Cristhofer Cousiño

Full-Stack / Forward Deployed Engineer · Contract, US fintech

Embedded with two US construction companies' finance and operations teams: I scope work with their accountants and owners and take it to production. Solo until September, then leading two engineers.

• Automated accounts payable from email to approval with OCR and coding rules, raising invoice amount capture from 46% to 71% on 677 invoices
• Built a multi-tenant, mobile-first CRM for construction subcontractors and moved a company into it from Pipedrive
• Moved about 30 dashboards and the company portal onto the fintech's platform, including crew timecards with approvals
• Ported the accounts payable logic into the team's Go service (Echo, GORM, PostgreSQL) and its React front end
• Built receipt and company card reconciliation with document AI and Gemini, Microsoft Entra sign-in across the apps, and daily ERP refreshes from Jonas Premier
• Rebuilt a company's public website and built a tool to review, edit and schedule its newsletter with photos from SharePoint

Software Engineer · Freelance

Custom software for clients in Chile and the United States: backends, internal tools and apps.

• Built an accounting automation portal for a US construction firm: a FastAPI backend with over 200 endpoints behind a Next.js front end, Microsoft Entra ID single sign-on, role-based access and an audit log
• Shipped product and marketing front ends in Next.js and React, plus the REST APIs behind them, with explicit contracts and versioned PostgreSQL migrations
• Ran client work end to end in English: scoping, delivery on a date, and handover that stayed maintainable

Lead Software Engineer · Replicator Platform

Led design and development of a BI and data replication platform for legacy ERPs, with a Spring Boot API of over 150 endpoints.

• Designed a hybrid multi-tenant model in PostgreSQL: one schema per tenant for ERP data, row level security for shared metadata
• Built a replication engine in Java 21 that discovers legacy ERP schemas, runs full or incremental loads, and streams into Postgres in binary format
• Delivered a Next.js front end with a visual query builder, drag-and-drop dashboards and S-curve financial forecasting
• Deployed AWS infrastructure using Secrets Manager for external credentials and OAuth2/OIDC for identity

Tsukimi Reader

Manga reader for Linux, Windows and Android whose Go backend runs Aidoku and Paperback source packages.

Completionist

Go-powered social tracking backend with real-time messaging, challenge systems, and integrations with 6 media providers.

Software Development · Self-taught

Learned independently through documentation, videos, exercises, and personal projects.