Why Joshfonseca Exists

Joshfonseca is a small independent blog about building software and the tools around it. It is written for working developers, people moving into the field, and curious readers who want to understand how apps and language models actually behave once they leave the demo stage.

Who reads it

The typical reader is shipping something: a web service, a side project, an internal tool or a mobile app. Some have years behind them and want a second view on one stubborn decision. Others are still learning and need a plain explanation without jargon piled on top.

Three subjects, one thread

• Software Engineering looks at design choices, testing habits, code review, debugging, maintenance and the trade-offs that decide whether a codebase stays pleasant to work in.
• Language Models covers how LLMs are used in real products, including prompting, evaluation, cost, latency, limits and the ways output can go wrong.
• Mobile Apps deals with building, releasing and improving apps on handheld devices and tablets, from performance and offline behaviour to store review rules.

These areas meet constantly. A mobile app may call a language model, and that call needs sound engineering around timeouts, errors and privacy.

The way articles are put together

Posts aim to be practical: something you can test in an afternoon. Technical claims are checked against official documentation, release notes, specifications and, where possible, a small experiment. When behaviour depends on a version, a platform or a model that changes often, the article says so instead of presenting a guess as settled fact.

Software ages quickly. Libraries are renamed, models are replaced and store policies shift, so older pages are revisited and updated when they stop being true.

Spotted an error?

If a snippet fails, a fact is out of date or a link is broken, write to [email protected]. A confirmed mistake is corrected directly in the post, so the next reader gets the working version.