News for hackers. Stuff that matters.

amallia

More on latency and search:

We benchmark against 10 other search APIs on fresh news queries. The median was around 1.2s; we came in around 166ms and scored highest on answer accuracy (89% vs 84% for the next cluster).

Latency matters because agents loop. A 1.2s first call eats the budget for follow-ups — you get one shot at framing the query. At sub-250ms the agent can actually search, read, reformulate, and search again.

Measuring this stuff carefully is something I've been at for a while. My ECIR 2019 paper (linked below) was an exhaustive study of 11 index compression methods across 5 query processing algorithms on standard collections — the codebase became PISA, which a lot of IR folks still use for research. Almost ten years later, the workload has changed completely (agents, not humans), but the benchmarking discipline is the same.

ECIR 2019 paper: https://www.antoniomallia.it/uploads/ECIR19c.pdf

Pisa Engine: https://github.com/pisa-engine/pisa

Full methodology and charts for Seltz: https://seltz.ai/blog/why-we-built-seltz

Show HN: Seltz – The fastest, high quality, search API for AI agents

https://console.seltz.ai/login

Hi HN, Antonio here. Founder of Seltz.Seltz is a web search API built for AI agents. We wrote the crawler, the index, and the retrieval models ourselves, in Rust, by a team that's spent years building web search at scale. In our tests, queries come back in under 200ms.Efficiency was the first design principle. Search sits on the critical path: agents can't generate their first tokens or kick...

( Read More... | 1 comment | 5 points | on HN )
Re:Multi-vector retrieval as a fast second-stage reranker on Tuesday June 24, 2025 @02:48PM (#44369489)
Multi-vector retrieval as a fast second-stage reranker to improve ranking quality without hurting latency
Thanks sota_pop. I am looking for contributors to help me integrate new features. Please come and join me!

Show HN: Kentro – a fast Rust library for K-Means clustering

https://github.com/pisa-engine/kentro

Double-digit speed-ups over naïve K-Means Parallel by default (Rayon) Balanced & spherical variants in one crate Memory-savvy for multi-GB datasets Builder API that just feels ergonomicDocs are live, the license is Apache-2.0, and the repo is one `cargo add kentro` away. Give it a spin—curious to hear how it performs in your pipelines!

( Read More... | no comments | on HN )

Show HN: BMP – Fast, Exact Learned Sparse Retrieval for RAG

https://github.com/pisa-engine/BMP

We built BMP, a fast and memory-efficient search engine for learned sparse retrieval — written in Rust and with Python bindings.It supports exhaustive (non-approximate) search over large collections like MS MARCO, without dropping query terms or pruning the index.Features:- Full support for SPLADE, uniCOIL, CSV, and similar models- No static pruning – keeps full index fidelity- No term dropping...

( Read More... | no comments | on HN )
Re:Show HN: Pisa – Full Text Search Engine Written in C++ on Saturday March 14, 2020 @05:03PM (#22578673)
Maxime Caron?
Re:Show HN: Pisa – Performant Indexes and Search for Academia on Wednesday August 14, 2019 @06:49AM (#20694204)
Yes, you can index any content as long as it is parsable. You can easily plug a new PDF parser and start indexing your PDF articles...
Re:Show HN: Pisa – Performant Indexes and Search for Academia on Wednesday August 14, 2019 @06:47AM (#20694198)
We rely on different user intents. Search for "PISA engine" or "PISA search" and you will find this tool and not the city. Being found by the keyword `PISA` on Google is not necessarily our main goal. We are not selling anything, the community is just building a product for IR research. We are willing to gain interest from skilled people in the end. I don't think it really matters if there are `news` about the city, we are not targeting the news anyway.

Also, think about `Windows` or `Go`, there is no way you get confused once these words are in the right context.

Re:Show HN: Pisa – Performant Indexes and Search for Academia on Wednesday August 14, 2019 @06:30AM (#20694138)
Thanks for the feedback!
Re:Show HN: Pisa – Performant Indexes and Search for Academia on Wednesday August 14, 2019 @06:29AM (#20694133)
Good to see you Marko!
Interesting! As long as there is no other OS software with the name PISA it should not be too confusing. Thanks for pointing out.
Writing some documentation is definitely the first thing to get familiar with the code. Are you a C++ developer?
We are looking for contributors! Please reach out if you are interested in collaborating.
We are looking for contributors! Please reach out if you are interested in collaborating.

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