM on legal text, Intern-S1 on science, Foundation-Sec-8B on security, LLama-3-8B-Tele on telecom standards. Deel's write-up gives the reason in one line, citing a 2024 Google study: fine-tuning on facts the model does not already know makes it learn them slowly and hallucinate more. Facts go in during pretraining, and fine-tuning teaches the model what a good answer looks like.

How much data it takes

The amount depends on whether the model is learning a behaviour or a body of facts.

  • A behaviour, in thousands of examples. SWE-agent-LM-32B reached 40.2% on SWE-Bench Verified from 5,000 agent trajectories. DeepSWE reached 42.2% from about 4,500 problems over 200 reinforcement learning steps.
  • A domain's reasoning, in tens of thousands. Fin-R1 used about 60,000 worked examples and lifted FinQA from 60.0 to 76.0, ahead of DeepSeek-R1 at 71.0.
  • A company's knowledge, in billions of tokens. Deel turned a 69 million token knowledge base into a 1.2 billion token training corpus by restating each fact about a dozen ways, then trained for two passes. Foundation-Sec-8B used 5.1 billion tokens and LLama-3-8B-Tele 2.5 billion.
  • A whole field, in hundreds of billions or more. SaulLM trained on more than 500 billion legal tokens. Intern-S1 used about 5 trillion, over half of them scientific.

Deel's corpus is the useful reference point for a company. Its source material was small, and the multiplication came from rewriting: research it cites shows a model can memorise a text and still answer 0% of questions about it unless it has seen the facts restated in varied forms.

What the gains look like

The largest gains come where the task is narrow and the base model was weak at it. Lawma-8B nearly doubled its base on legal classification and beat GPT-4 (62.9%). Cisco's Foundation-Sec-8B-Reasoning gained 22.2 points on threat-intelligence root-cause mapping over Llama-3.1-8B. Sarvam-M gained 16 points on an Indian-language knowledge benchmark and nearly doubled its base on maths word problems written in romanized Indian languages.

Broad domains move less. EPFL's Apertus-70B-MeditronFO gained 6.5 points averaged over five medical benchmarks, and Fin-R1 gained 9.6 averaged over five finance benchmarks. DianJin-R1-32B is the outlier in finance: 14.1 points on average, and 96.0 on a compliance checking benchmark where its base scored 56.5 and DeepSeek-R1 scored 67.5.

Several small models match or beat far larger general ones on their own task. Fin-R1 at 7B beats DeepSeek-R1 on FinQA, though DeepSeek-R1 still leads on the five-benchmark average (78.2 against 75.2). Pangaea K1 answered from memory within five points of the best search-equipped model and in about half the time.

What training costs in general ability

Training hard on one domain can wear away what the model knew before. The table shows it in small amounts. Foundation-Sec-8B dropped from 61.7 to 59.3 on MMLU and slightly on one security benchmark. LLama-3-8B-Tele slipped from 62.1 to 61.6 on MMLU. MedGemma 1.5 improved on most medical tasks but fell below MedGemma 1 on some, including PubMedQA.

The usual guard is replay: mixing general text back into training. Deel kept about 7.5% of its corpus as general text, citing research that even 1% measurably reduces forgetting, and added everyday tasks to its fine-tuning set for the same reason.

How to read these numbers

  • Every result is self-reported. None of the benchmark figures in the table has been independently reproduced.
  • Each model picks its own benchmarks. A 9-point gain on FinQA and a 9-point gain on Terminal-Bench say nothing about each other. Compare within a domain.
  • Agent benchmarks depend on the harness. SWE-Bench scores in the table come from OpenHands, SWE-agent and R2E-Gym setups, so they are close to like for like at best.
  • Some sources contradict themselves. Baichuan-M3's card claims 28 points over M2 on HealthBench-Hard where the two cards show about 10. SaulLM's paper gives its legal corpus as 500, 520 and 540 billion tokens in different places. Fino1's text and table give different base scores.
  • Disclosure is thin. Eight models do not describe their training method at all, among them Google's MedGemma, Mistral's Devstral and Cloudflare's Clef-Flash.

Where the gaps are

We found no open-weight model trained for HR or customer support with published results, and only one for marketing. Marketeam's Qwen-Marketing was trained on more than 10 billion tokens of marketing data from Qwen3-8B, and its card says no formal benchmark exists yet. Cloudflare's Clef-Flash comes closest on support: it routes and escalates tickets, scores 90.9 macro-F1 on BANKING77, and does not compare itself with its base.

The reason is visible in the table. Law, medicine, finance and code all have large public corpora and public benchmarks. A company's own operations have neither: the knowledge sits in its tickets, policies and systems, and the only test that matters is whether the model gets that company's cases right. Deel solved both halves itself, with tens of thousands of internal pages and a 601-question evaluation built from what its teams ask every day.

Frequently asked questions

What is a domain-trained open-weight model?

It is a language model whose weights are published for anyone to download, and which started from a general-purpose base model before being trained further on one field or task. Fin-R1, for example, is Qwen2.5-7B-Instruct trained on about 60,000 worked finance examples and then with reinforcement learning.

What is the difference between continued pretraining and fine-tuning?

Continued pretraining keeps the model predicting the next word on domain text, which is how it takes in facts, and usually runs to billions of tokens. Supervised fine-tuning trains it on example questions and answers, which teaches it how to respond, and often needs only thousands to hundreds of thousands of examples. Most of the models in this comparison used fine-tuning; eight also used continued pretraining.

Which base model is used most for domain training?

Qwen. 17 of the 36 models in this comparison start from a Qwen model, including every 9B release of 2026, which all use Qwen3.5-9B. Llama, Mistral and Gemma account for most of the rest.

How much data do you need to train a domain-specific model?

It depends on what the model has to learn. A new behaviour, such as working as a coding agent, has been trained from about 5,000 examples. A company knowledge base took Deel about 1.2 billion tokens of rewritten training text, built from 69 million tokens of source pages. Learning a whole field, as SaulLM did for law, ran to more than 500 billion tokens.

Do small domain-trained models beat frontier models?

On their own task, often. Lawma-8B scores 80.3% on 260 legal classification tasks against 62.9% for GPT-4, and Fin-R1 at 7B beats DeepSeek-R1 on FinQA. Outside their task they usually trail, and every result here is reported by the model's own publisher.

All sources (36 models)

Your systems already hold the knowledge.

Every model above began with domain data someone collected and cleaned. SynOS is the platform for AI built on your own systems, and what your agents do there accumulates on your own infrastructure in the shape a training set is built from.