José Ignacio Feliú Fernández
Software engineer. Building products across the full stack — from on-device ML and embedded firmware to cloud backends and web applications.
Now
Building Atribu — an attribution platform that helps performance agencies understand which ads actually drive revenue. Connecting data from Meta Ads, GoHighLevel, Stripe, and MercadoPago into a single source of truth.
Thinking about multi-touch attribution models, real-time data pipelines, and how to make complex analytics feel simple for agency teams that don’t have a data engineer on staff.
Updated March 2026
Atribu
Attribution platform for performance agencies — built from scratch in one month
Performance agencies run ads across multiple platforms and track conversions through CRMs, payment processors, and landing pages. The problem: there’s no unified view of what’s actually working. Agencies rely on platform-reported metrics that inflate results, or they build fragile spreadsheets that break every month.
Atribu connects the full pipeline — ad spend from Meta Ads and Google Ads, leads from GoHighLevel, payments from Stripe, MercadoPago, and Shopify, organic traffic from Google Search Console, and brand context from Notion — eight integrations with OAuth flows, webhook listeners, and periodic sync.
Attribution Engine
Eight attribution models — first-touch, last-touch, last non-direct, linear, position-based, time decay, 50/50 split, and custom weighted — all computed at query time via Postgres RPCs. No pre-stored credits; switch models instantly without reprocessing. Identity stitching links anonymous visitors to known customers across devices. Synthetic touches are created for off-site conversions (e.g., GHL leads arriving via Meta) by matching lead metadata against prior session history.
Tracking SDK
A standalone JavaScript tracker distributed as an IIFE snippet and npm package. 30+ auto-capture modules — page views, form submissions, Stripe checkouts, Shopify purchases, GHL funnel forms, outbound links, video engagement, scroll depth, Web Vitals, and custom events. Events persist to localStorage and batch-send with exponential backoff. Bot filtering, AI agent detection, GDPR consent handling, and SPA navigation tracking out of the box.
Ads Explorer
Scrapes live competitor ads from Meta and TikTok — creatives, headlines, body copy, media. ML-powered scoring ranks ads by engagement potential. Extracts keyframes and audio from video ads. Feeds directly into the Ads Lab for variation generation.
Ads Lab
Multi-agent system for ad creation, built on Vercel AI’s ToolLoopAgent. Specialized agents — coordinator, research, psychology, copywriting, video scripting, compliance, and a critic that triggers retry loops for quality — orchestrated in a pipeline that produces ad copy, video scripts, and full creative briefs informed by competitor data from the Explorer and brand context from Notion.
Analytics & Reporting
Real-time dashboards with dual-period KPIs, funnel analysis, channel breakdowns, customer journey visualization, and AI-generated insights. Scheduled reports via email, PDF exports, and shareable public links. A public API with 25+ endpoints, rate limiting, and scoped API keys.
SoyMomo
Children’s technology — smartwatches, tablets, baby monitors
SoyMomo builds connected devices for children’s safety. I worked across nearly every product line for five years — smartwatches, tablets, baby monitors, and their cloud backends. Started as an intern doing AOSP research, grew into owning full product verticals.
Key projects: created the Space 3 smartwatch launcher and 20+ watch applications; designed a multi-stage NLP pipeline for detecting cyberbullying and grooming on tablets (my university thesis, deployed in production); built the Baby Monitor Pro 3.0 from ESP32 firmware and custom PCB to WebRTC streaming app; deployed a Valhalla server for GPS route matching with custom clustering algorithms; created the HeyMomo voice assistant; and built CI/CD, MVNO integration, and tablet system infrastructure.
Space 3 Smartwatch Platform
Created the initial launcher and led development across 20+ applications for SoyMomo’s flagship children’s smartwatch. Built the chat app, phone dialer, phonebook, camera, gallery, keyboard, settings, step counter, reminders, friends, app store, and authentication manager — all running on constrained Android hardware with custom system-level behaviors.
Developed and integrated an on-device keyword spotting model using MFCC feature extraction, a CNN classifier, and SVDF layers, enabling streaming audio intelligence on the watch while meeting strict latency and power constraints. This work spearheaded the launch of a smartwatch generation that surpassed previous models and boosted SIM-card adoption.
