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

Kubernetes 1.35 GA: an operations-side balance sheet

Kubernetes 1.35 GA consolidates three releases of work: native sidecars with full lifecycle management, generalised DRA for FPGAs and NPUs, and a scheduler that cuts resource waste by 15-25% in heterogeneous clusters. An operations-side balance sheet: what to enable now, what to watch before migrating, and what path to follow from 1.30.

Architecture

MCP as multi-vendor standard: patterns already mature

The Model Context Protocol, proposed by Anthropic in late 2024 and adopted through 2025-2026 by Anthropic, OpenAI, Google, and the open-source community, already has proven operational patterns: separating generic servers from custom ones, explicit per-tool policies, credentials kept outside the model, prefixed composition, and contract tests. This is the state of the art in 2026.

Architecture

Hybrid RAG in 2026: the patterns that keep winning

Hybrid RAG in 2026 combines dense and lexical search fused with RRF, cross-encoder reranking over the top-50 candidates, structure-aware chunking, and continuous evaluation with Ragas or TruLens. It is the pattern that survives in serious production systems three years after the initial embeddings boom.

Technology

XR, AR and VR in 2026: the honest state after the cycle

After the 2023-2024 hype cycle led by Apple Vision Pro, the 2025 valley of disillusionment, and the quiet but real consolidation of Meta Quest 3S and the WebXR stack, it is time to assess honestly where extended reality stands. What works, what has died, what is still alive.

Software Development

WASI preview 3: adoption and real cases

WASI preview 3 llegó como estándar estable a finales de 2025 y ha tenido unos meses para demostrar si realmente desbloquea los casos que preview 2 se quedaba cortos. Recorrido honesto por adopciones reales, bibliotecas maduras y patrones que empiezan a funcionar en producción.

Artificial Intelligence

UX for agents: first design consensus

After two years watching every product invent its own interface for talking to an agent, by January 2026 a stable design consensus is emerging about which patterns work, which do not, and what the average user already expects. Time to write down what has settled.

User Experience

European Accessibility Act: the first year in practice

La obligación del EAA entró en vigor el 28 de junio de 2025. Seis meses después tenemos ya primeros expedientes sancionadores, criterios de enforcement y lecciones operativas para equipos que aún corren detrás del calendario. Lo que sí se audita y lo que todavía no.

Architecture

gVisor: sandboxing for multi-tenant containers

gVisor interpone un kernel en espacio de usuario entre el contenedor y el anfitrión. Después de años en producción en Google y adopción creciente en plataformas serverless, merece una lectura honesta sobre cuándo compensa frente a microVMs y runtimes clásicos.

Architecture

Agent OS: the concept shaping the new stack layer

The term Agent OS has spent a year gaining traction across research and product circles. It describes a layer that goes well beyond an agent library: request scheduling, context management, persistent memory, and isolation. A look at the real state of that concept.

User Experience

Accessibility overlays: the 2025 criticisms explained

Accessibility overlays were sold as a magic fix for WCAG and the European EAA directive in one step. In 2025 lawsuits against them have grown and disabled users are speaking out more critically than ever. A look at why they fail and what to do instead.

Architecture

Kubernetes 1.34: a summary for teams with little time

Kubernetes 1.34 ships with Dynamic Resource Allocation (DRA) graduating to stable, scheduler improvements, and CEL-based mutating admission policies that replace webhooks. A practical rundown of what is safe to upgrade now, what can wait, and what actually changes for teams running production clusters.

Architecture

Delta Lake and Apache Iceberg: 2025 comparison

Open table formats over data lakes have moved from curiosity to backbone of many analytics architectures. Delta Lake 4.0 and Apache Iceberg 1.9 are the two with the most weight in 2025. We review where each one stands and which criteria make sense when choosing between them.

Software Development

Rust Edition 2024: what really changes day to day

Rust Edition 2024 became stable on February 20, 2025 alongside Rust 1.85. Seven weeks later, the changes that actually matter for daily work are three: more granular variable capture in closures and Return Position Impl Trait, an expanded prelude with Future and AsyncFn, and unsafe now mandatory in extern blocks.

