External USB Fingerprint scanner

Summary The goal of this article is to discuss the technical challenges of integrating an external USB fingerprint scanner with a React Native app (Expo) for both iOS and Android platforms. Key considerations include compatibility, security, and platform-specific limitations. Root Cause The root cause of the complexity in achieving this integration lies in the following … Read more

In vm2 how to make the global/sandbox object available in imported modules?

Summary The question revolves around making the global/sandbox object available in imported modules when using the vm2 library in Node.js. Specifically, it asks how to access sandbox properties or functions within modules required by the virtual machine. Key concepts include understanding how vm2 handles sandboxing and requiring external modules. Root Cause The root cause of … Read more

XCode – Validatition failed: Invalid Signature + Invalid bundle

Summary The validation failure in XCode occurs due to invalid signature and invalid bundle issues. This happens when the application is not signed with a distribution certificate or when the bundle contains disallowed files. Root Cause The root cause of this issue is: Incorrect code signing settings in Xcode Use of ad hoc or development … Read more

Performance issues with WS_DELIVERY_UPDATE – how to reduce performance time?

Summary The performance issue with WS_DELIVERY_UPDATE is causing significant delays in processing large outbound deliveries with multiple Handling Units (HUs). The function module’s consistency checks against all existing database entries and assigned HUs are leading to degraded performance as the number of HUs increases. Root Cause The root cause of the performance issue is: Excessive … Read more

How to check if a document is mongoose sub schema in middleware?

Summary The issue at hand is how to prevent a mongoose plugin from adding an organizationId field to sub-documents in a multi-tenant application. The current implementation uses a global plugin to handle adding organizationId during filters, saving, and aggregation, but it incorrectly adds this field to sub-documents. Root Cause The root cause of this issue … Read more

Can I mess up GCC hash seed of unordered_map?

Summary The issue at hand is related to the unordered_map in C++ and how its iteration order can affect the results of floating-point calculations due to floating-point rounding errors. The question revolves around whether it’s possible to manipulate the hash seed used by GCC for unordered_map to reproduce a specific iteration order without modifying the … Read more

How to securely automate TOTP MFA in CI/CD without exposing credentials?

Summary The goal of this article is to discuss how to securely automate Time-Based One-Time Password (TOTP) Multi-Factor Authentication (MFA) in CI/CD pipelines without exposing credentials. We will explore the challenges of automating TOTP MFA, including secret injection, state management, and bypassing MFA. Root Cause The root cause of the problem is the need to … Read more

Is my setup robust for Quant calculation engine, and should I use SQLAlchemy 2.0, or an alternative?

Summary The current setup for the FastAPI application, which serves as a core engine for a derivative trading and quant operations system, uses a relational database (e.g., PostgreSQL or MySQL) with SQLAlchemy for ORM and DB access. The application utilizes session-based DB interaction per request and has logging enabled for queries and application events. The … Read more