Nikolai Sachok

AI engineer & technical lead — production LLM systems: RAG, evals, agents. Founder/CEO background, now building hands-on.

[Nikolai Sachok @nsachok]

4/ For SQL, I use vetted templates, a column whitelist and read-only access. The model is not allowed to generate arbitrary SQL. Keep retrieval and aggregation separate: https://t.co/56FfQAqn8L

[Nikolai Sachok @nsachok]

1/ A vector search cannot count. If you ask how many suppliers are in the data corpus, it returns the k chunks most relevant to the question. Not a complete set or a reliable count.

[Nikolai Sachok @nsachok]

3/ I split the paths. Semantic questions go to the vector index. Questions such as "how many", "list all", "sum" etc. go to a small SQL metadata sidecar built during ingest. And a router selects the path.

[Nikolai Sachok @nsachok]

RRF is a small mechanism, but it removes one fragile parameter from hybrid retrieval. I use it in the open-source Strata-RAG project: https://t.co/56FfQAqn8L

[Nikolai Sachok @nsachok]

In retrieval-augmented generation, cosine similarity for vector search and full-text BM25 search scores should not be added together. They are complementary, but their raw scores live on different scales.

[Nikolai Sachok @nsachok]

Reciprocal Rank Fusion avoids raw scores. It sums 1/(k+rank) across both result lists. Items ranked high by both rise. So an unusual score range for one retriever cannot dominate.

[Nikolai Sachok @nsachok]

The first time I blended two retrievers, hand-weighting the scores was the obvious first idea. A weighted sum can look ok on one dataset, then drift when the corpus changes.

[Nikolai Sachok @nsachok]

Hey @toptal, looks like there is an issue on video submission during application process. Clicking on 'Complete submission' after successful uploading or recording gives an error

[Nikolai Sachok @nsachok]

@AppsFlyer Hi, your registration form submit button is not working on the password step. Unable to create an account.

[Nikolai Sachok @nsachok]

How app piracy can wreck your app business – and how you can fight back
https://t.co/vuXRFwFtXV

[Nikolai Sachok @nsachok]

@Bitbucket Pushes return HTTP 413 'Request entity is too large' for 2 days. Pushing 128M. Had no issues before regardless of the push size.

[Nikolai Sachok @nsachok]

@OnlinerBY А как зовут девушку, что выступила в образе Safari?

[Nikolai Sachok @nsachok]

Полезные советы для стартаперов и не только http://t.co/JhPA7Zb6j1

[Nikolai Sachok @nsachok]

@sergeiklimov Пишут, что у него одежда была бензином пропитана, как и у других метателей коктейлей, поэтому раздели: http://t.co/hDGWBTmfwC

[Nikolai Sachok @nsachok]

Отличный пост про то, почему на письма иногда не отвечают и что с эти делать. http://t.co/sjfY77Oxcg

[Nikolai Sachok @nsachok]

"App Store Optimization 201: Keyword Volume & Competition" http://t.co/YfC5ELQkdW

[Nikolai Sachok @nsachok]

@sergeiklimov Хотя, в начале августа может не получиться, лучше бы во второй половине. В любом случае буду рекомендовать знакомым.

[Nikolai Sachok @nsachok]

@sergeiklimov Да, непременно.

[Nikolai Sachok @nsachok]

Отличная статья о монетизации игроков в f2p.

The monetization secrets of Candy Crush Saga and Puzzle and Dragons http://t.co/rCAEEhljLF