Backend

WebRTC avoids carrying media through the Java API, but browsers still need connectivity, NAT traversal, and sometimes relay infrastructure. An example service therefore keeps the text room as the source of truth and tre…

The Java API and Python voice engine are separate processes, so a protobuf contract makes change and failure more explicit than an untyped internal call. voice/v1/voice.proto defines synthesis, the voice catalog, and ca…

The absence of an exception does not mean that a scheduled job succeeded. When jobs catch errors and return None, error, counts, or partial states, monitoring cannot distinguish normal empty work from a failure.

An HTTP request ends when it returns a response, while a Kafka job may finish later. Pass a separate correlation header instead of changing the business JSON, so the flow remains traceable without breaking the payload c…

Calling a public-sector or third-party OpenAPI directly from the client gets the first screen up quickly. Run it for a few days, though, and the same kinds of incidents repeat — leaked keys, surprising result codes, pro…

Signup confirmation, password reset, one-time verification codes — when a service needs to send something directly to a user, email is usually the first channel it reaches for. Unlike push notifications, it needs no sep…

In a backend with admin capabilities, capturing who-when-what-why is more than mere tradition. It is how you satisfy privacy law (PIPA · GDPR), investigate incidents, and deter privilege misuse.

HTTP is fundamentally a one-request-then-one-response model. It is hard for the server to speak to the client first. In places like chat, notifications, and live updates, the server must be able to push data actively.

When writing an API on top of HTTP, REST is the word that comes up most often. It stands for Representational State Transfer, organized in Roy Fielding's 2000 doctoral dissertation.

There is a standard for expressing the shape of an HTTP API as a machine-readable document. That is the OpenAPI Specification (OAS). Once it is written well, doc pages, client SDKs, mocks, and contract tests all flow fr…

Collecting public web data touches not only technology but ethics and law. Hitting too often burdens the target server, and skipping the terms of service can spill into legal trouble.

TypeORM was once a representative ORM in the Node camp and was widely used alongside NestJS. Its position has shifted somewhat as new ORMs appeared, but it still runs in many codebases.

Periodic tasks show up in any backend. Nightly aggregates, external data collection, expired-token cleanup. At small scale, cron or an in-process scheduler is enough; at larger scale, distributed queues and workers appe…

When writing an HTTP API, the code around the handler body (auth, validation, logging, error translation, rate limiting) often outweighs the body itself. Where and how this cross-cutting code lives decides consistency a…

Where should the schema's truth live? ORM models, migration files, DDL SQL — there are several candidates. We compare the cumulative-migration model with the single-SQL-file + CREATE IF NOT EXISTS model.

In Python web backends, frameworks rarely enforce a folder layout, so it falls to team agreement. A well-organized layout shortens onboarding for new members; without it, the same patterns get scattered everywhere.

FastAPI moved into the Python web framework mainstream in a relatively short time. Behind that quick rise is a design that ties type hints, Pydantic, and async into a single coherent sentence.

Spring carries two web stacks side by side. The older Spring MVC (Servlet-based, synchronous and blocking) and the relatively newer Spring WebFlux (Reactor-based, asynchronous and non-blocking).

When several Spring applications live in a single repository, we have to settle the location of shared code, the build unit, and the direction of dependencies. Gradle's multi-project build is the standard tool for handl…