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Data science/ML/AI
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Data science and machine learning hub Python, SQL, stats, ML, deep learning, projects, PDFs, roadmaps and AI resources. For beginners, data scientists and ML engineers 👉 https://rebrand.ly/bigdatachannels DMCA: @disclosure_bds Contact: @mldatascientist
Show more📈 Analytical overview of Telegram channel Data science/ML/AI
Channel Data science/ML/AI (@datascience_bds) in the English language segment is an active participant. Currently, the community unites 13 674 subscribers, ranking 9 377 in the Technologies & Applications category and 31 635 in the India region.
📊 Audience metrics and dynamics
Since its creation on невідомо, the project has demonstrated rapid growth, gathering an audience of 13 674 subscribers.
According to the latest data from 09 June, 2026, the channel demonstrates stable activity. Although there has been a change in the number of participants by 155 over the last 30 days and by 5 over the last 24 hours, overall reach remains high.
- Verification status: Not verified
- Engagement rate (ER): The average audience engagement rate is 8.03%. Within the first 24 hours after publication, content typically collects 2.25% reactions from the total number of subscribers.
- Post reach: On average, each post receives 1 098 views. Within the first day, a publication typically gains 308 views.
- Reactions and interaction: The audience actively supports content: the average number of reactions per post is 5.
- Thematic interests: Content is focused on key topics such as panda, learning, row, api, ethic.
📝 Description and content policy
The author describes the resource as a platform for expressing subjective opinions:
“Data science and machine learning hub
Python, SQL, stats, ML, deep learning, projects, PDFs, roadmaps and AI resources.
For beginners, data scientists and ML engineers
👉 https://rebrand.ly/bigdatachannels
DMCA: @disclosure_bds
Contact: @mldatasci...”
Thanks to the high frequency of updates (latest data received on 10 June, 2026), the channel maintains relevance and a high level of publication reach. Analytics show that the audience actively interacts with content, making it an important point of influence in the Technologies & Applications category.
13 674
Subscribers
+524 hours
+197 days
+15530 days
Posts Archive
13 674
⚡️Data Lake
A data lake is a centralized storage system that keeps raw data in its original format.
Think of it like a giant digital reservoir where you dump data first and decide what to do with it later.
The core idea is: Store now. Structure when needed.
Where it is used:
➖Big data platforms
➖Machine learning pipelines
➖Analytics systems
➖Event and log storage
➖IoT data ingestion
It's purpose is to store massive volumes of structured, semi structured, and unstructured data cheaply and flexibly.
How it works (simple flow):
1. Data comes from many sources
2. Stored in raw form in the lake
3. Processed or transformed when needed
4. Consumed by analysts, ML models, or dashboards
⚠️Things you must know:
👉 It's not the same as a data warehouse
👉Schema is applied on read, not on write
👉 Very scalable and low cost
👉Can become a "data swamp" without governance
👉 Works best with strong metadata management
✅Mental model:
Data warehouse = bottled water (clean and ready)
Data lake = natural lake (raw but powerful)
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🔁 K-Fold Cross Validation
K-Fold exists to answer one honest question:
Will this model work on unseen data?A single train/test split is unreliable, especially with small datasets. So K-Fold simulates multiple “future tests” using the same data. 🧠 What It Really Does Instead of one split, we: 🔀 Divide data into K folds 🔁 Train the model K times 📦 Each time: one fold validates, the rest train 📊 Average the scores Every sample gets validated once, which reduces evaluation noise and gives a more trustworthy estimate. Important: It improves evaluation, not the model itself. ⚠️ What People Often Miss 🚫 Do NOT use K-Fold as your final test. Keep a separate test set ⚖️ Use Stratified K-Fold for imbalanced classification. ⏳ Do NOT use standard K-Fold for time series. 📊 K = 5 or 10 is usually enough. ✅ In short K-Fold is just: A smart way to reuse limited data to simulate multiple real-world tests. No magic. Just careful evaluation.
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Data Science Interview Questions and Answers.pdf13.55 MB
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VC Dimension
In theory courses, VC dimension appears abstract.
But it answers a deep question:
How complex is your model’s decision boundary?VC dimension measures the largest number of points a model can shatter (perfectly classify in all labelings). Why this is important❔ Two models with similar parameter counts can have very different capacities. For example: 📦 k-NN → very high effective capacity 📐 Linear classifier → limited capacity 🌳 Deep trees → extremely high capacity What you need to understand Generalization depends on capacity relative to data size. Too much capacity with little data leads to overfitting. ✅ VC dimension is about expressive power, not just number of parameters.
