Leonardo Siusystems + backend
2024 — Present

Experience

A timeline of technical leadership, full-stack product engineering, applied AI/ML, and student initiatives.

Professional & Industry

Backend and AI Systems Engineer

Human Proximity
Aug 2025 — PresentIrvine, CA

Working on backend systems and AI-powered services for a mobile-first proximity and matchmaking platform, focused on scalable inference, real-time interactions, and production-ready AI infrastructure.

  • Architected backend services that power AI-driven matching, prioritizing low-latency inference while keeping the system flexible for rapid product iteration.
  • Designed AI service layers around embedding-based retrieval, focusing on clean interfaces between model inference, vector search, and application logic.
  • Built scalable API infrastructure for mobile clients, handling authentication, async workloads, and real-time data orchestration.
  • Collaborated closely with product and frontend teams to translate ambiguous product ideas into stable backend and AI service abstractions.
Applied AISystems EngineeringEarly-Stage R&D

Meta AI Studio Fellow

Break Through Tech × Meta
Aug 2025 - Dec 2025Remote

AI Studio Fellow focused on applied NLP systems, model evaluation, and deployment-oriented ML workflows.

  • Built an end-to-end NLP system to analyze and surface bias in large-scale online discourse, spanning data preprocessing, model fine-tuning, evaluation, and user-facing interaction.
  • Led the ML pipeline design for preprocessing and labeling ~28k Reddit comments, emphasizing data quality, bias representation, and reproducibility across experiments.
  • Fine-tuned transformer-based language models (BERT) for bias detection, iterating on loss functions, class imbalance strategies, and evaluation metrics to understand model behavior beyond accuracy.
  • Developed a full-stack interface that allows users to interact with the deployed model, translating abstract ML outputs into interpretable, real-world feedback.
Applied AINLPML SystemsModel EvaluationFull-Stack Engineering
NLP Bias Detection RepoLive Demo

AI/ML Fellow

Break Through Tech × Cornell Tech
May 2025 - PresentRemote

AI/ML Fellow in a selective, industry-aligned program focused on applied machine learning, responsible AI, and professional engineering practice.

  • Selected into a competitive national fellowship focused on preparing engineers to apply machine learning in real-world, industry contexts.
  • Developed a strong foundation in end-to-end ML workflows, including data preprocessing, model training, evaluation, and deployment considerations.
  • Collaborated with peers across universities on applied ML projects, emphasizing reproducibility, ethical considerations, and clear technical communication.
  • Participated in technical workshops, industry talks, and mentorship sessions that emphasized translating ML research into production-ready systems.
Applied MLNLPComputer VisionData-Centric MLIndustry Fellowship

Backend Engineer Intern

Rooh | Berkeley SkyDeck Pad-13 Incubator
Aug 2025 — Dec 2025Berkeley, CA

Worked on core backend and AI infrastructure for an early-stage startup building tools to help users gain confidence in their own voice through guided, conversational practice.

  • Co-developed RoohPlay, a core MVP feature enabling users to practice custom scenarios (interviews, standups, meetings) through a real-time conversational AI experience.
  • Designed and implemented a custom end-to-end audio pipeline (VAD → STT → LLM → TTS), built from scratch to support low-latency, multi-turn voice interactions.
  • Engineered backend APIs to orchestrate speech processing, LLM inference, and session state, prioritizing responsiveness and reliability under real-time constraints.
  • Built AI-driven evaluation workflows that analyze completed sessions across multiple dimensions, translating raw interaction data into actionable feedback for users.
  • Collaborated in a small, fast-moving intern cohort (2 engineers), working closely with founders to scope, build, and ship production features end-to-end.
Next.jsReactTypeScriptSupabaseGCPSpeech-to-TextText-to-SpeechLLM APIs

Full-Stack Software Engineer Intern

Vulcan Engineering Solutions
Feb 2025 - May 2025Laguna Niguel, CA

Engineering agentic, AI-powered workspaces. Think less busywork, more brainpower, and a lot of learning on the fly.

