FreshStack Evaluation Framework

Building Realistic Benchmarks for Evaluating Retrieval on Technical Documents

1University of Waterloo      2Databricks
NeurIPS 2025 Dataset & Benchmark Track
arXiv Code Dataset OpenReview Twitter Leaderboard BibTeX
TL;DR FreshStack is a holistic framework for building realistic & challenging RAG benchmarks from community-asked questions and answers on niche and fast-growing domains.
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🏆 FreshStack Leaderboard

Zero-shot retrieval on five niche technical domains (October 2024 snapshot), ranked by average Recall@50.

Model
Retriever
Bold best in column Underlined 2nd best α@10 alpha-nDCG · diversity & relevance C@20 Coverage · nuggets supported R@50 Recall · relevant docs retrieved Click headers to sort
Avg. (5) LangChain Yolo v7 & v8 Laravel 10 & 11 Angular 16, 17 & 18 Godot4
# Retriever Type Size Date α@10 C@20 R@50 α@10 C@20 R@50 α@10 C@20 R@50 α@10 C@20 R@50 α@10 C@20 R@50 α@10 C@20 R@50
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Evaluation setup

  • Zero-shot retrieval of relevant document chunks given a query, on FreshStack (October 2024 version).
  • Open-source & proprietary single-vector embedding models, plus late-interaction (multi-vector, ColBERT-style) retrievers.
  • Maximum sequence length of 2048 tokens for all models for both query and document.
📚

Five datasets

LangChainYolo v7 & v8Laravel 10 & 11Angular 16, 17 & 18Godot4

💡 Queries in FreshStack can be pretty long, so use a model that can handle code and long queries.

🚀

Submit your model

Add your results to leaderboard_data.json and open a pull request.

Open leaderboard_data.json
Paper

Abstract

We introduce FreshStack, a reusable framework for automatically building information retrieval (IR) evaluation benchmarks from community-asked questions and answers. FreshStack conducts the following steps: (1) automatic corpus collection from code and technical documentation, (2) nugget generation from community-asked questions and answers, and (3) nugget-level support, retrieving documents using a fusion of retrieval techniques and hybrid architectures. We use FreshStack to build five datasets on fast-growing, recent, and niche topics to ensure the tasks are sufficiently challenging. Existing retrieval models, when applied out-of-the-box, significantly underperform oracle approaches on all five topics, denoting plenty of headroom to improve IR quality.

Framework

How FreshStack Works

1

Corpus Collection

Automatically collect a corpus from code and technical documentation.

2

Nugget Generation

Generate nuggets from community-asked questions and answers.

3

Nugget-level Support

Retrieve documents with a fusion of retrieval techniques and hybrid architectures to support each nugget.

Step-by-step procedure followed in FreshStack for constructing evaluation datasets.

Analysis

Metrics vs. Model Parameters

Each point is a model with model parameters in the leaderboard (parameters in millions or billions, parsed from values such as 7B or 434M). The y-axis is the average across the five FreshStack domains for α@10 (alpha-nDCG@10), C@20 (Coverage@20) and R@50 (Recall@50). Models without a disclosed size (shown as “-” in the table) are listed below the plot and appear only in the release-date plot. Marker colors group model families (the family field in leaderboard_data.json). Models released in the last 90 days are outlined and labeled.

Avg. (5 domains) vs. parameters
Analysis

Metrics vs. Model Release Date

Each point is a model with a valid release date in the leaderboard. The y-axis is the average across the five FreshStack domains for α@10 (alpha-nDCG@10), C@20 (Coverage@20), and R@50 (Recall@50). Marker colors group model families (the family field in leaderboard_data.json). Models released in the last 90 days are outlined and labeled.

Avg. (5 domains) vs. release date
NeurIPS 2025 · Datasets & Benchmarks Track

Poster

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Cite us

BibTeX

@inproceedings{thakur2025freshstack,
  title={FreshStack: Building Realistic Benchmarks for Evaluating Retrieval on Technical Documents},
  author={Nandan Thakur and Jimmy Lin and Sam Havens and Michael Carbin and Omar Khattab and Andrew Drozdov},
  booktitle={The Thirty-ninth Annual Conference on Neural Information Processing Systems Datasets and Benchmarks Track},
  year={2025},
  url={https://openreview.net/forum?id=54TTgXlS2U}
}