Harm Delva

Data & Software Engineer

Gentbrugge, Belgium
harm.delva@gmail.com · git.sr.ht/~hdelva · linkedin.com/in/harm-delva-193656145

Summary

I am a senior data engineer at Lighthouse in Ghent. I drive the architecture of our integration pipelines that move hotel data into our products and our warehouse. Much of the work revolves around aligning our external partners with our own internal data requirements.

Outside of work I'm a supporter of, and occasional contributor to, the OpenStreetMap Foundation and the Electronic Frontier Foundation. I have various hobby projects ongoing, many of them related to tabletop and digital games.

Work Experience

LighthouseGhent, Belgium
Senior Data EngineerJan 2025 – Present
  • Set the architecture for our hotel data pipelines, and redesigned data acquisition to comply with GDPR. Wrote the scoping and decision documents, and drove the new data domains through months of organization-level review.
  • Rebuilt the pipeline that loads hotel revenue data into the warehouse, modernizing the codebase by moving from pandas and SQLite to DuckDB and BigQuery. Daily cost fell from €350 to €30. The rebuild kept at least two accounts from leaving, together worth $400k in ARR.
  • Led the technical integration of an acquired company into our stack, and replatformed its data onto ours. Cut €3,000 a month by retiring its redundant AWS environment and migrating the data ingestion of roughly 15% of all hotels in the world.
  • Built the service that orchestrates and monitors our pipelines. End-to-end latency fell by 30% for many properties, and the accompanying metrics are the foundation for our monitoring and actionable alerts.
  • Maintained the Terraform repository for our business unit, governing all the GCP projects and underlying infrastructure.
  • Interviewed on 29 hiring panels, 8 of which ended in a hire. Mentored teammates through collaborative troubleshooting and knowledge-sharing sessions.
LighthouseGhent, Belgium
Data EngineerDec 2022 – Jan 2025
  • Became the escalation point for system vendors and hotel groups, including Oracle, Accor, and Wyndham. Aligned fixes with their engineering teams, documented our integrations with over 150 systems, and explained to product and support what the data can and cannot show.
  • Built the gateway that hotel systems send their data to, and defined the reservation, summary, and transaction schemas they build against.
TomTomGhent, Belgium
Software EngineerOct 2021 – Dec 2022
  • Led a project to build a machine learning model that finds missing turn restrictions from GPS traces.
  • Owned data quality for the map data, working with external teams including Microsoft. Ran root-cause analyses to find systematic flaws in how the data was produced.
  • Acted as Scrum master on rotation.
IDLab, Ghent University - imecGhent, Belgium
Doctoral ResearcherMar 2019 – Oct 2021
  • Annotated open datasets and Web APIs to optimize their discoverability and reusability.
  • Designed a multi-modal route planner that runs entirely on static Linked Data Fragments.
  • Designed data models for standardization projects at the European Commission and the Flemish Government.
  • Advised companies on Knowledge Graphs and Open Data.
TrackuityGhent, Belgium
Data ScientistJul 2017 – Feb 2019
  • Improved the recommendation and ad targeting systems behind classifieds sites in Europe and Latin America.
  • Built ETL pipelines for dozens of clients, extracting and cleaning their data as a service.
  • Prototyped two new recommendation systems and evaluated them offline and on live traffic.

Skills

ArchitectureDomain-driven design, ports and adapters, data contracts, event-driven architecture, API design, ADRs and RFCs
Data EngineeringETL/ELT pipeline design, data modeling, query optimization, data quality and validation, data governance, PII handling and GDPR
PlatformGoogle Cloud, Terraform, Kubernetes and GKE, Cloud Run, Pub/Sub, Docker, GitLab CI/CD, AWS Lambda, S3, DynamoDB
ObservabilityStructured logging, Grafana, Cloud Monitoring, alerting, incident response and on-call
DatabasesGoogle Cloud Spanner, Google BigQuery, DuckDB, PostgreSQL, MongoDB, Apache Cassandra
LanguagesPython, SQL, TypeScript, Rust, Zig, Java, Scala
LibrariesFastAPI, Pydantic, Django, Polars, Pandas, Apache Airflow, Atlan
AI & Agentic ToolsClaude Code, Codex, OpenCode, RAG, MCP
Semantic WebKnowledge Graphs, SPARQL, RDF, JSON-LD, NGSI-LD
Natural LanguagesDutch native, English fluent, French basic

Projects

Turn-based tactics gameTypeScript, Deno

Intended to be a midway point between tactical tabletop games and digital auto-battlers. Map generation is built around triangulation and scenarios that introduce specific vertices. Built using Deno (Desktop) to explore modern web technologies for procedural visuals.

git.sr.ht/~hdelva/the-best-game
Personal websiteAstro, TypeScript

A combination of my résumé and a collection of informal AI-free writings. Built using Astro and Paged.js.

git.sr.ht/~hdelva/personal-site
Space station management gameZig

Startopia is one of my favorite childhood games, and I want to blend it with my knowledge of the hotel industry.

git.sr.ht/~hdelva/space

Publications

Selected, most cited first. Full list and citations on Google Scholar

2021 Publishing Base Registries as Linked Data Event Streams — International Conference on Web Engineering

2019 Republishing OpenStreetMap's roads as Linked Routable Tiles — European Semantic Web Conference

2021 Publishing the Marine Regions Gazetteer as a Linked Data Event Stream — International Workshop on Semantics for Biodiversity

2021 Geospatially Partitioning Public Transit Networks for Open Data Publishing — Journal of Web Engineering

2020 Efficient Live Public Transport Data Sharing for Route Planning on the Web — International Conference on Web Engineering

2019 Client-side route planning: preprocessing the OpenStreetMap road network for Routable Tiles — Academic Track, State of the Map 2019

Education

Ghent University2017
Master of Science in Mathematical Computer Science
  • Graduated with distinction
  • Dissertation on data-flow analyses of dynamic programming languages

Program Committees

2020–2022 Program Committee Member — ACM SIGIR Conference on Research and Development in Information Retrieval

2021 Organiser — First workshop on Serendipity in the Smart City

2020 Emergency Reviewer — ACM International Conference on Web Search and Data Mining