Custom Software
We build the technical application you need.
Reinventwhatcould beyour business
Active
Leading change through custom software, generative AI and robust architecture.
Start your project
Cybersecurity
Armored security for critical infrastructure.
Generative AI
Redefining workflows with cognitive agents.
Dev & UX
Web & App development with top conversion rates.
Trusted By Enterprise
Arval
Sabadell
GasNatural
Vueling
Arval
Sabadell
GasNatural
Vueling
Arval
Sabadell
GasNatural
Vueling
Arval
Sabadell
GasNatural
Vueling
Arval
Sabadell
GasNatural
Vueling
Arval
Sabadell
GasNatural
Vueling
Arval
Sabadell
GasNatural
Vueling
Arval
Sabadell
GasNatural
Vueling
Why Xtremis
We're not your
typical consultancy.
While other consultancies sell you hours, we sell you outcomes. Every project has one goal: measurable ROI from the first delivery.
Discover how we do it72h
From idea to prototype
Your concept turned into a functional prototype validated with real users before investing a euro in development.
10x
More code per engineer
Proprietary AI agents that generate, test and document in parallel. Your team ships in 1 day what used to take 2 weeks.
0
Team turnover
Same senior team from start to finish. No juniors rotating, no re-onboarding. Your business context is never lost.
€0
Inherited tech debt
Clean code with 95%+ test coverage. When another team inherits it, they can keep building without rewriting anything.
Methodology
From vision to
Critical Deployment.
Consulting & Audit
We analyze your legacy infrastructure and corporate requirements, identifying bottlenecks and designing the migration strategy.
Architecture & Design
We draw technical blueprints based on microservices and DDD patterns to ensure the system scales in the future.
Intensive Development
Iterative product coding with continuous integrations, automated tests (BDD) and parallel RAG/AI model injection.
Deployment & Scale
We go to production via Kubernetes and AWS in a secure and automated way, with built-in telemetry ready to scale enormously.
New Paradigm
Augmented
Engineering.
We don't code like 5 years ago. The entire development cycle at Xtremis is powered by our own generative AI ecosystem.
- Custom MCPs: Agents trained on our architecture.
- Context RAG: The AI knows your entire code and test history.
- Zero Drift: Documentation that updates autonomously.
Xtremis Orchestrator MCP
System: "Contextualizing monorepo structure..."
[RAG Engine] Loaded 2,403 architectural tokens.
Agent_01: Analyzing test coverage gaps...
» Proposed mutation: Retry fallback in EventBus.
import { Injectable, inject } from '@angular/core';
@Injectable({ providedIn: 'root' })
export class AiContextGuard {
private readonly rag = inject(LocalStoreEngine);
}
Our Insights
Leadership in
Engineering.
Software Engineering
8 min read
The end of the monolith: Safe transition to Go microservices.
How we design architectures with Go and gRPC to scale critical eCommerce platforms and reduce cloud costs.
Read Article
Cybersecurity
6 min read
Securing the software supply chain (CI/CD).
Mandatory DevSecOps practices to prevent breaches from source code to cloud in automated deployments.
Read Article
Generative AI
5 min read
RAG integration over sensitive on-premise data.
Why large corporations don't use open AI APIs and how to set up LlamaIndex and local LLMs for private analytics.
Read Article
Executive Perspective
Trust Based on
Pure Results.
"
"The difference between a traditional agency and Xtremis is radical. They not only rewrote our core platform from scratch, but the deployed architecture withstood a peak of 1.2 million requests per minute on Black Fridaywithout latency. It's pure authorial engineering."
David Miller
CTO, Global Tech Retail
"
"Our AWS infrastructure costs were drowning profitability. The cloud architecture team refactored our monoliths into Go and Kubernetes microservices and the bill dropped 42% in the first cycle. Brutal, measurable ROI."
Elena Rostova
VP Engineering, FinTech Ops
Our Philosophy
We design & build the software you need.
Does your company need to improve its technology with comprehensive, custom software? We do it from Barcelona, efficiently, reducing costs and improving responsiveness to change.
Meet the team01 Software Quality
We use the best development technology to make your system effective, powerful and of superior structural quality.
02 Scalability
The future of your project matters to us. We make it easy for your application to adapt and grow to meet new needs.
03 Maintainability
We develop strongly tested code and clean architectures to guarantee long-term maintenance decisively.
Digital Services
Innovation applied to every layer of your company. From cloud architecture to cognitive intelligence.
Computer Consultancy
We ease your IT integration
We guide you in modernizing critical infrastructure, designing resilient systems, and operationally efficient cloud migrations (AWS/Azure).
Mobile App Development
We build the application you need
We create native and hybrid applications with exceptional performance and UX highly focused on mobile user retention and recurrence.
Web Development
UX, SEO & High Conversion
Ultra-fast web portals that dominate search engines, focused on organic acquisition and aesthetically designed to generate B2B authority.
Our Track Record
Case
Studies.
Custom Software
Arval Car Sharing
Global B2B vehicle fleet transformation
We built the comprehensive platform connecting real-time telemetry with a Vue + Django architecture and React Native app operating thousands of corporate vehicles across Europe.
+45%
Usage efficiency
3M+
IoT trips
100%
AWS Uptime
Top Development Agency in Spain
Local operations.
Massive Global Impact.
We consolidate our position as the leading B2B provider of Custom Software Development in Barcelona and Bilbao. Extreme Web Applications, Cognitive AI (RAG) and Zero-Trust Cybersecurity covering critical needs of medium and large enterprises.
Innovation & UX Hub
Barcelona
Our headquarters in Catalonia centralizes digital interface design, B2B corporate marketing and local SEO strategies for top companies in the Iberian and international sectors.
Custom Software Engineering
Bilbao
From the industrial heart of the Basque Country, we develop robust architectures, advanced cybersecurity and complex system integrations (ERP, CRM) for intensive corporations.
Cloud & AI Operations
Global
We operate 100% cloud-native infrastructures and RAG networks for artificial intelligence without geographical borders, providing uninterrupted service to clients in LATAM, USA and Europe.
Future
Ready
Let's build your next great innovation success today. Designed from Barcelona, operating globally.
Request Free ConsultationContact
Let's talk about
your Project.
Over 25 years transforming businesses with custom software. Tell us your challenge and we'll design the solution.