Production Bugs

Spring Boot JWT cookies not sent cross-site from React frontend on Vercel -> Render backend (403 Forbidden)

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Summary A production outage occurred where a React frontend on Vercel could not authenticate against a Spring Boot backend on Render, resulting in 403 Forbidden errors. The root cause was misconfigured SameSite cookie attributes and missing CSRF protection. While SameSite=None was intended, it requires the Secure attribute and explicitly requires SameSite=None (case-sensitive). More critically, disabling … Read more

How to make a file server with vanilla Node.js without any database library

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Summary To create a file server with vanilla Node.js without any database library, we need to focus on file system management and user authentication using local JSON files. This approach allows for a simple, database-less solution for storing and retrieving user files. Root Cause The root cause of complexity in implementing such a system lies … Read more

Can’t change sprite position in AnimationPlayer Godot

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Summary In Godot 3.x/4.x, the Sprite2D/3D position property is not directly keyable in AnimationPlayer. Attempting to animate position on a Sprite node directly causes conflicts (e.g., snapping back to the initial key or being ignored). To animate a sprite’s transform, you must animate a parent Node2D (or Node3D) and keep the Sprite as a child … Read more

Refactor Stateful/Loop-based approach into Set-based approach

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Summary The provided Oracle Pipeline function attempts to calculate marketing budget allocation using a stateful, row-by-row procedural approach within a database cursor loop. While functionally valid for sequential datasets, this implementation is architecturally fragile and inefficient for large-scale data processing. The function relies heavily on mutable variables (v_grp_alloc_cum, v_total_budget, v_grp_max_alloc) to track state across rows, … Read more

How to become a Python backend developer and start thinking like an engineer, not just a coder?

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Summary A junior developer asked how to transition from writing Python scripts to becoming a backend engineer who thinks like a systems engineer. This postmortem-style guide outlines the mindset shift required to move beyond “making it work” to building systems that survive production. The core insight is that engineering is defined by trade-off analysis, failure … Read more

Refreshing new access token using reacjs

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Summary The challenge is implementing a transparent token refresh mechanism in React that automatically handles expired access tokens without interrupting the user experience. The issue stems from managing asynchronous token state across concurrent API requests while preventing race conditions when multiple requests discover an expired token simultaneously. The solution requires a centralized HTTP client with … Read more

Salesforce Apex trigger fires twice on a single record update

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Summary The Salesforce Apex trigger is firing twice on a single record update, causing unexpected behavior. This issue arises from the trigger updating the record, which in turn triggers the same trigger again, resulting in infinite recursion. To prevent this, it’s essential to understand the trigger context and implement measures to avoid recursive trigger executions. … Read more

Bigquery How do I get big Query to take column release_date as column only and not to insert date function in it

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Summary A user reported that BigQuery automatically treats a column named release_date (or similar) as a DATE type during query execution, even when the intent is to treat it as a raw string or identifier. This occurs because BigQuery’s query parser performs automatic type inference based on column names and schema metadata, wrapping the value … Read more

How to maximize satisfied customers when owner is grumpy? (Sliding Window Java solution)

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Summary The provided Java solution attempts to solve the “Maximize Satisfied Customers” problem using a sliding window technique. The problem asks to maximize customer satisfaction by choosing a contiguous period of minutes during which the owner stops being grumpy. The solution correctly identifies the base satisfaction (customers happy when the owner is naturally not grumpy) … Read more