Social Security Administration is a welfare program to directly give cash to those who are in need.

\begin{equation} softmax\qty(x_{i}) = \frac{\exp(x_{i})}{\sum_{j=1}^{n} \exp(x_{j})} \end{equation}

its “softmax”!

• max: amplifies the probability of the largest \(x_{i}\)
• soft: because it assign some probability to smaller \(x_{j}\) as well

:clap: What. Does. The. Client. Want.

Web Applications vs Local Application

• scale—what levels of functionality and access do we want
• training
• speed

SOLID principles

SOLID principles is a set of OOP principles; its kinda famous but encourages mindless braindead Java devs.

• Single Responsibility: that a class should have only one clearly defined thing it represents, and the class should only change IFF the underlying spec regarding that thing changes
  • Easy pitfalls: mixing PERSISTENCE LOGIC with BUSINESS LOGIC (db should be moved to a separate class like ThingProvider/ThingPersistence)
• Open-Close Principle: classes should be easily extendable and closed to modification
  • “we should be able to add new functionality without touching what’s written”
  • so like interfaces are nice
• Liskov Substitution Principle: subclasses should act like base classes (and more); good inheritance systems should have this built in
• Interface Segregation Principle: you should build lots of interfaces + sub-interfaces based on what clients are and will need, such that a client only has to extend precisely the amount needed to do their job
• Dependency Inversion Principle: when possible, depend on abstract classes or interfaces and not their implementations

Dependency Injection

“Dependency Injection” is a 25-dollar term for a 5-cent concept. […] Dependency injection means giving an object its instance variables. […].

Here’s a bit of a guide to start in software development. It is mostly links to other resources that would help.

Introductory Remarks

Nobody “learns” software development. Even in job interviews, people expect you to have “worked” in software development. The industry, as a whole, drives via “learn-by-doing”, so its best to start thinking about what you want to achieve with software dev in terms of projects, then look specifically for resources to help you achieve those. Once you Google enough, et viola! You will have the skills needed to tackle another project.

The software development models, or Software Development Life-cycles (SDLCs), are methodologies to approach organizing a software project.

Waterfall

The waterfall specification gets written before any code written. We hand off spec and code directly to tester, and code should behave like spec.

• Code specification exactly
• Spec does not update

Code happens only after stuff is done

Agile

Agile are designed to work with minimum specification before code. Spec is updated constantly as code changes and get user feedback.