Leandro Guardia
Verified Expert in Engineering
Artificial Intelligence (AI) Developer
Santa Cruz de la Sierra, Santa Cruz Department, Bolivia
Toptal member since June 17, 2019
Leandro is a senior full-stack software engineer with strong experience designing and delivering scalable, production-grade platforms. He works across the front end, back end, and infrastructure, focusing on clear domain modeling, solid business logic, and maintainable architectures that grow with product complexity. Known for clear communication, ownership, and effective collaboration with cross-functional teams, he applies quality-first practices to improve delivery speed and reliability.
Portfolio
Experience
- Artificial Intelligence (AI) - 9 years
- Web Development - 9 years
- Data Analysis - 5 years
- Ruby on Rails (RoR) - 4 years
- Python 3 - 4 years
- Node.js - 4 years
- React - 2 years
- Next.js - 2 years
Work Experience
Architect & AI Developer
Abby Robinson
- Built a hybrid Gmail backfill system pairing a 12-month async historical scan (Cloud Tasks, checkpointed/resumable) with incremental delta sync on one shared two-pass pipeline.
- Engineered a forward/backward size-projection algorithm estimating a child's current clothing and shoe size from purchase history and age-based growth rates, driving automated restock nudges.
- Shipped an async, Claude-driven email classification and extraction pipeline turning raw Gmail purchase receipts into structured, per-child apparel inventory records.
- Delivered an admin analytics suite giving the client visibility into nudge delivery, engagement, and account health.
- Led Google OAuth production verification, including a third-party CASA security assessment, to certify restricted Gmail and Calendar scopes for live use.
- Designed an architect-client Git contribution workflow with PR/Issue templates and risk-tiered change classification, letting a non-technical client self-deploy safe-zone changes.
Technical Lead
elGenioX
- Defined core values, principles, and architectural standards, enabling a cohesive culture and efficient cross-team collaboration while maintaining system consistency and code quality.
- Migrated a fragmented Shopify-based ecosystem and auxiliary systems into a greenfield, microservices-based marketplace architecture designed for scalability, flexibility, and long-term growth.
- Researched, validated, and implemented a data-driven UI/UX strategy focused on simplicity and accessibility for users transitioning to digital commerce in the Bolivian market.
- Redesigned and decoupled a decentralized and inconsistent information flow into a cohesive, marketplace-centric, and pluggable system architecture.
- Designed and exposed core internal and external APIs (Identity, Catalog, and Sales), and integrated them with existing enterprise systems.
- Established and automated a lean CI/CD pipeline with linting, testing, and static analysis across development, staging, and production environments.
- Architected and delivered intuitive, high-quality user interfaces for end customers, seller onboarding, logistics operations, and administrative users.
- Introduced a shift in team mindset toward using AI as a strategic tool by promoting incremental, human-centered adoption for decision support, design assistance, and automation of repetitive tasks.
AI and Programming Lecturer
Universidad Católica Boliviana
- Delivered undergraduate courses in artificial intelligence and software design, combining theory with hands-on practice to prepare students for real-world challenges.
- Taught AI fundamentals, including search algorithms, machine learning, and neural networks, using Python, Pandas, NumPy, Scikit-Learn, Keras, and Matplotlib.
- Guided students through software design and programming concepts, including object-oriented design, refactoring, unit testing, TDD, recursion, pointers, and dynamic memory management in C++.
- Designed and implemented practical projects and exercises that reinforced theoretical knowledge while developing problem-solving and algorithmic thinking skills.
- Mentored students on applying AI techniques and software engineering best practices to independent projects, ensuring comprehension and professional readiness.
Back-end Software Engineer
Casper
- Designed and maintained back-end wholesale systems supporting drop-ship and bulk orders, including white-glove services, 3PLs, and 3PMs, operating across around 300 warehouses (owned and third-party) and five logistics partners.
- Implemented and optimized box packaging logic for high-volume wholesale orders, significantly reducing shipping inefficiencies and generating meaningful cost savings at scale while ensuring continuity of critical legacy logic.
- Built API clients to generate shipping documents (packing slips and shipping labels).
- Extended and stabilized EDI integrations (850, 855, 856, 860, 810) via a third-party provider, enabling reliable, automated wholesale order processing and eliminating manual operational workflows for high-volume partners.
