Aries L.-Senior AI / LLM Backend Engineer | Java Spring Boot | Python | RAG | Recommendation Systems | LangChain | LlamaIndex
Check rate
Experience
Senior AI / LLM Backend Engineer
Diffbot
- Architected production RAG enrichment services for crawled web content using Python, FastAPI, LangChain, LlamaIndex, embeddings, vector search, PostgreSQL, and Redis, reducing manual analyst review by 35% while making extracted knowledge reusable across downstream AI workflows.
- Designed metadata-aware chunking, hybrid retrieval, reranking, source-grounding, and structured JSON output validation for organization, product, article, and discussion entities, improving extraction consistency by 18% across selected high-volume datasets.
- Built async LLM processing workers with retry-safe execution, caching, prompt versioning, batch scheduling, and token-efficient context preparation, reducing average LLM cost per enriched record by 26% and improving p95 enrichment latency by 22%.
- Developed evaluation workflows with golden datasets, retrieval-quality checks, human review feedback, and prompt regression testing, catching 90%+ of high-risk prompt or retrieval regressions before release.
- Evaluated open-source model and fine-tuning strategies, including LoRA/QLoRA feasibility for classification and entity extraction workloads, comparing accuracy, latency, infrastructure cost, and operational risk before production adoption.
- Partnered with ML, backend, and data teams to improve schema validation, structured logging, failure alerts, enrichment dashboards, and architecture review discipline across large-scale crawl and AI enrichment pipelines.
Senior Backend & AI Systems Engineer
Iflexion
- Rebuilt ecommerce search, catalog discovery, and recommendation backend modules using Node.js, TypeScript, Python, PostgreSQL, Redis, and React, increasing product findability by 17% across high-traffic catalog and customer journey workflows.
- Optimized search ranking rules, catalog filters, cache design, and API response structure, reducing zero-result searches by 21% and cutting average response time by 25% in frequently used portal modules.
- Integrated NLP-assisted chatbot and recommendation flows into ecommerce applications, helping customers reach relevant products faster and deflecting 28% of repetitive product inquiry interactions from support channels.
- Improved backend service boundaries, query patterns, and repeated database access paths, lowering database load during catalog-heavy traffic while keeping recommendation and discovery flows responsive under peak usage.
- Introduced stronger API contracts, release checks, debugging standards, and cross-team handoff practices, reducing late-cycle rework and improving release confidence for client-facing ecommerce systems.
- Mentored 3 engineers through code reviews, production debugging, design reviews, and release planning, raising backend ownership and improving consistency across shared service modules.
Java Backend Engineer
Software Mind
- Developed Java Spring Boot microservices for finance, telecom, and enterprise platforms using REST APIs, PostgreSQL, Redis, SQL optimization, messaging workflows, and event-driven architecture.
- Designed event-driven synchronization services across internal systems, reducing manual data handoff by 40% and improving operational data freshness for reporting, customer service, and back-office teams.
- Hardened authentication, authorization, audit logging, RBAC, retry handling, and failure recovery patterns across sensitive workflows, reducing repeat production issues by 38% in business-critical modules.
- Tuned SQL queries, indexes, background jobs, and reporting pipelines for data-heavy applications, reducing slow report generation from several minutes to under 20 seconds in key workflows.
- Improved microservice reliability through structured logging, failure alerts, idempotent processing patterns, and clearer service ownership, making production incidents easier to diagnose and recover.
- Collaborated with architects, DevOps engineers, QA teams, and overseas stakeholders across time zones to deliver backend features with stronger release predictability and fewer post-release defects.
Full Stack Java Developer
Exist Software Labs
- Modernized Java-based retail and POS modules for inventory, sales, branch operations, cashier workflows, reporting, and financial transactions across business-critical retail systems.
- Delivered full-stack features for product management, stock movement, transaction processing, and sales reporting, reducing manual reconciliation effort by 30% for operations teams.
- Refactored legacy Java and SQL modules into cleaner service, repository, and validation layers, reducing post-release fixes by 24% in frequently updated retail components.
- Built admin dashboards and reporting interfaces using JavaScript, HTML, CSS, SQL, and REST integrations, helping managers filter, export, and review branch-level performance data more efficiently.
Architectural Designer
SP Moderna
- Prepared architectural design concepts, floor plans, elevations, sections, and presentation drawings for residential and commercial projects.
- Created detailed 2D drawings using AutoCAD and supported 3D modeling and visualization for client presentations.
- Assisted in space planning, layout development, material selection, and design revisions based on client and project requirements.
- Coordinated with architects, engineers, and construction teams to ensure design drawings were clear, accurate, and buildable.
- Reviewed project measurements, site conditions, and design details to support smooth project execution.
- Helped improve drawing quality and project documentation by maintaining organized files, updated revisions, and consistent drafting standards.
Industry experience
See where this freelancer has spent most of their professional time.
Experienced in Retail, Information Technology, Construction, Real Estate, Banking and Finance, and Telecommunication.
Business area experience
See which departments and functions this freelancer has contributed to most.
