# Writing Better Apps: Dependency Injection

Dependency Injection (DI) is a pattern where the "things" a component (function, class) depend on are passed into the component instead of the component trying to instantiate (or resolve it) itself. This practice tends to make code a lot more robust by reducing a component's scope. The DI pattern also simplifies the testing . . .

April 24, 2021

# Writing Better Apps: Implementing Configuration

"Configuration" is the settings your application uses to change its behavior at runtime. Configuration might include simple values that adjust timeouts on requests to more complicated settings that swap out database or cloud service providers.

The process of collecting and validating configuration is critical to a stable . . .

September 30, 2020

# Writing Better Apps: Initialization

Whether you are writing a script, a multicommand CLI utility, or a networked server, applications should follow the same initialization pattern:

• Get configuration
• Build dependencies
• Resolve and execute the entry-point function

### Get configuration

Using the environment, and possibly command line . . .

Posted in: nodejstypescript

September 19, 2020

# Thoughts on using Kafka with Node.js (node-rdkafka)

Let me start by saying, node-rdkafka is a godsend. When we first started using it, the library was the only one fully compatible with the latest version of Kafka and the SSL and SASL features. I owe webmakersteve and other contributors all a six-pack of beer for making this possible (thank you!!!!).

With that said, I guarantee you . . .

April 01, 2020

# Avoid Synchronous Functions in Node.js

## tl;dr

Most synchronous methods in Node.js (statSync, readFileSync, etc.) have asynchronous alternatives (via callback). Using util.promisify can easily make these methods async/await compatible. Using the Promise-based equivalents can greatly speed up your application. In fact, I'd argue there's never a need for the . . .

Posted in: nodejstypescript

February 29, 2020

# Distributed Locking with Postgres Advisory Locks

#### TL;DR

Postgres Advisory Locks are a great solution for arbitrary application locks, particularly in scenarios where you are already using Postgres and have a need to block concurrent mutations to a resource (that resource DOES NOT have to be data in Postgres).

# Concurrency is hard

We ran into a problem . . .

February 16, 2020

# WebSequenceDiagrams.com TypeScript Client

### https://gist.github.com/rclayton-the-terrible/493cd0811542ff9693ac02746517ba71

TL;DR - TypeScript Client Gist: https://gist.github.com/rclayton-the-terrible/493cd0811542ff9693ac02746517ba71

If you are not familiar with WebSequenceDiagrams, it's an excellent tool for creating sequence diagrams for planning software flows. If you are not familiar with sequence diagrams, a quick Google search will . . .

June 22, 2019