Julian Ortega

Staff Engineer, Search & AI Platforms

Building agentic AI products for top e-commerce platforms

15 years building search and AI platforms at a leading e-commerce platform through four acquisitions, from R&D intern to Staff Engineer. I architect discovery systems for enterprise retailers like ASOS, Adidas, and Harrods, and I lead the teams that ship them.

I take ambiguous technical bets from prototype to production, integrate acquired capabilities into existing platforms, and set the engineering standards that keep things coherent through growth and change.

I go deep on technical problems and wide on organizational, cultural, and process ones. I care about building high-performing teams and healthy engineering cultures, and I believe that technical excellence and organizational value creation go hand in hand.

Netherlands or Remote: EU Citizen
Spanish Native English Professional C2
Open to talk
LinkedIn GitHub
Julian Ortega - Profile Photo
Technical Excellence
  • Built AI search adopted by 30+ enterprise retailers across 40+ languages
  • Architected discovery platforms serving 200+ international retailers
  • Designed K8s migrations, search engine rewrites, and ML integration pipelines
Leadership & Impact
  • Led teams of 3-8 engineers through 4 acquisitions without losing continuity
  • Founded the Software Architecture Group, setting standards across 5 product lines
  • 70% of direct reports promoted during tenure; hired across 3 countries
Business Acumen
  • Built AI product that surfaced upsell opportunities during customer trials
  • Unlocked enterprise-scale catalogues, enabling larger customer acquisitions
  • Wore team lead, PM, and architect hats simultaneously for 2 years on a critical project

Technical Skills

Expert Advanced Proficient
Search, Retrieval & Ranking
Information Retrieval Ranking Systems Vector Search Semantic Search Hybrid Search (BM25 + dense) Embedding Models Recommendation Systems Personalization Systems Collaborative Filtering Matrix Factorization Evaluation Metrics (nDCG, MAP, AUC, R-Precision) A/B Testing & Experimentation NLP
Agentic & Generative AI
Agentic AI Systems LLMs RAG Multi-step Retrieval Tool Use & Function Calling MCP Conversational AI Prompt Engineering AI-Assisted Development (Claude Code) Multimodal LLMs (Gemini, Vertex AI) Evaluation Frameworks for Agentic Systems
Machine Learning & Deep Learning
Machine Learning Deep Learning Neural Networks Transformer-based Models (applied)
Programming & Development
Python Java RESTful APIs SQL FastAPI gRPC OpenAPI TDD Scala
ML Infrastructure & Data
Elasticsearch / Lucene Docker OpenSearch Kubernetes (GKE) GCP AWS CI/CD Helm ArgoCD / Argo Workflows Kafka Apache Storm ETL Pipelines & Feature Pipelines PostgreSQL Real-time Model Serving Prometheus & Monitoring Terraform Apache Spark DynamoDB Redis
Leadership & Craft
Mentoring Cross-functional Collaboration System Design Microservices Distributed Systems Performance Optimization

Professional Experience

December 2025 - Present

Staff Engineer

Rezolve Ai (Fredhopper B.V.)
Amsterdam, Netherlands
Staff Engineer in the Product Discovery team, shipping agentic AI and hybrid retrieval systems while leading the migration of search infrastructure to Kubernetes.
  • Shipped hybrid search combining BM25 with BGE-M3 dense retrieval across the search platform, with hot-swap rollout discipline and zero downtime to upstream systems
  • Laid the foundation for an agentic merchandiser: LLMs plan, query, refine, and reason over the search and merchandising surface via tool calls
  • Designed and built a working PoC of the K8s migration for a core search service of 500+ servers requiring zero downtime or upstream changes
Python Java LLMs BGE-M3 Vector Search Hybrid Search Agentic Systems Tool Calling Kubernetes ArgoCD Argo Workflows Helm Docker AWS Microservices Event-Driven Architecture
January 2025 - November 2025

Staff Engineer

Crownpeak (Fredhopper B.V.)
Amsterdam, Netherlands
Shipped three production initiatives spanning agentic AI, knowledge retrieval, and ranking systems. Took ambiguous technical bets from research through production with measurable business outcomes.
  • Evolved conversational commerce from research to production, adopting a single-agent-with-tools architecture at 20x lower LLM cost than the initial vendor; the pattern was later validated as the approach adopted by leading AI providers
  • Contributed an open-source plugin PR merged upstream to dify-official-plugins, enabling the agent to reason using customer search and merchandising engines
  • Built AI knowledge assistants targeting ~18% of all support ticket volume, with internal trial validating ~80% documentation coverage and a 30% ticket deflection target; the evaluation harness was its own workstream and shipped before the feature
  • Led architectural redesign of the suggestion ranking system, reducing index processing times by 64-93% (Swarovski 7h42m to 31m) and improving suggestion relevance by 15-18% in customer quality testing
  • Owned service lifecycle end-to-end: model deployment, real-time inference monitoring, CI/CD, evaluation metrics, and cross-functional delivery
Python Java FastAPI LLMs RAG Agentic Systems MCP Dify Langgraph Gemini OpenAI AWS Bedrock Vertex AI Conversational AI Vector Search Semantic Search Lucene Kubernetes ArgoCD Docker Microservices Evaluation Metrics Real-time Inference
Apr 2020 - Dec 2024