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Repost from Programming Quiz Channel
Which ML concept refers to splitting data into training and testing subsets?
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LLMs are getting insanely popular lately and suddenly everyone is talking about AI, chatbots, copilots, agents… so let’s clear it up 👇
So what are LLMs really? 🤔
LLMs = Large Language Models
Think of them as insanely smart text prediction machines that learned from tons of books, code, docs, and conversations 📚💻
Why everyone is obsessed right now 🔥
• They can write code 🧑💻
• Explain complex stuff like a friend 🗣
• Analyze data 📊
• Power chatbots, copilots, agents 🤖
• One model, MANY tasks
Why they exploded now 🚀
• GPUs got better and cheaper
• Open source models became really good
• Companies realized: this saves time and money 💰
The most famous LLMs you hear about 👀
• GPT-4 / GPT-4.1 by OpenAI
• Claude 3 by Anthropic
• Gemini by Google
• LLaMA 3 by Meta
• Mistral by Mistral AI
Where LLMs are actually used today 🛠
• Chatbots and AI assistants
• Writing SQL and Python
• Data analysis and reporting
• Customer support automation
• Internal company tools
Important truth 💡
LLMs are not magic 🪄
They are very powerful autocomplete with reasoning skills.
Learn how to use them properly and you are already ahead of most people 😉
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🧠 LayerNorm vs BatchNorm: Same Goal, Different Behavior
Both techniques normalize activations, but they operate differently.
Batch Normalization
📦 Normalizes across the batch
⚡️ Depends on batch statistics
🖼 Works very well in CNNs
⚠️ Sensitive to small batch sizes
Layer Normalization
🔬 Normalizes across features per sample
📏 Independent of batch size
🤖 Preferred in transformers and NLP
✅ Stable for sequence models
Why transformers use LayerNorm❔
Sequence models often run with variable or small batches.
LayerNorm avoids reliance on batch statistics and stays stable.
✅ Rule of thumb
🖼 CNNs → BatchNorm
🤖 Transformers → LayerNorm
📌 They look similar mathematically but normalize along different axes.
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⚡️📊 One Line Feature Scaling
Scaling features without touching sklearn 👀
df["age_scaled"] = (df["age"] - df["age"].mean()) / df["age"].std()13 674
Python for Data Analytics: The Ultimate Library Ecosystem (2026 Edition)
This wheel is the Python data stack that's recommended from raw scraping to production insights:
➡️ Data Manipulation → Pandas, Polars (the fast successor), NumPy
➡️ Visualization → Matplotlib, Seaborn, Plotly (interactive dashboards)
➡️ Analysis → SciPy, Statsmodels, Pingouin
➡️ Time Series → Darts, Kats, Tsfresh, sktime
➡️ NLP → NLTK, spaCy, TextBlob, transformers (BERT & friends)
➡️ Web Scraping → BeautifulSoup, Scrapy, Selenium
🔥 Pro tip from real projects:
👉Switch to Polars when Pandas starts choking on >1 GB datasets
👉 Use Plotly + Dash when stakeholders want interactive reports
👉 Combine Darts + Tsfresh for serious time-series feature engineering
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🤯📈 Detect Outliers in 5 Lines
Simple Z score based outlier detection.
import numpy as np
z = (df["salary"] - df["salary"].mean()) / df["salary"].std()
outliers = df[np.abs(z) > 3]13 674
Pre-Chunking vs. Post-Chunking (On-Demand Chunking)
This visual breaks down two common ways to chunk documents in Retrieval-Augmented Generation (RAG) systems,and when each makes sense.
Pre-Chunking
Documents are cleaned, split into chunks, embedded, and stored ahead of time.
• Pros: Fast retrieval at query time, simpler runtime pipeline.
• Cons: Rigid,changing chunk size or strategy means reprocessing the entire dataset.
• Best for: Stable datasets, high-throughput apps, predictable queries.
Post-Chunking / On-Demand Chunking
Documents are stored whole; chunking happens after retrieval based on the user’s query.
• Pros: More flexible and query-aware, often more relevant context.
• Cons: Higher latency and infrastructure complexity.
• Best for: Evolving content, exploratory queries, precision-focused use cases.
🔑 Takeaway:
There’s no one-size-fits-all. If speed and scale matter most, pre-chunk. If adaptability and relevance are key, post-chunk. Many production systems even combine both.
