Title: Looking for guidance and collaborators to train an open LLM project (“Hyperion”)

Hi everyone,

I’m currently exploring the process of training and fine-tuning an open-source LLM, and I’m looking for guidance from people with hands-on experience — as well as potential collaborators who might be interested in developing something together.

The working name for the project is Hyperion. At a high level, the goal is to build a practical, efficient language model that prioritises clarity, reasoning, and real-world usability over raw scale. This is very much a learning-forward and iterative project rather than a claim to reinvent foundation models.

Areas I’m actively looking for advice on include:

  • Choosing an appropriate base model (e.g. LLaMA-derived, Mistral-style, etc.)

  • Fine-tuning vs. training from scratch trade-offs for small teams

  • Dataset curation strategies (quality vs. quantity, synthetic data, filtering)

  • Hardware constraints and realistic training setups

  • Evaluation methods beyond simple benchmarks

Longer-term, I’m also interested in forming a small, open, research-minded team — people who enjoy experimentation, transparency, and thoughtful model design. If you’ve worked on open LLMs, training pipelines, or dataset tooling (or are learning and want to contribute), I’d love to hear from you.

I’m happy to share more detail about the project direction as it solidifies, and I’m very open to feedback, reality checks, and course-corrections from those who’ve been down this road already.

Thanks in advance — and appreciation to the Hugging Face community for being one of the best places to learn this stuff properly.

— John

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You’re better off working on building wrappers or new layers for AI because there are quite a lot of people trying to profit from people trying to do what you want to do.

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For now guide. Detailed version is here.


You are better off building the system layers first, then doing targeted post-training (SFT → preference tuning). Training a new base model from scratch is usually the worst ROI path for a small team unless “pretraining research” is explicitly the goal.

Below is a practical roadmap that matches “clarity, reasoning quality, reliability, real-world usability” and small-team constraints.


1) First reality check: what’s feasible for a small team

Training from scratch (pretraining)

Pretraining is dominated by (1) data scale + legal provenance, (2) compute scale, (3) infra and reproducibility. The compute-optimal scaling literature shows you generally need a lot of tokens and training runs to land a strong base model, and the “optimal” tokens increase with model size. (arXiv)

Small teams can absolutely pretrain tiny models as an educational exercise, but if your goal is a usable assistant, the best leverage is elsewhere.

Post-training (fine-tuning/alignment)

Post-training is where small teams can win:

  • You start from a strong open-weights base.
  • You adapt behavior (clarity, tool discipline, refusal calibration).
  • You do it with tractable hardware using parameter-efficient methods.

Methods like LoRA and QLoRA exist specifically to make this feasible by reducing trainable parameters and memory. (arXiv)


2) Base model choice: how to choose and a short shortlist

Pick base models the way you pick an engine: license + serving + context + ecosystem.

Selection criteria that matter in practice

  1. License posture
  • If you want fewer surprises for redistribution and commercial use, Apache-2.0 style licensing is simplest.
  • “Open weights” models sometimes have custom license terms that create obligations or restrictions.
  1. Serving compatibility
  • Decide early what you will serve with (common choices: vLLM, llama.cpp, TGI).
  • If you want structured outputs (JSON schema, regex, grammars), check backend support. vLLM supports multiple guided decoding modes including JSON schema. (docs.vllm.ai)
  1. Context length and KV-cache cost
  • Long context is not free. It increases KV cache memory pressure and often becomes the bottleneck before raw FLOPs. vLLM’s docs explicitly call out controlling context length and batch sizing to manage memory. (docs.vllm.ai)

Practical late-2025-ish shortlist (small-to-mid models)

Apache-2.0 options (cleaner for “open” projects):

  • Qwen2.5-7B-Instruct (Apache-2.0; strong generalist; long-context support is a focus). (Hugging Face)
  • Mistral-Nemo-Instruct-2407 (12B) (Apache-2.0; 128k context; positioned as a drop-in for “small model” deployments). (Hugging Face)

Custom-license options (still popular, but read the terms carefully):

  • Llama 3.1: the license includes redistribution/attribution obligations and a large-scale MAU commercial term (the “>700M monthly active users” clause). (Hugging Face)
  • Gemma: distributed under Google’s terms with specific distribution conditions and a prohibited use policy reference. (Google AI for Developers)

A pragmatic recommendation

Pick two bases:

  • Fast/small (developer experience, iteration speed): ~7B–8B
  • Better reasoning (still tractable): ~12B–14B

Then force both through the same orchestration, tool schema, and evaluation harness so the base model is swappable.