- Built and maintained API clients for automated shipping document generation (packing slips and shipping labels), removing manual steps from fulfillment workflows and improving operational efficiency across distributed warehouses.
- Acted as a technical reference point for the system, onboarding six new engineers, coordinating work across multiple time zones, enforcing code review standards, and fostering a strong collaborative engineering culture.
- Refactored and strengthened test suites across critical domains, achieving around 80% test coverage in a large, high-traffic codebase, with particular focus on payments, OMS, and asynchronous financial system integrations.
- Diagnosed and resolved a long-standing, high-impact production issue affecting pricing data synchronization, tracing the root cause through extensive log analysis to an unmaintained middleware component and restoring financial data accuracy.
Back-end Software Engineer
Encora
- Took over a flexible back-end codebase that served many web applications with pluggable features and diverse configurations.
- Controlled a robust continuous integration and continuous delivery infrastructure that completes a list of controls and verifications for each environment and client.
- Supervised cron jobs and background processes that performed data parsing routines and validated external dependencies.
- Maintained a chef recipes repository that scheduled email notifications, database backups, and other health checks.
- Refactored production and test code, removed unreachable code, and increased coverage.
Experience
elGenioX Marketplace
https://elgeniox.comLeancontinuo
https://leancontinuo.comPayment Provider Switcher
https://github.com/leanguardia/provider-switcherEducation
Master's Degree in Computer Science
University of Bristol - Bristol, UK
Bachelor of Science (BSc) Degree in Systems Engineering (IT)
Universidad Católica Boliviana "San Pablo" - Cochabamba, Bolivia
Certifications
Data Science Nanodegree
Udacity
Academic Excellence
Universidad Católica Boliviana "San Pablo"
Skills
Libraries/APIs
REST APIs, API Development, React, Node.js, Shopify API, Shopify Storefront API, Claude API, Pydantic, Google Calendar API, Gmail API, Twilio API, SQLAlchemy
Tools
RSpec, Git, Claude Code, Claude, Facebook Pixel, Google Analytics, AI Prompts
Paradigms
Test-driven Development (TDD), Back-end Architecture, ETL, Agile Software Development, Class-based OOP, Object-oriented Programming (OOP), Unit Testing, Scrum, Responsive Web Design (RWD), Search Engine Optimization (SEO), DevOps, Testing, Database Design, Business Intelligence (BI), Prototype-based OOP, Kanban, Functional Testing
Languages
Python 3, Ruby, JavaScript, SQL, TypeScript, Python, TypeScript 5, C++
Frameworks
Ruby on Rails (RoR), Express.js, Bootstrap, Next.js, .NET, NestJS, Jest, Tailwind CSS
Platforms
Google Cloud Platform (GCP), AWS Lambda, Amazon Web Services (AWS), Docker, Kubernetes, Vercel, Blockchain, Shopify, Harness
Storage
PostgreSQL, MongoDB, NoSQL, Redis, Data Pipelines, Database Structure, Data Integration
Other
Web Development, Back-end, Back-end Development, Data Visualization, API Integration, Back-end Admin Systems, Deployment, Front-end, LLM Integration, Third-party APIs, System Architecture, Data Analysis, Agile Software Testing, Machine Learning, Deep Learning, Artificial Intelligence (AI), Software Architecture, Data Migration, Server-side Rendering (SSR), CI/CD Pipelines, Infrastructure, Shell Scripting, Technical Leadership, Architecture, Full-stack Development, Front-end Development, Webhooks, APIs, Solution Architecture, Data Modeling, Data Analytics, Data Engineering, Data Quality, Dashboards, Data Extraction, Reports, Reporting, AI-generated Code, Workflows, Exploratory Data Analysis, GitFlow, Cursor AI, Vibe Coding, Code Review, Communication, Programming, Data Science, Mathematical Logic, Probability Theory, Integration Testing, GitHub Actions, Tailwind UI, Learning, Research, Web3, Smart Contracts, Higher Education, Full-stack, Cloud Architecture, Large Language Models (LLMs), WebSockets, Supabase, Gemini API, AI Agents, AI Integration, Data Structures, Agentic AI, FastAPI, Pingram, SMS, Context Engineering
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