Replacing an existing Swift iOS app with a cross-platform rewrite (same bundle id): will App Store update work and will user data persist?

Summary This postmortem analyzes what happens when a native Swift iOS app is replaced with a cross‑platform rewrite (React Native) while keeping the same bundle identifier and shipping it as a standard App Store update. The focus is on data persistence, Keychain continuity, and App Store acceptance. The short answer: yes, this works, but only … Read more

Bottom border not visible on 100vh element

Summary A full‑height (100vh) container can unexpectedly hide its bottom border because the browser’s viewport height does not always equal the visible layout height. Mobile UI chrome, scrollbars, and fractional pixel rounding often push the bottom edge just outside the rendered area. Even with box-sizing: border-box, the border can fall below the fold. Root Cause … Read more

MongoDb Connection failed : Error: querySrv ECONNREFUSED

Summary The MongoDB connection failure with Error: querySrv ECONNREFUSED occurred due to network connectivity issues between the Node.js application and MongoDB Atlas. The root cause was a misconfiguration in MongoDB Atlas network access settings, preventing the application from establishing a connection. Root Cause Network Access Misconfiguration: MongoDB Atlas had 0.0.0.0/0 as the allowed IP address, … Read more

Gitlab Registry Error pulling Image within Cluster

Summary A deployment inside a MicroK8s cluster failed to pull images from an internal GitLab Registry (registry.learning.com) even though pushing from GitLab Runner and pulling from external machines worked. The failure occurred only inside the cluster, specifically when ArgoCD attempted to deploy workloads. The core issue was internal DNS resolution inside the cluster failing to … Read more

Function SUM in SQL

Summary When SUM() is applied to a varchar column, SQL Server attempts an implicit conversion to a numeric type. If the conversion succeeds, SQL performs a normal numeric sum; if it fails, SQL throws a conversion error. The surprising part is that many varchar values look numeric, so SQL silently converts them and returns a … Read more

Winform loading WebUrl not determine whether is Browser or WinForm

Summary The issue arises when attempting to determine whether an ASP.NET WebForm URL is loaded in a WinForm App or a Browser. The provided EnvironmentHelper class fails to correctly identify the WinForm environment, leading to incorrect detection. Root Cause The root cause is the mismatch in execution contexts between ASP.NET WebForms and WinForms. The System.Web.HttpContext.Current … Read more

Twilio inbound call routing using webhooks — returning agent phone number via TwiML (backend-only MVP)

Summary Twilio inbound call routing via webhooks in a backend-only MVP using FastAPI + PostgreSQL encountered a critical issue: inconsistent call routing due to missing agent availability checks. This led to dropped calls and poor customer experience. Root Cause Missing agent availability check: The system routed calls to agents without verifying their availability, leading to … Read more

How to “pass-through” an async function?

Summary When wrapping an async function in .NET, the key decision is whether to return the Task directly or await it. Returning the Task preserves the async nature, while awaiting it resolves the result immediately. The correct approach depends on whether you want to pass-through the async operation or control its execution. Root Cause The … Read more

Managing user roles & permissions on multiple applications

Summary This incident analyzes a multi‑application user‑management architecture where authentication is centralized, but authorization (roles & permissions) is unclear and inconsistently implemented. The lack of a clear ownership model for authorization caused confusion, duplicated logic, and operational delays when onboarding users. Root Cause The core issue was mixing authentication concerns with authorization concerns across multiple … Read more

Dealing with Cumulative Phonetic Alignment Drift in CTC-based Quranic Recitation Correction System

Summary Cumulative Phonetic Alignment Drift in a CTC-based Quranic recitation correction system causes phantom errors and accuracy drops in long Ayahs (>20 words). The issue arises from imperfect word boundaries in CTC models and the complexities of connected speech (Wasl) in Quranic recitation. Root Cause CTC Model Limitations: Lack of precise word boundaries leads to … Read more