Architecture

Applying graph RAG to a real product

Desde que Microsoft abrió GraphRAG, el patrón de usar grafos sobre tus propios datos ha pasado de experimento académico a técnica con aplicaciones prácticas. Reflexión sobre cuándo compensa, cómo se monta y qué errores se repiten.

Software Development

Full-stack TypeScript in 2025: the good, the meh, the bad

Full-stack TypeScript with Next.js and tRPC removes type duplication between frontend and backend, but it is not a universal answer: Node still falls short on CPU-bound loads, testing remains fragmented, and large projects eventually split apart. It is the best fit for small-to-medium products with agile teams, not for sustained high-performance systems.

Software Development

Python 3.12: Incremental Acceleration and Errors That Finally Help

Python 3.12, released in October 2023, brings inline generic syntax through PEP 695, tracebacks that pinpoint the exact error, and an average speedup of around 5% over 3.11 on pyperformance, plus experimental sub-interpreters with their own GIL. Migrating from 3.10 or 3.11 is straightforward: major libraries already ship compatible wheels.

Architecture

Model Context Protocol: Anthropic’s Open Proposal

Model Context Protocol (MCP) is the open standard Anthropic published on 25 November 2024 to connect language models with external data and tools over JSON-RPC 2.0. It does not replace function calling: it standardises the server side, aiming to become for context what the Language Server Protocol is for code editors.

Software Development

SvelteKit 1.0 a Year Later: Real Adoption and Limits

Almost two years after 1.0, SvelteKit works in production: 30-50% lighter bundles than React, file-based routing, and no-lock-in deployment. It wins for small teams with stack freedom; it loses to Next.js when a team has heavy existing React investment or needs to hire fast.

Software Development

Aider: AI for Refactoring from the Terminal

Aider is an open-source CLI that connects your Git repository to an LLM to refactor code, add features and fix bugs without leaving the terminal. Works with GPT-4o, Claude and local models via Ollama. Every change generates an automatic commit with a descriptive message, integrating natively into the Git workflow.

Architecture

Container Monitoring: Beyond cAdvisor

cAdvisor is still embedded in kubelet and covers surface metrics, but falls short for production Kubernetes. The modern minimum stack pairs it with kube-state-metrics, node-exporter, Prometheus, and Grafana as a base, eBPF for deep network and syscall visibility, and OpenTelemetry for application context.

Architecture

Cilium Service Mesh: When You Don’t Need Sidecars

Cilium Service Mesh replaces Istio or Linkerd sidecars with eBPF in the kernel: it handles policy, WireGuard encryption, and Hubble observability without a per-pod proxy, cutting memory overhead from roughly 100 GB to about 5 GB in a 100-node cluster. It suits large clusters with teams comfortable with eBPF.

User Experience

WCAG 2.2: What the New Accessibility Version Brings

WCAG 2.2 (W3C, October 5, 2023) adds 9 criteria to WCAG 2.1: Target Size requires clickable targets of at least 24 by 24 pixels, and Accessible Authentication bans logins that require memorising complex passwords without an alternative. Upgrading from 2.1 AA typically takes 1 to 2 sprints for a medium-size product.

Software Development

TypeScript 5.4: More Powerful Types, Fewer Tricks

TypeScript 5.4, released March 6 2024, adds NoInfer to pin generic type inference without the two-parameter workaround, preserves narrowing inside synchronous callbacks like forEach and map, and ships typed Object.groupBy and Map.groupBy. Three everyday workarounds quietly retired in one incremental release.

Architecture

How to Install PostgreSQL with pgvector Step by Step

This guide installs PostgreSQL 16 with pgvector on Debian or Ubuntu using the official PGDG repository, creates a dedicated role and database, tunes memory for production, and explains when the HNSW index beats IVFFlat depending on vector volume and the available maintenance window.