3) Fine-tuning vs training from scratch: what to do first

Recommended order for a small team

  1. System reliability layer (orchestration, context policy, tool execution, schema validation, tracing)
  2. SFT (supervised fine-tuning) on a small, high-quality set aligned to your rubric
  3. Preference tuning (DPO-style) driven by failure cases

Why this order:

  • Wrappers can enforce many constraints deterministically (schemas, tool execution verification).
  • Training is best used for behaviors the wrapper cannot reliably enforce (decision policies, grounding habits, refusal calibration).

What to use for post-training

  • LoRA: add small trainable low-rank adapters instead of updating all weights. (arXiv)
  • QLoRA: LoRA on top of a 4-bit quantized base; the original paper shows feasibility even for very large models under constrained VRAM. (OpenReview)
  • DPO (Direct Preference Optimization): aligns to pairwise preferences without the full RLHF reward-model pipeline complexity. (OpenReview)

4) Dataset strategy: quality beats quantity, and provenance matters

Data for post-training (SFT + preference)

For your goals (clarity, reasoning, usability), you want:

  • Rubric-tagged instruction conversations
  • Failure-trace mining (collect real failures from your runtime and turn them into training examples)
  • Length-controlled preference pairs so “verbosity doesn’t auto-win”

If you ever do continued pretraining (optional)

Use large open corpora mainly as a reference point and for controlled experiments:

  • FineWeb (web-derived, processed/deduplicated; created as a high-quality pretraining dataset artifact). (Hugging Face)
  • Dolma (3T tokens, documented mixture; released for open pretraining research). (arXiv)
  • RedPajama-V2 (web-only dataset with quality signals and deduped subsets). (arXiv)

Synthetic data: use it, but cap it

Synthetic data is useful for:

  • Expanding coverage of rare formats (tool calls, structured outputs)
  • Creating preference pairs at scale

But it can also create self-reinforcing artifacts if it dominates training. Use “real anchors” and hard validation gates.


5) Hardware and serving constraints: plan around VRAM and KV-cache

Training

  • PEFT saves memory because you avoid storing optimizer states and gradients for the full base model. (Hugging Face)
  • 4-bit quantization with bitsandbytes is a common path for QLoRA-style workflows. (Hugging Face)

Rule of thumb: if you cannot afford multiple GPUs, bias toward:

  • smaller base models
  • LoRA/QLoRA
  • shorter training contexts first, then scale context later

Inference

  • Long context can make the KV cache your primary scaling pain.
  • vLLM explicitly documents memory controls (max context, batch sizing, GPU memory utilization). (docs.vllm.ai)
  • Techniques like quantized KV cache exist to reduce KV storage memory. (docs.vllm.ai)

If your product needs reliable structured outputs, verify that your inference stack supports guided decoding (vLLM does). (docs.vllm.ai)


6) Evaluation beyond “one benchmark”: build a layered scorecard

You want evaluations that match your target behaviors.

Layer A: deterministic validators

  • JSON schema validity
  • tool-call argument validation
  • citation/grounding checks (if using retrieval)
    These are cheap, fast, and regression-friendly.

Layer B: standardized task suites

  • lm-evaluation-harness gives broad coverage across classic NLP/LLM tasks and is actively maintained/releases are tracked. (Zenodo)

Layer C: judge-based, debiased comparisons

  • MT-Bench / Chatbot Arena judge methodology is widely referenced, with analysis of judge vs human agreement. (arXiv)
  • AlpacaEval 2 emphasizes length-controlled win rates to reduce verbosity bias. (GitHub)
  • Arena-Hard-Auto is designed to correlate with Chatbot Arena-style signals. (GitHub)

Layer D: tool and agent evaluations (if you support tools)

  • ToolBench / ToolLLM provides data and an eval framing for tool use. (arXiv)
  • AgentBench evaluates LLMs as agents in interactive environments. (arXiv)
  • If you care about “real coding usefulness,” SWE-bench is a strong reality check because it is grounded in real repo issues and tests. (GitHub)

Security regression pack

If you do retrieval or tools, prompt injection is not optional. OWASP’s LLM Top 10 is a decent baseline threat checklist. (OWASP)


7) Wrappers/layers vs “new base model”: the highest-leverage decision

If the goal is a usable assistant system, prioritize:

  1. Orchestration + context policy (windowing, summarization slots, token budgets)
  2. Tool execution with verification (no fake tool traces)
  3. Structured outputs with bounded repair loops
  4. Tracing/observability (prompt hashes, tool I/O, validator results, latency, token counts)
  5. Evaluation harness that gates releases

Then do targeted post-training to improve:

  • tool selection policies
  • refusal calibration
  • clarity and reasoning style consistency
  • grounding discipline

This approach also makes base models swappable without rewriting your product surface.


