CV

Apr 2025 – Present · Alcobendas, Madrid, Spain

• Built and run the bank-payment reconciliation service: it identifies the payer from free-text bank descriptions using document and invoice extraction plus fuzzy matching, and matches ~4,200 payments a month to their open invoice at 98.5% precision, with measured recall and an audit trail. Also reconciles the direct-debit batches, flagging what went uncollected.
• Lead the Python/SQL codebase the billing-and-collections team runs daily as its top contributor with 2,000+ commits: refactored 120+ inherited analyst notebooks into an installable package of ~13k lines, with the read layer separated from business logic, SQL externalised and Ruff plus pre-commit hooks on every change.
• Took the reporting pipeline from no tests to 48 test modules: a record/replay module that replays a real run with no database or file server, an in-house snapshot-testing library, and validation gates that fail the run on any anomaly, with no warning level.
• Built and own the datamart and ETL over hundreds of thousands of monthly invoices that feeds the team's reporting, and the integration layer that unifies data access and customer identity across two billing platforms, which kept reporting and automations running through a platform migration and the onboarding of acquired operators.
• Cut the reporting pipeline runtime by 3.6x and RAM usage by 70% with SQL rewrites, vectorised pandas and Parquet with predicate pushdown. Built the content-addressable store that holds the billing history, with the persistent store separated from the working area and atomic writes.

May 2023 – Mar 2025 · ~2 years · Colmenar Viejo, Madrid, Spain

• Built pack-print, a React tool that generates labels and delivery notes, replacing a manual spreadsheet process at a B2B distributor of power relays to Spain's national grid operator. Also automated their invoicing, payments and order fulfilment.

Apr 2022 – Jul 2022 · 4 months · Remote

• Set up the AWS infrastructure (EC2, S3) serving Grafana dashboards over IoT air-quality sensor data from REST APIs.

Software development, algorithms and data structures, databases, networking, Unix and cloud fundamentals.