Python & SQL Tutorials
In-depth tutorials written by Ameer Abdullah, Data Science & AI/ML graduate. Each article explains not just what the code does, but why, building the mental model you need for technical interviews.
Python Tutorials
12 articlesHow to Crack Tech Interviews with Trace Tables
A step-by-step method for predicting Python output under pressure without running code.
6 min5 Essential Python String Slicing Tricks
Negative indices, step sizes, and reversals: master the patterns that show up in trace questions.
5 minWhy Dry-Running Beats LeetCode Rote Memory
Pattern decks fail when interviewers change types, side effects, or control flow.
5 minReading Python List Comprehensions Line by Line
Desugar comprehensions into nested loops before you predict output.
6 minMutable Default Arguments: Classic Python Trap
Why def f(lst=[]) causes shared state, and how to spot it in a trace.
5 minExplaining Your Thinking in Phone Screens
Structure your narration so interviewers can follow your trace table aloud.
6 minRecursion Trace Tables: Step-by-Step Guide
Stack frames make recursion traceable once you tabulate calls and returns.
6 minPython Dictionary Iteration Order and Pitfalls
Insertion order, views, and runtime mutations in common dry-run themes.
5 minAdvanced Recursion Trace Tables Guide
A deep-dive into tracing recursive functions with tips for stack visualization, memoization, and common interview pitfalls.
8 minPython Object Aliasing & Shared State
Concrete strategies to detect when variables share objects, how to represent aliases in trace tables, and production fixes for accidental shared state.
7 minTop 10 Trace Table Interview Questions
Ten compact, high-value trace questions with step-by-step answers you can practice in ten minutes a day.
9 minLearn Effective Python Coding Techniques 2026
Modern Python 3.12+ features, pattern matching, walrus operator expressions, and memory-safe design patterns.
8 min
SQL Tutorials
6 articlesSQL Joins Explained for Tech Interviews
Inner, left, right, and full outer joins: understand what rows survive and why before your next data round.
6 minSQL Window Functions: RANK, ROW_NUMBER & LEAD
Aggregate without collapsing rows: the core skill data engineers and analysts get tested on.
7 minCTEs vs Subqueries: Performance & Usage
Common Table Expressions improve readability but the performance story is more nuanced than most articles admit.
6 minGROUP BY vs HAVING: Core SQL Traps
Understanding what each clause filters and when to use WHERE versus HAVING prevents the most common SQL mistakes.
6 minSQL Indexes in Interviews: Essential Guide
B-tree indexes, composite index column order, and when a full table scan is actually faster.
7 minLearn SQL Query Optimization Tips & Tricks
Window function partitioning, recursive CTEs, optimizing LEFT JOIN vs EXISTS, and eliminating non-SARGable bottlenecks.
8 min
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