  • Migrated backend infrastructure from a monolithic Next.js API to a dedicated NestJS service, improving reliability and production stability.
  • Implemented backend APIs and state management with TanStack Query and Redux to support real-time job workflows and bid lifecycle transitions.
  • Diagnosed and resolved production bugs and environment issues, contributing to smoother deployments and reduced runtime errors.
Next.jsReactTypeScriptNestJSPostgreSQLRedisAzure App Services

Frontend Developer (Contract)

Vulcan Engineering Solutions
Oct 2024 - Feb 2025Laguna Niguel, CA

Contributed to building and stabilizing an AI-powered engineering marketplace, progressing from frontend MVP development to full-stack infrastructure ownership.

  • Built the initial MVP frontend from scratch, including a job posting marketplace, engineer workspaces, and a bid-based matching workflow between clients and engineers.
  • Designed and implemented job workspaces with file viewing, job context, location metadata, and threaded collaboration features.
  • Delivered a performant, production-ready UI with strong UX fundamentals, earning 95+ Lighthouse scores across core pages.
Next.jsReactTypeScriptTailwind CSSSupabaseStripeSendGrid

Student Software Developer (Part-Time)

Office of Information Technology, UC Irvine
Apr 2024 - PresentIrvine, CA

Building and shipping student and advisor-facing systems used at scale across the university.

  • Developed and maintained core features for UCI Spark and ScoreShare, supporting 10k+ active users across students, advisors, and administrators.
  • Designed backend workflows to reduce unnecessary data load, introducing scheduled batch processing and background services in .NET/C# to replace costly real-time queries.
  • Implemented automated data ingestion pipelines from sources like Canvas Data API and BigQuery, replacing manual data entry and improving reliability of downstream features.
  • Worked within a cross-functional Agile team to ship and iterate on features using .NET, SQL Server, Blazor, React, and AWS, balancing delivery speed with system stability.
  • Helped improve deployment confidence by maintaining CI/CD pipelines and supporting production debugging and QA workflows.
.NETC#SQL ServerBlazorReactAWSCI/CDAgile
Next: Student Leadership

Student Leadership & Organizations

Software Lead

CareTech @ UCI
Oct 2025 - Present

Student health-tech initiative building AI-powered tools for brain health and nutrition.

  • Co-leading a 10+ person engineering team, defining technical direction and breaking down product requirements into shippable milestones.
  • Architecting an AI-assisted food logging system combining real-time object detection, user feedback loops, and personalized health insights.
  • Balancing product vision with execution to guide technical decisions across frontend UX, backend services, and applied ML tradeoffs.
Technical LeadershipApplied AIHealth Tech

Full-Stack Developer

Commit the Change @ UCI (CTC)
Oct 2025 - Present

Empowering nonprofits with reliable, maintainable software built by UCI designers and developers.

  • Collaborating with 11+ engineers and 4+ designers to deliver a full-stack platform for a nonprofit legal services organization.
  • Translating design mockups into production features while designing relational schemas and backend APIs to support complex workflows.
  • Working in an Agile, sprint-based environment, contributing across frontend, backend, and database layers as the product evolves.
Full-Stack DevelopmentAgileNonprofit

Web Developer

UCI CanSat
Jul 2024 - Present

Interdisciplinary aerospace team competing in national rocketry competitions.

  • Rebuilt the team’s public website to improve information flow, performance, and visual storytelling.
  • Integrated the LinkedIn Community Management API to surface live team updates, significantly increasing site engagement.
  • Introducing Sanity CMS to decouple content from code, enabling non-developers to manage updates independently.
FrontendCMSAPI Integration

Marketing Organizer

VenusHacks
Nov 2024 - May 2025

Student-run hackathon focused on inclusion and community building.

  • Collaborated with design team to build and maintain the hackathon website during active application cycles.
  • Helped drive participation through visual storytelling, capturing event and organizer photography used across web and social platforms.
  • Supported marketing and logistics efforts that shaped the overall participant experience.
FrontendCMSPhotography
Back: Professional & Industry