06/11/2026 updated
partially available
info: Available evenings and weekends
AI Systems & Backend Engineer — RAG, LLM Pipelines, Production APIs
Coimbra, Continental Portugal, Portugal
Only remote
BSc Computer Science Engineering About me
Backend & AI Systems Engineer. I build production RAG and LLM pipelines, evaluation frameworks, and reliable APIs — from prototype to running in production. Focused on correctness, clean data flows, and systems you can actually maintain. Remote (40–60%).
PostgreSQLRemote SupportBackendBackend Programming
Backend Development
Design and implementation of backend systems with a focus on correctness, maintainability, and clear ownership. Experience delivering production services used by real users.
API Development
Design and implementation of RESTful APIs with explicit data contracts, validation, and documentation. Emphasis on predictable behavior and long-term maintenance.
Databases & Data Handling
Experience designing and operating relational databases (PostgreSQL, MySQL) and in-memory stores (Redis). Focus on data integrity, performance, and operational clarity.
Async & Data Processing
Background in building and maintaining data-intensive systems, including large-scale data processing and performance optimization.
Infrastructure & Deployment
Containerized services using Docker, with CI/CD pipelines and production deployments. Preference for simple, observable systems over unnecessary complexity.
Collaboration & Delivery
Used to working in remote, asynchronous teams with clear communication, version control, and responsibility for delivered work.
Experience
Professional experience0 - 5 years
Freelancer since2024
Languages
EnglishGoodPortugueseNative speaker
Project history
Embedded engineer on a production AI document-assistant platform. Built parallel RAG retrieval architecture, an LLM evaluation framework (Langfuse) covering hallucination, tool-misuse, and instruction-following, and multilingual support across 60+ languages. Delivered a video dubbing pipeline (Azure Speech) and led ISO 27001 security remediation. Shared CTO-level technical escalation on a rotating basis.
Designed and implemented backend infrastructure from scratch, including REST API endpoints, relational database schema, and authentication workflows. Integrated PostgreSQL with Node.js backend for real-time data storage and developed AI-powered features using OpenAI APIs
Designed and implemented a blockchain data extraction system in Python, processing over 500 million Bitcoin transactions into a hybrid PostgreSQL + Redis database architecture. Achieved dramatic performance improvements processing hundreds of millions of records in 3 days