Dangerous Content Detection — NLP Pipeline
University thesis project, deployed in production
Designed and implemented a multi-stage NLP moderation pipeline for SoyMomo’s Android tablets to detect cyberbullying, grooming, and explicit content in near real time. The system works in layers:
- OCR ingestion — replaced accessibility-based text extraction with screenshot-based OCR using Google ML Kit. Periodic capture, deduplication, local persistence, and cleanup workers.
- Dictionary models — weighted scoring for mood, cyberbullying, and grooming terms with regex patterns, slang expansion, and bilingual coverage.
- On-device classifier — evaluated RoBERTa, DeBERTa, BETO, and RoBERTuito; selected XLM-RoBERTa for multilingual performance. Fine-tuned on 20,000 curated examples, converted to ONNX, and quantized — reducing memory by 40% and increasing inference speed by 30%.
- Rust/JNI tokenizer — integrated Hugging Face tokenizers in Rust via JNI for performance-sensitive inference on Android.
- Cloud verification — batch processing with GPT-4o using JSONL batches and scheduled backend jobs for second-stage validation.
- Parent-facing alerts — real-time notifications with labels, screenshots, and detailed detection views.
Experiment tracking with MLflow. Model versioning with DVC. The full architecture and evaluation are documented in my university thesis.
Baby Monitor Pro 3.0
Started and created a next-generation baby monitor from scratch. Designed around an ESP32 with OV2640 camera on a custom PCB, all firmware written in C using Espressif’s IDF framework. Real-time audio and video streaming over WebRTC with a privacy-first architecture — no cloud relay, direct peer-to-peer connections between the monitor and the parent’s phone.
Built the companion Android application with BLE provisioning and live stream playback. Explored Wi-Fi HaLow (802.11ah) for extended range on sub-1GHz bands using Morse Micro MM8108 modules, including custom kernel module work on Android 14 with UNISOC T616 hardware.
Also built the cloud backend for audio/video IoT streaming using MQTT, RTMP, NGINX, and AWS, plus infant pose detection and baby cry classification models for smart alerting.
Location History & Route Matching
Rebuilt the location history feature for SoyMomo’s smartwatches, turning noisy GPS traces from children’s devices into clean, meaningful routes. Deployed a self-hosted Valhalla server for map-matching and implemented multiple clustering strategies to find the best route that matches the actual path the child took during the day.
Implemented and evaluated ST-DBSCAN (spatio-temporal density clustering), adaptive clustering that adjusts parameters based on GPS data density, stop-detection algorithms for identifying stationary periods, time-windowed clustering, and trajectory simplification. All with weighted centroid calculations based on GPS accuracy. Built a Next.js dashboard for visualizing and comparing experiments across algorithms.
HeyMomo — Voice & AI Assistant
Created a voice assistant for SoyMomo’s smart devices using GCP speech-to-text and text-to-speech, enhanced with word2vec, topic modeling, and clustering for better intent understanding. Later evolved into an LLM-powered conversational system backed by Supabase for persistent memory — the assistant remembers facts about each child (favorite colors, foods, school subjects) and can manage contacts, send messages, and initiate calls.
Also developed and published an Android audio recording library on Maven, standardizing device-side audio capture across SoyMomo products and reducing development time for audio features.
Tablet Platform & System Engineering
Built and maintained core Android functionality for SoyMomo’s tablet platform, including system-level services, screenshot and monitoring infrastructure, foreground services, overlay management, MediaProjection, and OEM/system-app deployment. Refactored the tablet application update system with Cloudflare, reducing data transfer costs and improving update efficiency across the production fleet.
Also shipped an image detection system using YOLO for identifying inappropriate visual content on the tablets.
SIM Subscriptions, CI/CD & AOSP
Led the app-side implementation of SoyMomo’s SIM subscription capability, including MVNO investigation, recurring-revenue feature development, and integration with backend systems and SIM providers. Created CI/CD pipelines for most of SoyMomo’s Android applications, improving deployment speed and reliability. Earlier on, researched and implemented a basic operating system based on AOSP and improved the architecture of the ad-blocking service.
