Categories

Jacar categories — explore the topics A rocket whose eyes follow your cursor.
Architecture

Kubernetes 1.28: Sidecar Containers as First-Class Citizens

Kubernetes 1.28 introduces native sidecar containers in alpha via KEP-753: adding restartPolicy Always to initContainers ensures correct startup and shutdown ordering. It fixes Jobs that never terminate. Istio, Linkerd, and observability agents like Fluent Bit are the primary beneficiaries.

Artificial Intelligence

LLM Fine-Tuning: When It’s Worth Training Your Own

Fine-tuning your own LLM pays off in three cases: you need a very specific style or voice, a rigid structured output format, or you want lower cost and latency from a small specialised model. LoRA and QLoRA have cut the GPU cost, but preparing data and running the model in production are still expensive. For everything else, RAG and prompt engineering are usually enough.

Tools

Figma: Collaborative Prototyping for Product Teams

How Figma went from being one more design tool to becoming the shared language between design, product and engineering, and what that shift changes about the way a product team actually works from the first sketch through to handoff.

Architecture

Pixie: Native Kubernetes Observability Powered by eBPF

Pixie uses eBPF to automatically instrument Kubernetes clusters without modifying application code. A per-node agent captures HTTP, gRPC, SQL, and Redis traffic at the kernel level, exposing service maps, CPU profiles, and SQL traces within minutes. It complements Prometheus for reactive diagnosis with no sidecars or redeploys.

Artificial Intelligence

OpenAI Code Interpreter: Conversational Data Analysis

OpenAI Code Interpreter extends ChatGPT Plus with an isolated Python sandbox: it runs code on demand, reads files you upload (CSV, Excel, PDF, images, ZIPs) and returns results plus charts within the same chat. Sessions are ephemeral and offline, but remarkably effective for exploratory ad-hoc analysis without spinning up a notebook.

Architecture

From Monolith to Microservices: Transforming the Architecture

Migrating from monolith to microservices means splitting a single system into independent services that deploy and scale on their own. It gains granular scalability and team autonomy, but adds real operational complexity: stable interfaces, Kubernetes orchestration, and a mature DevOps culture are conditions, not optional extras, for the migration to pay off.

Industry 4.0

The Customer Digital Twin: A Strategic Tool

The customer digital twin is a dynamic virtual representation of a real user, built from behavioural data, preferences, and interactions and updated in real time. Unlike a static CRM profile, it anticipates needs, personalises experiences at scale, and supports proactive decisions about each customer relationship.

Architecture

Modules vs. Microservices: The Architecture Battle

Choose modular architecture when your team has fewer than ten people and ships the system as a single unit; choose microservices when separate teams need to deploy independently or when specific components require very different scaling, in exchange for higher operational complexity.

Software Development

Word Choice in Your App: Key to the User Experience

The words in an application are not decoration: they determine whether the user completes the task or abandons it in frustration. Good UX writing demands clarity above all, consistent vocabulary across the interface, tone matched to the audience, and error messages that explain what failed and how to fix it, not just that something went wrong.