2006 — 2011
Tallinn, Estonia
59°26′ N · 24°45′ E
SergeiMaslennikov
Hi, I'm Sergei. Navigator by degree, sports-data nerd by habit, AI builder by choice.
Grew up by the sea in Pärnu
Log 02 · Digital twin
Don't feel like reading all this? Ask my digital twin anything, it's more talkative than me.
It knows my background, projects and opinions, and speaks English, Estonian and Russian. If it gets stuck, it pings my phone and I can jump into the chat myself.
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Log 03 · About
I used to navigate ships. Then I spent ten years reading tennis matches like spreadsheets. These days I try to make LLMs do useful things and read the Stoics when the code won't cooperate.
I trust data more than my gut, mostly because sports data showed me how often my gut is wrong. I also think time and attention are the only things you can't buy back, so I like handing boring work to machines. That's how I ended up building with LLMs.
Log 04
The route so far
2013 — 2014
Deck Officer
Watchkeeping on container ships.
2015 — 2024
Independent Quantitative Analyst — Sports Markets
Ten years of reading tennis and volleyball matches like spreadsheets.
End of 2024
A break
I decided to take a break and reconsider my views on life, because I no longer saw meaning or value in what I was doing.
2025 — 2026
Back to learning
Show the 7 courses ↓Hide the courses ↑
May — Oct 2025
Google Data Analytics Professional CertificateCoursera · certification
Jun 2025
Practical Python Course: from Basics to AdvancedWexler.io · Egor Wexler
Oct 2025 — Feb 2026
AI Engineer Core Track: LLM Engineering, RAG, QLoRA, AgentsUdemy · Ed Donner
Nov 2025
Python Data Science: Data Prep & EDA with PythonUdemy · Alice Zhao, Maven Analytics
Dec 2025
Natural Language Processing in PythonUdemy · Alice Zhao, Maven Analytics
Dec 2025
Python Data Science: Unsupervised Machine LearningAlice Zhao, Maven Analytics
Mar 2026
AI Coder: Vibe Coder to Agentic EngineerUdemy · Ed Donner
Now
Building with AI
Log 05
Projects
Sep — Oct 2026
Avatar
A digital twin with a human in the loop: a chat where visitors talk to an AI version of me. It answers from my profile and FAQ, streams its replies, and sends a notification to my phone when a question needs me. From an admin dashboard I can join any conversation, which makes it a three-way chat between the visitor, the AI and me. Built with the OpenAI Agents SDK, a FastAPI backend, Supabase and a Vite/TypeScript frontend. It's deployed to Fly.io through GitHub Actions and embedded in my personal website.
Aug 2026
Autonomous Trading Floor
An equity trading simulation where four autonomous LLM agents manage virtual portfolios: researching the market, executing trades, and rewriting their own strategies based on how their past trades performed. Built on the Model Context Protocol and the OpenAI Agents SDK, with a FastAPI backend and a Vite/TypeScript dashboard.
Jun — Jul 2026
Tennis Match Research Dashboard
LLM agent engineering on a real domain. The dashboard renders four independent signals side by side for every upcoming ATP / WTA tour-level singles match — market consensus odds, a trained LightGBM probability, a surface-Elo baseline, an LLM-discovered news block — plus a deterministic “why model differs” panel whenever the model-vs-market gap exceeds 10pp. The purpose of the project is to demonstrate end-to-end ML + LLM engineering: data ingestion, feature engineering, model training, evaluation, LLM tool-calling integration, deployable interface.
Not a betting toolLog 06
Toolbox
$ cat toolbox.txt
python# use daily
claude-code# use daily
codex# built with
opencode# built with
openai-agents-sdk# built with
mcp# built with
crewai# built with
fastapi# built with
vite-typescript# built with
rag# built with
lightgbm# built with
qlora# tried
sql# tried
qdrant# tried
$
Log 07
Outside work
- Training
- 20 years, almost daily. Gym, HIIT, CrossFit.
- Diet
- Zero tolerance for alcohol, nothing sweet other than fruit.
- Time off
- Long walks in the forest, no phone.
- Interested in
- Fitness and sport, neurobiology, Stoicism.
- School
- Straight-A student. Not sure if that counts as a good thing.
- Film
- Interstellar, by Christopher Nolan.
- Sportsman
- Andy Murray.
- Role model
- Pavel Durov.