Architecture

Backstage, Port and Cortex: Three Paths to the IDP

An Internal Developer Platform (IDP) centralises service discovery, provisioning and observability in a single portal, so developers stop depending on stale wikis and Slack channels. Backstage, Port and Cortex dominate the market: Backstage is open source with a dedicated team, Port is fast low-code SaaS, and Cortex focuses on scorecards for measurable technical discipline based on team size.

Architecture

SQLite and DuckDB: When Each Is the Right Choice

SQLite and DuckDB are both embedded databases that work from a single file, no server needed. Their architecture differs: SQLite stores rows and excels at short transactions (OLTP); DuckDB stores columns and shines at large-scale analytics (OLAP). Choosing the right one, or combining both, delivers a genuine technical edge.

Architecture

Service Mesh in 2023: Istio, Linkerd, and the Cilium Option

A service mesh adds mTLS, uniform observability, and traffic management between microservices without modifying application code. The ecosystem has consolidated: Istio is the most complete and complex, Linkerd prioritises simplicity with Rust proxies, and Cilium delivers sidecarless service mesh via eBPF.

Software Development

Rust in the Linux Kernel: First Steps and Controversies

Rust has been in the Linux kernel since version 6.1, though adoption is measured and deliberate. The Apple AGX GPU driver for Asahi Linux is the most prominent real upstream example. The goal is to eliminate an entire class of memory-safety bugs in new drivers without rewriting existing C code.

Software Development

Rust for Backend: axum and tokio in Real Services

Rust is no longer just a systems language: with tokio as the async runtime and axum as the HTTP framework, teams build high-performance backend services with compile-time type checking. It pays off in gateways, proxies and event processors; for typical CRUD over Postgres, Go or Node.js remain more productive.

Architecture

Kubernetes 1.27: The Changes That Matter to Operators

Kubernetes 1.27 ("Chill Vibes"), released in April 2023, makes SeccompDefault stable so pods get safer syscall defaults automatically, moves KMS v2 to beta with rotatable encryption keys for etcd secrets, and stabilises scheduling gates. It also removes PodSecurityPolicy for good: without migrating to Pod Security Admission first, the upgrade is blocked entirely.

Architecture

Kafka in 2023: Event Streaming in the Enterprise

Apache Kafka has consolidated in 2023 as the enterprise event backbone thanks to KRaft, now GA and removing the ZooKeeper dependency. The most mature patterns are CDC with Debezium, event sourcing, and stream processing with Kafka Streams or Flink, while Redpanda and Pulsar compete as real alternatives depending on the case.

Architecture

OpenTelemetry: Unifying Logs, Metrics, and Traces

OpenTelemetry is the CNCF project, graduated in May 2026, that unifies logs, metrics, and traces under one SDK and the OTLP protocol, without locking you into a single backend. Traces have been stable since 2021 and metrics since 2023; logs are still maturing, but already worth adopting on new projects.

Architecture

Cilium and the Future of Container Networking with eBPF

Cilium replaces iptables with eBPF programs loaded directly into the Linux kernel, substituting O(n) linear chains with O(1) hash lookups. Documented benchmarks show up to 50% lower p95 latency, 2-3x more throughput, and 70% less kernel CPU in large Kubernetes clusters.

Architecture

RabbitMQ for Message Queues: When It’s Still the Choice

Kafka gets the headlines as the byword for modern messaging, but RabbitMQ remains the better choice for task queues with retries, asynchronous RPC, and pub/sub with complex routing. This guide compares both against NATS, walks through classic patterns and production mistakes, and helps you decide based on the actual use case rather than the trend.

Methodologies

Contract Testing with Pact for Microservices

With 30 or more microservices, end-to-end tests become slow, fragile and impractical. Pact implements consumer-driven contract testing: the consumer defines what it expects, the provider verifies it in its own CI pipeline, with no shared environment needed. The result is integration proof in seconds, not minutes.

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.

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

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.