- React – Bootstrap
Two ways to use Bootstrap in React: the plain stylesheet with className, or react-bootstrap's real components. Why you should not load Bootstrap's JavaScript bundle alongside React, controlled modals and offcanvas drawers, and overriding the theme with custom properties instead of fighting specificity.
- Python Advanced – NumPy Arrays
The array that made Python a data language. Why it is faster than a list, shape and dtype, vectorised operations instead of loops, broadcasting, boolean masks, and the view-versus-copy distinction that causes the confusing bugs.
- Python – Testing
Writing tests with pytest — plain asserts, arranging and asserting, fixtures, parametrising instead of copy-pasting, and testing that something raises. What unittest looks like for when you meet it, and what is worth testing at all.
- Frontend Dev – Talking to the Backend
One request has four outcomes and beginners handle one of them. Building a single API layer instead of scattering fetch calls, turning an error response into something a component can render, loading and error and empty states, cancelling a request that no longer matters, and why CORS fails the way it does.
- Database
JDBC is the API every Java database access sits on — Hibernate, Spring Data, jOOQ and every ORM eventually call it. You will rarely write it directly, and knowing what it does is what lets you diagnose the layers above it. The shape Four objects: a Connection to the database, a PreparedStatement…