8) Forming a small open team: what attracts serious contributors

Make the project legible and testable:

  • A public “north star” spec (3–5 workflows, success criteria, non-negotiables)

  • A reproducible eval harness that anyone can run

  • A clear data policy (sources, licenses, dedup strategy, what you will not use)

  • A contribution ladder:

    • add eval cases
    • add tools and validators
    • improve training recipes
    • ship reference adapters

A surprisingly effective recruiting move is: “Here is the eval suite. Here are the current failures. Pick one.”


Curated references worth keeping open


Summary

  • Build the assistant system layer first. It produces reliability and the best training signals.
  • Start from two base models (small + mid) and standardize serving + eval so swapping is easy.
  • Do LoRA/QLoRA SFT, then DPO-style preference tuning from real failures. (OpenReview)
  • Treat context length and KV cache as first-class deployment constraints. (docs.vllm.ai)
  • Use a layered eval scorecard and include security regression tests. (OWASP)

Dear John,

The strategic direction for Project Hyperion is technically sound. For a small team, prioritizing system reliability layers and post-training (SFT/DPO) is the only viable path. Pretraining from scratch is computationally prohibitive and largely dominated by entities with massive resources.

However, a realistic assessment of the landscape is necessary: the open-source LLM market is highly saturated, making direct monetization difficult. Consequently, the project’s primary utility is educational, offering high returns in systems engineering proficiency rather than immediate commercial viability.

Regarding your query on “evaluation methods beyond simple benchmarks”, this is where our roadmaps converge perfectly. We are currently hardening an LLM Security Firewall, and we have hit the limits of general-purpose embeddings in cross-cultural adversarial scenarios (e.g., detecting social engineering nuances in Japanese or Italian).

This presents a concrete interface for collaboration:

  1. The “Hyperion” Role (Your Stack): We have curated high-fidelity adversarial datasets (Red-Team logs) but lack the specialized models to detect them efficiently. Applying your SFT/DPO pipelines to fine-tune lightweight “Judge” models (e.g., based on Mistral-Nemo or Llama-3-8B) would be the perfect application of your “reasoning over scale” philosophy.

  2. The Integration (Our Stack): Our Orchestrator acts as the runtime environment. We can plug your fine-tuned models directly into our voting ensemble. This gives you immediate, real-world feedback on your model’s performance against active attack vectors—far more valuable than static leaderboard metrics.

If you are interested in moving beyond generic chatbots and focusing on AI Safety & Governance layers, let’s discuss. We can provide the architectural constraints and the “hard” data; you provide the training expertise.

To succeed, focus on parameter-efficient fine-tuning (QLoRA) of Apache-2.0 bases and a rigorous evaluation stack like the one we are building.

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  1. Base Models: Avoid older architectures. Focus on the 7B–12B parameter class (e.g., Mistral-Nemo or Llama-3 derivatives). These offer the highest “reasoning-per-watt” ratio and fit within the inference budgets of modern orchestration layers. Apache 2.0 licensing is non-negotiable for real utility.

  2. Training Strategy: Do not train from scratch. The compute-to-utility curve is brutal. Instead, focus on Continued Pre-Training (CPT) for domain adaptation, followed by SFT (Supervised Fine-Tuning) for instruction following. This is where small teams can actually beat foundation models in niche tasks.

  3. Data Curation: Quality > Quantity. In our security work, we found that 1,000 high-quality, verified “hard negatives” outperform 100,000 generic samples. Synthetic data is viable only if rigorously filtered by a strong “Teacher” model.

  4. Hardware: Don’t build; rent. For fine-tuning (QLoRA/LoRA), cloud-based A100/H100 clusters (via RunPod/Lambda) are far more cost-effective than maintaining on-premise hardware.