Software Architect

Attraqt (Fredhopper B.V.)
Amsterdam, Netherlands
Led the AI Search programme across text search, visual recommendations, product tagging, autocomplete, and reverse image search. Drove technology transfer from an acquired AI company, delivering a hybrid search engine combining vector and traditional retrieval, and an AI Search plugin using shared embedding technology for vector-based retrieval.
  • Architected and shipped AI-powered semantic search adopted by enterprise retailers across fashion, sports, grocery, and DIY verticals, supporting 40+ languages
  • Led vector search scaling investigation across 4 backends, identifying the cost-viable architecture for enterprise-scale catalogues
  • Built serving infrastructure handling 100x traffic spikes (5K to 500K rpm) through autoscaling architecture validated during production incidents
  • Drove CI/CD optimization delivering 3x build speedup at lower infrastructure cost across the engineering organization
Python Java Kotlin Scala Neural Networks Deep Learning Vector Search Semantic Search Embedding Models Elasticsearch OpenSearch GKE GCP gRPC Microservices Distributed Systems Information Retrieval Recommendation Systems
Apr 2016 - Apr 2020

Team Leader / Line Manager

Attraqt (Fredhopper B.V.)
Amsterdam, Netherlands
Led development teams of 3-5 engineers while driving two major platform initiatives: the Adaptive Personalization Engine and the Search Modernization project.
  • Designed and shipped the Adaptive Personalization Engine (APE) from PoC to production, a microservices architecture with 6 core components processing real-time user activity streams at 200+ events/second across 4 major releases
  • Delivered personalized product recommendations and search re-ranking while maintaining search response impact under 50ms average
  • Initiated and led the search modernization project, reducing reindex times from 2+ hours to 26 minutes and improving search response from 192ms to 130ms; achieved 99.8% of queries under 200ms
  • Mentored junior developers and facilitated career growth, with 70% of team members receiving promotions during tenure
Java Python Apache Storm Apache Kafka Apache Spark Kubernetes Docker AWS DynamoDB Elasticsearch Collaborative Filtering A/B Testing Experimental Design Microservices
Apr 2015 - Apr 2016

Senior Software Engineer

SDL (Fredhopper B.V.)
Amsterdam, Netherlands
Senior Software Engineer focused on developing e-commerce search and recommendation solutions while bridging research and practical implementation.
  • Created real-time recommendations engine proof of concept, integrating it into the core e-commerce product and establishing the foundation for production recommendation systems
  • Optimized product catalog ETL processes for 32M+ product catalogues, reducing reindexing time from 40 hours to 4 hours
Java Pentaho PDI ETL Optimization Real-time Systems Machine Learning Recommendation Systems
May 2012 - Apr 2015

Software Engineer

SDL (Fredhopper B.V.)
Amsterdam, Netherlands
Software Engineer working on search and recommendation technologies while contributing to research and development initiatives.
  • Developed and maintained search and recommendation algorithms processing terabytes of e-commerce data
  • Implemented collaborative filtering techniques that improved recommendation accuracy across multiple client implementations
Java Collaborative Filtering Recommendation Systems Data Processing
Nov 2011 - Apr 2012

R&D Intern

Fredhopper B.V.
Amsterdam, Netherlands
Research and Development internship focusing on recommendation systems and collaborative filtering while contributing to academic research.
  • Automated and industrialized evaluation process of recommendations, creating frameworks still used in production systems
  • Generated new recommendation approaches based on collaborative filtering, contributing to patent applications
Machine Learning Collaborative Filtering Recommendation Systems Research

Key Projects

2024-2025

Conversational Commerce Platform (Single-Agent-with-Tools)

Designed the technical architecture and built the core integration layer for a conversational shopping assistant. Evolved from research prototype to production deployment with a single-agent-with-tools architecture, selected across LLM providers to balance cost, latency, and reasoning quality. Shipped the open-source Dify plugin upstream.
  • Self-initiated from research through PoC to production deployment, providing a narrative and live demo that supported new prospect engagement
  • Evolved architecture from modular intent routing to a single-agent-with-tools pattern with templated prompts and emotional tone adaptation
  • Evaluated LLM providers and reached a 20x lower cost than the initial vendor, with gains in intelligence, tool use, and speed
  • PR merged upstream to dify-official-plugins exposing customer search and merchandising engines as agent tools
Python Java FastAPI MCP OpenAPI LLMs Gemini OpenAI AWS Bedrock Vertex AI Conversational AI Dify Langgraph Kubernetes Microservices
2025

