Marcos Finkielsztajn
Valencia, Spain · ES / EN
Full-Stack
Developer.
Backend Engineering · Business Systems · AI Integration
I build web applications and backend services that solve real problems through APIs, data, external integrations and asynchronous processing.
Featured project · Recurring business use
AMXpress Platform
Angular · NestJS · PostgreSQL · Redis · BullMQ
A logistics platform connecting administration, customers and courier workflows through APIs, integrations and asynchronous processing.
Explore Legacy SyncSystems I build
Four products. Clear interfaces, business logic and the services behind them.
Mobile-first product · Transactional rules
Kender Club
A mobile-first application for editorial discovery, partner businesses and benefits, with QR/NFC points and management dashboards.
Angular · NestJS · TypeScript · PostgreSQL · Prisma
Explore the case studyAutomation · Job search
Kairo
A platform for discovering, monitoring and managing job opportunities with explainable matching and supervised applications.
Next.js · React · NestJS · TypeScript · PostgreSQL
Explore the case studyApplied AI · Operational assistance
MAX Assistant
A web/PWA assistant for couriers that separates conversations, knowledge retrieval, decisions, generation and operational tools.
Angular PWA · NestJS · TypeScript · PostgreSQL · Prisma
Explore the case studyTechnical skills
From the data model to the interface. Backend as a specialty, product as context.
Backend & APIs
TypeScript · Node.js · NestJS. REST APIs, authentication, permissions, integrations and independent services.
Data & processing
PostgreSQL · Prisma · Redis · BullMQ. Transactions, workers, jobs and legacy system synchronization.
Frontend
Angular · React · Next.js. Responsive interfaces, applications for multiple roles and mobile-first experiences.
Infrastructure & quality
Docker · Linux · Git. Unit and integration tests, reproducible builds, deployment and maintenance.
Applied AI
OpenAI API · RAG · Embeddings · pgvector. Hybrid retrieval, structured outputs and workflows with human control.
Experience & specialization
Building around real operations
At AMXpress I work on business workflows used recurrently: connecting role-specific applications, APIs and integrations to an existing system. That experience informs my work on products with transactional rules, automation and applied AI.
My focus: understand the business rule, protect the data and make the system operable.
Let’s talk about your team
Open to full-stack and backend opportunities, freelance or full-time.