Creating chatbox with firebase

Summary This incident stemmed from a partially implemented message‑sending flow in a Firebase‑based chat application. The system entered an inconsistent UI/auth state because the sendMessage() logic was cut off mid‑implementation, causing runtime failures and preventing messages from being sent. Root Cause The root cause was incomplete control‑flow logic inside the sendMessage() function. The code ends … Read more

Why is my Flutter app generating high Firebase RTDB and Cloud Functions costs

Summary High Firebase costs in a Flutter bingo app stem from inefficient data structures, excessive Realtime Database (RTDB) operations, and frequent Cloud Functions triggers. Optimizing data models, reducing RTDB reads/writes, and minimizing function invocations are critical to cost reduction. Root Cause Inefficient data structure: Storing large, nested objects in RTDB leads to oversized payloads. Overuse … Read more

AliExpress Dropshipping API – Persistent “IncompleteSignature” Error on Token Exchange (Node.js/TypeScript)

Summary The AliExpress Dropshipping API integration in a NestJS application consistently failed with an IncompleteSignature error during token exchange. The issue stemmed from incorrect signature generation due to misinterpretation of the AliExpress signature algorithm and missing URL encoding for specific parameters. Root Cause Incorrect Signature Construction: The signature string included parameter keys and values without … Read more

How do i setup a database in ASP.net(MVC)

Summary Setting up a database in an ASP.NET MVC application involves configuring Entity Framework, installing necessary NuGet packages, and setting up a connection string. A recent issue occurred when a junior developer failed to properly configure the database context, leading to runtime errors and application crashes. Root Cause The root cause was: Missing NuGet packages … Read more

TBB interaction in python binding

Summary This incident involved a double‑free crash triggered when importing a Python module backed by a C++ library that embeds oneTBB, but only when NumPy is imported first. The failure was caused by two independent TBB runtimes being loaded into the same Python process, each attempting to manage and free overlapping internal resources. Root Cause … Read more

LangChain.js createHistoryAwareRetriever with Ollama embeddings throws invalid input type error

Summary A type mismatch inside LangChain.js caused createHistoryAwareRetriever to fail when paired with OllamaEmbeddings. The retriever expected a string input, but the history‑aware wrapper produced a message array, triggering an “invalid input type” error. Root Cause The failure stems from incompatible input/output expectations between: ChatOllama, which emits AIMessage / HumanMessage objects createHistoryAwareRetriever, which expects the … Read more

Jetty 12 API changes: How to replace HttpInput.Interceptor and HttpOutput.Interceptor

Summary This postmortem analyzes the Jetty 12 API removal of HttpInput.Interceptor and HttpOutput.Interceptor, why these hooks disappeared, what breaks during migration, and how senior engineers replace this functionality using Jetty 12’s new Handler/Filter pipeline and Content.Source / Content.Sink abstractions. Root Cause The failure occurs because Jetty 12 removed the legacy Servlet‑container–centric interception APIs (HttpInput.Interceptor, HttpOutput.Interceptor) … Read more

Excel SetFocus on Barcode Textbox -Not working

Summary The issue involves an Excel VBA userform where Textbox1 fails to regain focus and highlight the barcode after the first scan, especially when the same barcode is scanned consecutively. The AfterUpdate event in Textbox2 does not fire, preventing the focus from returning to Textbox1. Root Cause Event Handling Conflict: The AfterUpdate event in Textbox2 … Read more

I am trying to exclude a file that has -PK in its name in the code below. Auto print from email. File name always is a pdf and has -PK in its name

Summary An Outlook VBA script intended to auto-print email attachments failed to exclude files containing -PK in their names. The issue arose because the script lacked a filename validation check, causing all matching file types (e.g., .pdf) to be printed regardless of their name. Root Cause The script did not include logic to filter filenames … Read more