AI-Powered Knowledge Assistants (RAG + Tool-Calling)

Designed and built a dual-purpose AI assistant for customer self-service and support agent enablement. Architected the knowledge processing pipeline to crawl, transform, and embed documentation and anonymized historical ticket data into a searchable vector knowledge base with LLM-powered conversational interface and tool-calling capabilities. Built the evaluation harness as its own workstream before shipping the feature.
  • Targeted the largest addressable support category (~18% of all ticket volume), reducing resolution friction for common how-to questions
  • Internal trial validated ~80% documentation coverage for real customer questions
  • Designed for measurable ticket deflection with a 30% reduction target, directly reducing average resolution times of 20+ days
  • Processed and embedded ~900 knowledge base pages and anonymized customer tickets into the retrieval pipeline
Python Generative AI LLMs RAG Vertex AI FastAPI MCP Vector Search Semantic Search Conversational AI Evaluation Metrics
2025-2026

Hybrid Search (BM25 + BGE-M3) and Agentic Merchandiser Foundation

Shipped a hybrid search system combining BM25 lexical retrieval with BGE-M3 dense retrieval for the search platform serving 200+ enterprise retailers. Laid the foundation for an agentic merchandiser where LLMs plan, query, refine, and reason over the search and merchandising surface via tool calls.
  • Hot-swap rollout to enterprise retailers with zero changes to upstream systems
  • Established the tool-calling surface for an agentic merchandiser to plan, query, refine, and reason over the catalogue
Python Java BGE-M3 BM25 Vector Search Hybrid Search Elasticsearch LLMs Tool Calling Agentic Systems
2020-2023

AI-Powered Semantic Search Platform

Pioneered AI-powered semantic search across two product lines: a standalone hybrid search engine combining vector and traditional search, and an AI Search plugin for the existing e-commerce platform using the same embedding technology for vector-based retrieval. Led technical architecture, technology transfer from an acquired AI company, and scaling to enterprise catalogues.
  • Adopted by enterprise retailers across fashion, sports, grocery, and DIY verticals, supporting 40+ languages
  • Led vector search scaling investigation across 4 backends, identifying the cost-viable architecture for enterprise-scale catalogues
  • Architected dual delivery model: standalone hybrid search engine and AI Search plugin using shared embedding technology
  • Handled 100x traffic spikes through autoscaling architecture validated during production incidents
Python Kotlin Neural Networks Deep Learning Embedding Models Vector Search Semantic Search Information Retrieval Elasticsearch OpenSearch GKE gRPC Distributed Systems
2016-2018

Adaptive Personalization Engine (PoC to Production)

Created the initial proof of concept and led the evolution from research prototype to production platform across 4 major releases. Designed a real-time personalization system that tracked user interactions, built behavioral profiles, and delivered personalized product recommendations and search re-ranking for e-commerce retailers.
  • Created the original proof of concept and evolved it to production across 4 major releases over 2.5 years
  • Built microservices architecture with 6 core components processing real-time user activity streams at 200+ events/second
  • Maintained search response time impact under 50ms average while delivering personalized recommendations
Java Python Apache Storm Apache Kafka Kubernetes Docker AWS DynamoDB Elasticsearch Collaborative Filtering A/B Testing Microservices Snowplow Analytics Real-time Inference

Academic Background

2013 - 2015

Master's in Computer Science (AI Specialization)

Vrije Universiteit Amsterdam (VU Amsterdam)
Amsterdam, Netherlands
Curriculum: Specialized in Artificial Intelligence, Machine Learning, recommendation systems, and information retrieval.
Thesis: Developed and evaluated a hybrid recommender system using matrix factorization with alternating least squares (ALS) to assess the impact of integrating multiple data types on e-commerce recommendation accuracy. Comparative analysis across four datasets using R-Precision, nDCG, MAP, AUC metrics, demonstrating up to 6% AUC improvement over baseline collaborative filtering.
2005 - 2010

B.S. in Systems Engineering

Universidad EAFIT
Medellín, Colombia
Curriculum: Software engineering, statistical methods, parallel computing, data structures.
Thesis: Implemented and optimized parallel AES encryption algorithms on multi-core CPUs and GPUs, achieving up to 19x acceleration with CUDA.

Certifications

Neural Networks and Deep Learning
Coursera (deeplearning.ai), Sep 2017
Improving Deep Neural Networks: Hyperparameter Tuning, Regularization and Optimization
Coursera (deeplearning.ai), Sep 2017
Machine Learning
Coursera (Stanford), Oct 2012
Effective Programming in Scala
École Polytechnique Fédérale de Lausanne, Feb 2024

Publications

Parallelizing AES on Multicores and GPUs

Julian Ortega, Christian Trefftz, Helmuth Trefftz
Parallelized AES block cipher on multi-core microprocessors and GPUs using OpenMP and CUDA, demonstrating GPU speedups up to 19x for encryption-specific operations.
View Publication

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