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

Agent-to-agent protocols: the next open layer

With MCP solving the agent-to-tool layer, a parallel problem surfaces: how do two agents from different vendors communicate with each other. Google's Agent2Agent protocol, donated to the Linux Foundation in June 2025, tries to fill that gap with an open standard.

Architecture

Inference routers: choosing a model based on the request

Un enrutador de inferencia decide qué modelo atiende cada petición en función de coste, latencia y complejidad. Bien diseñados reducen la factura de tokens sin que el usuario perciba degradación; mal diseñados introducen fallos sutiles difíciles de depurar.

Architecture

TigerBeetle: a database built for financial transactions

TigerBeetle is a distributed database written in Zig, specialized in one specific kind of workload: high-volume double-entry accounting with strong consistency guarantees. It does not aim to replace Postgres; it aims to be the right tool when the problem is counting financial transactions at millions per second without subtle failures.

Architecture

Platform engineering: consolidation after the boom

After three years of expansion and an overheated ecosystem around the term, platform engineering enters 2025 in a consolidation phase. The internal platforms that survive are the ones that understood their real function; those that mistook the label for the solution are dismantling their teams or cutting them drastically.

Architecture

Citus: scaling Postgres horizontally without leaving it

Tras la adquisición por Microsoft en 2019, Citus vivió un limbo comercial que terminó con Microsoft abriendo el código completo en 2022. Tres años después, la extensión de particionado para Postgres ha madurado y ofrece una ruta práctica para escalar sin abandonar el motor que ya conoces. Un repaso honesto.

Architecture

SQLite in production: patterns that have aged well

SQLite lleva años ganando terreno en servidores reales gracias a WAL, a proyectos como Litestream y libSQL, y a hardware con discos rápidos. Repaso los patrones que siguen funcionando después de varios años de uso, los que no, y por qué el tamaño medio de una aplicación web se come ya sin despeinarse.

Architecture

DuckDB in enterprise analytics: concrete cases

DuckDB has spent two or three years quietly working its way into data architectures. It is no longer just the embedded database for local analytics: in 2025 it keeps turning up in concrete enterprise cases where it replaces far pricier pieces. A tour of the real patterns.

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.

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

containerd 2.0 in production: real migrations

Six months after containerd 2.0 reached general availability there is enough real-world mileage to judge the migration from the 1.x branch in production. We cover what changes in the config file, what breaks on Kubernetes and Docker Swarm, and when planning the jump actually pays off.

Architecture

Firecracker: microVMs for multi-tenant services

Firecracker is the Rust-based virtual machine monitor AWS uses in Lambda and Fargate: it boots microVMs in under 125 milliseconds with under 5 MB of overhead. Switching from containers pays off when a shared kernel does not give enough isolation, especially for untrusted LLM agent code, and versus gVisor it wins on I/O performance.

Architecture

Coolify: a self-hosted Vercel on your own infrastructure

Coolify delivers a Vercel- or Heroku-like experience on your own servers: automatic HTTPS, managed databases, and branch previews without per-build or bandwidth fees. After several months using it on production VPS, here is where it shines, where it still has rough edges, and which teams will genuinely benefit from it.

Architecture

Microsoft’s GraphRAG in enterprise: patterns that work

GraphRAG has been in real enterprise use for over a year: during indexing, an LLM builds a knowledge graph that answers global questions about a corpus well, precisely where classic RAG fails because no single chunk holds the full answer. Here I compare indexing costs, the cases where it pays off, and the hybrid pattern that teams have settled on.

Architecture

Cloudflare Workers in 2025: from edge to enterprise

Cloudflare Workers turned eight in 2025 without slowing down: it now ships D1 for databases, R2 for egress-free storage, Durable Objects for distributed state, and Workers AI for running models without managing GPUs. It remains the fastest option for edge logic; for large in-memory processes or strict global consistency, other platforms fit better.