Namusoboko Nelson

AI Engineer in 365 days
🔥 Day 13/365
Weekly demos

[Namusoboko Nelson @namusoboko]

"cleaning" is two jobs wearing the same name.
one must run before chunking.
one must never touch the chunks.
found the flaw by asking one question.
that was today's lesson

[Namusoboko Nelson @namusoboko]

wanting to learn something doesn't mean learning it the right way.

you can't tell if you're on the right track.

figured out how to learn and build better.

that was today's lesson

[Namusoboko Nelson @namusoboko]

Day 11/365

[Namusoboko Nelson @namusoboko]

Today's biggest lesson wasn't a concept, it was strategy.

Built my RAG across too many layers at once. When things broke, I couldn't tell where issues came from.

New rule: one layer at a time. Prove each good before moving up.

A solid lower layer makes debugging upper trivial

[Namusoboko Nelson @namusoboko]

Day 10/365

Today, i have sub-split large chunks
Only one was able to produce a correct answer/3

The culprit remains the scoring(BM25) as it rewards keyword

Next: Working on the scoring

#RAG #LearnInPublic #LLMs #AIEngineering

[Namusoboko Nelson @namusoboko]

Day 9/365

Splitter orphaned titles: 35-char chunks alone.

Glued tiny chunks onto next: 35→18 named.

Retrieval? Unchanged. Code merely mentioning 'fixed-size' beat the section about it.

BM25 loves density, not meaning. Scoring next.

#RAG #LearnInPublic #LLMs #AIEngineering

[Namusoboko Nelson @namusoboko]

Day 8/365 🔥

lesson: naive structural chunking, BM25 bias.

Split by dividers -> 35 chunks; TOC beat the definition. A smaller chunk beat the big one with the answer
BM25 rewards short chunks.

Next: attach headers, cap sections.

#RAG #LearnInPublic #LLMs #AIEngineering

[Namusoboko Nelson @namusoboko]

repo https://t.co/VaLAnzWszk

[Namusoboko Nelson @namusoboko]

Day 7/365 🔥

lesson: 3 failure modes, 1 root cause.

max_tokens=300 → thinking ate the budget before the answer.

DeepSeek hides its thinking, so we got nothing. Nemotron shows it, so we got thoughts only.

Fix: 2500 → 9/9 both models.

#RAG #LearnInPublic #LLMs #AIEngineering

[Namusoboko Nelson @namusoboko]

Day 6/365 🔥

lesson: one stopword kept hijacking my BM25.

"what" appears in only 2 of 75 chunks → huge weight → a section beat the real answer.

Fix: strip stopwords first.

Result: hijack dead. chunk-500 answered for the first time

#RAG #buildinpublic #LLMs #AIEngineering

[Namusoboko Nelson @namusoboko]

Day 5/365 🔥

[Namusoboko Nelson @namusoboko]

RAG lesson: my first retriever counted DISTINCT question words per chunk.

That meant: ① filler words weighed same as content words ② 7 mentions = 1 point ③ bigger chunks got free chances ④ constant ties, first-wins. Replaced it with BM25.

#RAG #buildinpublic #LLMs #AIDev

[Namusoboko Nelson @namusoboko]

Day 4/365🔥 building RAG from scratch:
• "chunking?" ≠ "chunking" — one strip() fixed it.
• Zero matches ≠ chunk #0. Return empty + score 0.
• Free tiers: great to start, sweeps need reruns.

#BuildInPublic #AIEngineering #RAG #LLM

[Namusoboko Nelson @namusoboko]

Day 3/365 🔥

[Namusoboko Nelson @namusoboko]

My RAG failed — I added receipts: chunk, score, matches. 3 questions, 3 token-level bugs: tokenization mismatch (chunking?≠chunking, fixed-size=1 token), stop-word noise ({the:5, are:1, of:1}). Make failures visible first.

#BuildInPublic #RAG

[Namusoboko Nelson @namusoboko]

1/3 questions answered today. 33% retrieval success rate. 😅

Asked my own document:
✅ "whats fixed size chunking?" → answered cleanly
❌ "whats chunking?" → got the title page
❌ "what are the drawbacks?" → "context does not mention it"

code: https://t.co/VaLAnzWszk

[Namusoboko Nelson @namusoboko]

Day 2/365

Two lessons today

1. Chunking:
Fixed-size Splitting is simple but cuts words in half
Used overlap to preserve context

2. Keyword search:
Substring matches cause false positives
Need exact word matching

#BuildInPublic #RAG #AIEngineering

[Namusoboko Nelson @namusoboko]

@nanimono_toyama Thanks for the support. Appreciate you rooting for the 365. Showing up is day 1, now it��s time to just keep executing. Let’s crush it. 🔥

[Namusoboko Nelson @namusoboko]

Officially starting my AI engineering journey today. Posting so I can't lie to myself about whether I actually showed up.

Day 1/365🔥

#BuildInPublic #AIEngineering

[Namusoboko Nelson @namusoboko]

@pyconuganda The Pycon website is currently down unless it's only me facing this.