I build and run the systems a business actually depends on — ERP, inventory, accounting and electronic invoicing across four companies in three countries. My work sits where correctness of financial data and continuity of service are not features but the whole job.
Migrated an ERP platform five major versions forward (Odoo 14 → 19) across four legal entities in Chile, Colombia and Peru — end to end, with no data loss and no rollback. Consolidated 41 custom modules into 18, rewrote them against a changed API, and re-certified electronic invoicing for three tax authorities.
Built the monitoring that keeps it honest — around 46 detectors running every day, plus an urgent check every 30 minutes, that reconcile the inventory ledger against the general ledger, track documents rejected by each regulator, and project when authorised invoice numbering ranges will run out. It surfaced a systematic double-counting of inventory cost that had been accumulating unnoticed for over a year.
Built a feature-flag service in Rust from scratch — FlagForge. A pure evaluation engine with no I/O, which is what lets the same crate compile to WebAssembly: the dashboard's rule preview calls the identical function production does, rather than approximating it. Grew A/B experiments on the same foundation — deterministic bucketing doubles as assignment, so counters stay bounded by time rather than traffic. 245 tests, including one that runs a real server on a real socket and compares 300 users evaluated locally against the server's answers.
Built a RAG assistant I can measure — odoo-rag. Hybrid search over the Odoo 19 docs with PostgreSQL + pgvector and local models, plus an evaluation suite on 45 hand-written questions. Recall@5 reached 0.822, and translating the query took Spanish questions from 0.500 to 0.900. The known failures are published with the results.
Organize development so it can be checked — clear layers, tests at several levels, staged releases and production monitoring. Process and architecture of five systems →
| The bugs that survive an ERP upgrade are the quiet ones | The failures that raised errors were fixed in days. The ones that changed behaviour without raising anything lasted weeks — including a single field whose default value silently emptied filters across the system. · 6 min |
| Alert quality beats alert count | Why an alert nobody acts on is a defect rather than a nuisance — including the detector of mine that was confidently wrong, and what it would have cost to act on it. · 5 min |
| Project | ||
|---|---|---|
| odoo-rag | RAG over the Odoo 19 docs with hybrid search and a retrieval and answer evaluation suite | Python pgvector |
| FlagForge | Multi-tenant feature flags: targeted rollouts, reusable segments, A/B experiments, deterministic bucketing, an audit trail — and a dashboard that runs the real evaluation engine | Rust |
| ModoMax | Online store I designed and built end to end, with a shopping assistant, WhatsApp support and AI admin tools (private source) | TypeScript |
| Citofonía | Digital intercom for apartment buildings: concierge calls, door opening, parcels and visits, with the call handled on the server and privacy built into the data (private source) | TypeScript React Native |
| Construye Hoy | Daily site control for construction firms: a field app, a web panel and AI that reads invoices and take-offs for a person to confirm. Built as an independent contractor for a construction firm; in pilot (private source) | TypeScript Supabase |
| SAC Next | Community alarm platform for a municipal programme: remotes and an app sound street sirens, and an operations room follows each alert live. Consulting work, in development | TypeScript MQTT |
| iPhone apps | Norte (native finance and health app) and Maratón Marvel, with real screens and a video | SwiftUI |
| odoo-19-migration-field-notes | Field notes from a production Odoo 14 → 19 upgrade — the failures that raise no error | Open source |
| systematic-trading-showcase | Systematic trading research platform — architecture, risk design and engineering writeup | |
| TBSim Genetic Algorithm | Parallel genetic algorithm (Jenetics) with a computational scalability study — undergraduate thesis | Java |
Earlier: AI News Analyzer · E-commerce REST API · Introduction to Linux · → All repositories
| Backend | Python · Odoo 14–19 · FastAPI · REST APIs · Rust (axum, sqlx, Leptos / WASM) · TypeScript (Hono, Fastify) · Java |
| Frontend & mobile | Next.js · React · React Native / Expo · SwiftUI |
| Data | PostgreSQL · SQL / PL-SQL · migrations · ETL · SAP S/4HANA |
| Infrastructure | Linux · Docker · Git · Odoo.sh · AWS · Azure · HPC |
| Compliance | SII (Chile) · DIAN (Colombia) · SUNAT (Peru) · Active Directory · IAM |
| AI | RAG · pgvector · LLM APIs · tool calling · evaluation · Ollama · LangChain |
IT Manager & ERP Administrator at Toyng — running the ERP for four companies across Chile, Colombia and Peru, and supporting their accounting, warehouse and sales teams.
Open to new opportunities · sallendec@outlook.com · ssebv.github.io