Çağatay Çallı

Senior ML/AI Engineer · LLMs · Search · Recommendation Systems

A few things about me

Started in R&D and text mining - semantic search, NLP, a thesis on Explicit Semantic Analysis and search result clustering, and Google Summer of Code at the Eclipse Foundation.
Co-founded a social media analytics startup.
Helped scale Udemy, focusing on search, recommendations and ML infrastructure.
Built cloud data platforms and Spark pipelines at bp across globally distributed teams.
Shipped the DuckDuckGo Android app early on.
Now independent, I help teams design and ship LLM, search and recommender projects end-to-end.

LLM-based information extraction, especially on messy real-world text.

Search and ranking systems for marketplaces and content platforms.

Recommender systems and cross-sell features close to the product.

Data platforms and pipelines on modern stacks (Spark, Hive, AWS).

ML plumbing: evaluation, deployment, and the boring bits that keep models running.

Most ML problems are product and data problems in disguise.
Simple, well-instrumented models in production beat fancy models stuck in notebooks.
Owning the full loop (data → model → serving → eval) matters more than owning a narrow slice.
Clear metrics and honest evaluation save more time than any clever architecture.

"EasyESA: A Low-effort Infrastructure for Explicit Semantic Analysis" - ISWC 2014

Wikiprep-ESA - Open-source Explicit Semantic Analysis (Python, Lucene)

Ekşin - Android client for Ekşi Sözlük, Turkey's largest social dictionary (30K+ users)

Google Summer of Code 2007 - The Eclipse Foundation (Eclipse Platform & ECF)

M.Sc. Computer Engineering - Middle East Technical University 2010

Thesis: "Improving search result clustering by integrating semantic information from Wikipedia"

B.Sc. Computer Engineering - Middle East Technical University 2007