Experienced in Information Technology, Product Development, Research and Development, and Operations.
Summary
Senior AI / LLM Backend Engineer with 10+ years of experience building production backend systems, recommendation workflows, semantic retrieval platforms, and LLM-powered automation services. Combines deep Java Spring Boot and Python backend experience with hands-on architecture of RAG pipelines, vector search, prompt orchestration, evaluation frameworks, and high-availability microservices. Strong record of improving retrieval quality, reducing manual review, lowering latency and LLM cost, and turning uncertain AI outputs into reliable business workflows through validation, observability, and reproducible engineering practices.
Skills
Java
Spring Boot
Python
Fastapi
Flask
Node.Js
Nest.Js
Typescript
Rest Apis
Graphql
Microservices
Async Workers
Background Jobs
Api Gateways
Oauth2
Jwt
Rbac
Rate Limiting
Webhook Architecture
Langchain
Llamaindex
Rag
Embeddings
Semantic Search
Vector Retrieval
Prompt Orchestration
Prompt Versioning
Structured Outputs
Json Schema Validation
Function Calling
Source Grounding
Hallucination Reduction
Llm Evaluation
Numpy
Pandas
Scipy
Scikit-Learn
Pytorch
Hugging Face Transformers
Feature Engineering
Model Evaluation
Text Classification
Clustering
Similarity Scoring
Ranking Models
Model Benchmarking
Offline Evaluation Datasets
Product Discovery
Ranking Rules
Hybrid Search
Metadata Filtering
Top-K Retrieval
Reranking
Semantic Retrieval
Catalog Search
Personalization Workflows
Entity Matching
Deduplication
Relevance Tuning
Postgresql
Pgvector
Mongodb
Mysql
Redis
Elasticsearch
Opensearch
Pinecone
Weaviate
Milvus
Sql Optimization
Indexing
Caching
Data Modeling
Etl Workflows
Data Quality Checks
Kafka
Rabbitmq
Event-Driven Architecture
Retry Handling
Dlq Patterns
Idempotency
Async Processing
Distributed Tracing
High-Availability Service Design
Golden Datasets
Prompt Regression Testing
Retrieval-Quality Checks
Token Usage Optimization
Model Selection
Openai
Azure Openai
Anthropic Claude
Llama 3
Mistral
Lora/Quora Evaluation
Aws
Azure
Gcp
Docker
Kubernetes
Terraform
Github Actions
Gitlab Ci/Cd
Ci/Cd Pipelines
Cloudwatch
Application Insights
Deployment Automation
Monitoring
Alerting
Structured Logging
Performance Tuning
P95 Latency Reduction
Failure Alerts
Incident Debugging
Production Dashboards
Service Health Metrics
Release Validation
React
Next.Js
Typescript
Javascript
Dashboard Interfaces
Admin Portals
Api Integration
Data-Heavy Ui Workflows
Languages
Education
Pampanga State University
B.S. in Architecture · Architecture · Pampanga, Philippines
Certifications & licenses
Microsoft Certified: Azure AI Engineer Associate
AWS Certified AI Practitioner
MongoDB Associate Developer
Statistics
Experience
Expertise
Qualifications
Frequently asked questions
Have questions? Find more information here.
Aries is based in Minalin, Philippines and can operate in on-site, hybrid, and remote work models.
Aries speaks the following languages: Tagalog (Native), English (Advanced).
Aries has at least 15 years of experience. During this time, Aries has worked in at least 5 different roles and for 5 different companies. The average length of individual experience is 3 years. Note that Aries may not have shared all experience and actually has more experience.
Based on recent experience, Aries would be well-suited for roles such as: Senior AI / LLM Backend Engineer, Senior Backend & AI Systems Engineer, Java Backend Engineer.
Aries's most recent position is Senior AI / LLM Backend Engineer at Diffbot.
In recent years, Aries has worked for Diffbot and Iflexion.
Aries is most experienced in industries like Retail, Information Technology, and Construction. Aries also has some experience in Real Estate, Banking and Finance, and Telecommunication.
Aries is most experienced in business areas like Information Technology, Product Development, and Research and Development. Aries also has some experience in Operations.
Aries has recently worked in industries like Information Technology and Retail.
Aries has recently worked in business areas like Information Technology, Product Development, and Research and Development.
Aries holds a Bachelor in Architecture from Pampanga State University.
Aries has 3 certificates. These include: Microsoft Certified: Azure AI Engineer Associate, AWS Certified AI Practitioner, and MongoDB Associate Developer.
Aries is immediately available full-time for suitable projects.
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Average rates for similar positions
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The average daily rate is the mean of all daily rates from recent contracts of comparable freelancers on our platform.
The median daily rate is the middle value of all daily rates — half of comparable freelancers charge less, half charge more. Unlike the average, it is barely affected by outliers.
Calculated based on our freelancers’ daily rates as of 6 Nov 2026. Actual rates may vary depending on seniority level, experience, skill specialization, project complexity, and engagement length.
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