Work
Atribu
· Technical Co-founder · 2026–presentBuilding an attribution platform for performance agencies from scratch. Full-stack — React/Next.js frontend, integrations with Meta Ads, GoHighLevel, Stripe, MercadoPago, and Notion. Leading all product and engineering as technical co-founder.
Connect Marketing
· CEO & Co-founder · 2024–presentCo-founded a fundraising agency serving foundations as primary clients. Locked multi-year contracts, built the business model and client presentations, and manage weekly client relationships. On the technical side, automated the entire operation — built a Next.js admin dashboard for commissions, payments, accounting, and tax compliance (SII); a Kotlin Multiplatform mobile app for field salespeople to scan IDs and upload receipts; an OCR pipeline for receipt processing at scale; and financial modeling tools for campaign projections. Reached ~$1M in gross revenue in its first full year. Currently scaled back (operations automated) while focused on Atribu.
SoyMomo
· Software Engineer · 2021–2026Five years across smartwatches, tablets, baby monitors, and cloud services for a children’s technology company. Shipped 20+ Android applications for the Space 3 watch, built an NLP safety pipeline for content moderation, created a baby monitor from custom hardware to companion app, and led location history, voice assistant, and infrastructure projects. Started as an intern doing AOSP research, grew into owning full product verticals.
Education
Pontificia Universidad Católica de Chile
· 2019–2024Ingeniero Civil en Computación (Computer Engineering). Major in Software Engineering, minor in Data Science & Analytics.
Thesis: NLP pipeline for dangerous content detection on children’s tablets — deployed in production at SoyMomo.
Teaching Assistant
Guided student teams through their capstone projects, providing weekly mentorship on progress and scope. Also taught a module on software testing best practices — static analysis, monitoring, code review, and CI/CD.
Grading assistant for two semesters. Evaluated assignments and exams in combinatorics, graph theory, and formal logic.
How I Build
Opinionated choices, picked through trial and error. I value tools that let me move fast without fighting the framework.
Frontend
React + Next.js + TypeScript. I’ve tried alternatives. I keep coming back. The ecosystem depth, the hiring pool, and the App Router’s server component model make it the pragmatic choice for products that need to ship and iterate fast.
Styling
Tailwind CSS + shadcn/ui. Utility-first is the right abstraction for UI. No naming debates, no specificity wars, no dead CSS. shadcn/ui gives you real components you own — not a dependency that breaks on every major version.
Mobile & Embedded
Native Android (Kotlin), C for firmware, Rust where it counts. After years of system-level Android work on constrained hardware, I default to native over cross-platform. For embedded, ESP-IDF and C give you the control you need. Rust via JNI when you need safe, fast bridging between worlds.
ML on Device
PyTorch for training, ONNX for deployment. Fine-tune in Python, quantize aggressively, run on-device with ONNX Runtime. MLflow for experiment tracking. The model that runs on a kid’s tablet needs to be fast and small — not just accurate.
Payments
Stripe for international, MercadoPago for LATAM. You can’t serve Latin America with Stripe alone. MercadoPago handles local payment methods that Stripe simply doesn’t support.
Integrations
Build the pipeline, not the wrapper. Third-party APIs break, change, and rate-limit. I invest in resilient sync infrastructure — retries, idempotency, real-time webhooks — rather than thin client wrappers that fall apart in production.
AI-Assisted Development
Early adopter, daily user since day one. Started with GitHub Copilot for scaffolding, then ChatGPT the day it launched. Moved to Cursor when it went public, and now run a cross-model workflow between Claude Code and Codex that I’ve refined over the last two months.
My current flow: plan a feature in Claude Code, pass that plan to Codex to refine it, then hand the refined plan to a fresh Claude Code session for implementation — forcing it to rebuild context from scratch with only the plan. After implementation, Codex reviews for edge cases and correctness. I keep iterating between the two until Codex tells me the feature is ready to ship.
I don’t use trending prompt frameworks — I think they’re crutches for people who aren’t technical enough to prompt well on their own. Vanilla Claude Code with its internal planning is good enough if you know what you’re building. The leverage comes from understanding the code deeply and using AI to move through implementation faster, not from outsourcing the thinking.