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Showing posts with the label Python

Data Engineering Interview Preparation #2: DuckDB SQL, Data Quality and Parquet

Summary : Practice SQL for data engineering with DuckDB and a small network-traffic dataset. This hands-on example covers table creation, filtering, joins, aggregations, window functions, Pandas and SQL result checks, data-quality rules, and a Parquet round trip. SQL is a core tool for data engineers. It helps us explore source data, transform records, build analytical datasets, and check whether pipeline outputs are correct. You do not need to set up a separate database server to practice these patterns. With DuckDB, you can run analytical SQL directly from Python in a Kaggle notebook. In this exercise, we use a small CSV containing network events. Each row includes a timestamp, source IP, destination IP, port, protocol, bytes sent, and event duration. The goal is not just to write queries, but to follow a simple engineering workflow: ingest the data, inspect it, transform it, validate it, and save a verified output. Run the hands-on notebook: Data Engineering Interview Prepara...

Data Engineering Interview Preparation #1: Python, Pandas, SQL and DuckDB

Summary : Start your Data Engineering interview preparation with a practical Kaggle notebook covering Python, Pandas, SQL, DuckDB, data validation and Python/SQL result verification. If you are preparing for a Data Engineering interview, knowing Python and SQL syntax is only the beginning. You also need to understand how data moves through a workflow, how transformations are validated, and how to explain your technical decisions clearly. That is the purpose of Data Engineering Interview Preparation #1 , the first practical asset in my progressive Data Engineering interview-preparation series. This notebook is designed to give learners a low-friction starting point. It uses the Kaggle notebook environment and a small Sales Transactions dataset to connect Python, Pandas and SQL through practical examples. What You Will Learn In this first notebook , you will practice: Python variables and basic data types Lists, indexing, slicing and mutation Dictionaries and nested dicti...

How I Built an Autonomous Agentic AI Software Engineering Platform That Generates Code, Tests, Documentation, and Reviews Automatically

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Summary : Traditional AI coding assistants help developers write code faster, but they rarely automate the complete Software Development Life Cycle (SDLC). This post explains how I designed and implemented an autonomous Agentic AI Software Engineering Platform that converts plain-text feature requests into enterprise-grade Java applications, frontend code, automated tests, documentation, and compliance reports using a deterministic multi-agent architecture powered by Agentic frameworks, Python and LLMs. Introduction: Moving Beyond AI Code Completion AI-assisted programming has evolved rapidly over the past few years. Tools like GitHub Copilot and conversational AI assistants have significantly improved developer productivity by generating snippets, explaining code, and suggesting fixes. However, software engineering is much more than writing code. A complete feature requires architecture design, backend development, frontend implementation, automated testing, documentation, val...

Beyond plt.plot(): Matplotlib Concepts That Will Transform Your Visualizations

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Summary : Ordinary Python developers use Matplotlib only at a surface level. This article reveals five core Matplotlib concepts that explain how plots really work and how to gain control over customization, performance, and reliability. Introduction: Matplotlib Is More Than Just plt.plot() For many Python users, Matplotlib is one of the very first data visualization libraries they come across. It often gets learned by copying code snippets from tutorials or Stack Overflow and tweaking them until the plot looks right. First, view my Matplotlib tutorial below. Then, read on. While this approach works for simple charts, it treats Matplotlib like a black box. You run commands, a plot appears, and you move on. What gets missed is the carefully designed architecture underneath that gives Matplotlib its flexibility and power. Understanding that architecture is what separates a casual script writer from someone extraordinary, who can build complex, reliable, and reusable vis...

Pandas Is Changing: Powerful Upgrades Data Science Professionals Should Know About

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Summary : Pandas has evolved significantly in recent versions, bringing major improvements in performance, safety, and usability. This blog post highlights important upgrades that can help you write faster, cleaner, and more reliable data analysis code. Introduction: Pandas Is Evolving Fast For more than a decade, Pandas has been the go-to library for data manipulation in Python. Most of us have built strong habits around DataFrames, along with workarounds for a few long-standing quirks. If you are new to Pandas, view the Pandas Tutorial video below. Learn Pandas using the Pandas Playbook (datasets and Python code designed for data analysts and ML engineers, from Beginner to Intermediate, to master essential Pandas operations). What many developers do not realize is that some of those old frustrations are now being actively removed. With version 2.0 and beyond, Pandas has introduced deeper architectural improvements that change how it handles memory, performance, a...

Confusion Matrix in Machine Learning

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In this post, I explain Confusion Matrix in detail. Learn Confusion Matrix Definition and Intuition, Claim Approval Example, Confusion Matrix Table Layout, Core Concepts Explained (TP, TN, FP, FN), Confusion Matrix Formulae, Derived Metrics from the Confusion Matrix (Precision, Recall, F1, Specificity), and Visualization and Code. If you want to additionally learn about the following confusion matrix topics or comment, you can do so on my original Confusion Matrix article on LinkedIn here . Thresholding, ROC and PR Curves, Imbalanced Data and the Accuracy Paradox, Multiclass and Multi-Label Confusion Matrices (Visualization and Interpretation), Cost-Sensitive Decisions: Cost Matrix, Business Tradeoffs, and Setting Operational Thresholds, Calibration, Confidence, and When to Trust Model Probabilities, Practical Tips and Troubleshooting (Data leakage, label noise, sampling effects) — confusion matrix tutorial, debugging checklist for AI Developers and AI QA Testers, Ethics, Fairness an...

Introduction to LLMs in Python - Interview Questions and Answers

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In this post, I explain LLMs in Python, Python Setup & Installation, Inference with Transformers, Calling ChatGPT API in Python, Python Local Deployment with Hugging Face Models, Prompt Engineering in Python and FineTuning & Custom Training (including LoRA). You can test your knowledge of LLMs in Python by attempting the Quiz after every set of Questions and Answers. If you want my complete Introduction to LLMs in Python document that additionally includes the following important topics, you can message me on LinkedIn : Python Advanced Techniques (Streaming, Batching & Callbacks), Python Efficiency & #Optimization (quantization, distillation, and parameter‑efficient tuning), Integration & Deployment Workflows, LLMs in Python Best Practices & Troubleshooting, and consolidated Introduction to LLMs in Python Quiz (with answer explanations to reinforce learning). Question : What do I mean by "Introduction to LLMs in Python"? Answer : Introduction to LL...