
Daniel Demonceau
Verified Expert in Engineering
GIS Engineer and Software Developer
Melbourne, Victoria, Australia
Toptal member since September 22, 2022
A full-stack developer with over 15 years of experience, Daniel specializes in architecting end-to-end geographic information systems (GIS). His expertise spans database design, REST API development, ETL scripting, and back-end optimization, all while crafting intuitive React front ends. He's also a respected voice in the GIS community, sharing insights and solutions on his widely followed technical blog.
Portfolio
Experience
- GIS - 20 years
- Node.js - 10 years
- Python - 10 years
- PL/pgSQL - 10 years
- JavaScript - 10 years
- PostGIS - 10 years
- React - 8 years
- TypeScript - 6 years
Preferred Environment
Visual Studio Code (VS Code), Windows, Linux, Windows Subsystem for Linux (WSL), Cursor AI
The most amazing...
...application I've developed is a severe weather warning app to take preventive measures for the telco's assets and save millions of dollars per year.
Work Experience
Senior Remote Sensing & Geospatial Data Engineer
Carbonleap
- Built a dual-source geospatial ETL pipeline ingesting Sentinel-2 (Google Earth Engine) and PlanetScope (Planet API) imagery into per-field time series; a daily job scans a 7-day window and selects the best image based on the valid-pixel ratio.
- Built per-field vegetation time series with per-pixel, NumPy-vectorized metrics: NDVI, NDRE, MSAVI, NDMI, plus in-field percentile, 14-day rate-of-change regression, and historical percentile/median versus the same day-of-year in prior years.
- Engineered a resumable 10-year backfill that reprocesses every date with valid imagery back to 2015, discovered via Earth Engine catalog queries and parallelized across a 15-thread Celery pool with an LRU file cache and throttled S3 downloads.
- Made the backfill crash-safe with heartbeat tracking, automatic recovery of stuck jobs on worker startup, and S3-to-database reconciliation that re-enqueues any field missing its expected metric outputs.
- Implemented per-pixel cloud and quality masking (Cloud Score+ and Scene Classification for Sentinel-2, UDM2 for Planet), then stored every output as a tiled, compressed Cloud-Optimized GeoTIFF in S3 for downstream dashboards and alerts.
GIS Developer
Three Oaks Carbon, LLC
- Developed a high-performance Python geoprocessing script, leveraging multiprocessing and 85 ArcPy functions to efficiently process geospatial data, capable of handling 100 properties in 2 hours and 40 minutes.
- Led the carbon eligibility project, utilizing ArcGIS Pro for spatial analysis and data management.
- Analyzed, migrated, and processed large-scale imagery datasets for various mapping and analytical purposes.
Founder and Tech Lead
Fluffy Clouds Avenue Pty Ltd
- Developed several full-stack websites to be presented as a portfolio for the company using the Next.js framework as a base.
- Built a battery-powered IoT GPS receiver box with a Raspberry Pi that regularly shares its position and other sensing data like temperature, air pressure, and humidity with a server using the 4G and LP-WAN networks.
- Scripted a Python tool to extract financial information from the Alpha Vantage API and calculate the magic formula score for a set of stocks.
- Prepared technical papers and pitched the startup at events.
Freelance and Blogger
Freelance Clients and Blogger
- Developed several Python scripts to create true-color mosaics from Sentinel-2 satellite granules (images), completed change detection analysis, and performed crop type classifications (supervised and unsupervised).
- Created several maps for a client representing the geothermal potential surrounding the municipality of Plan-les-Ouates in Switzerland.
- Conceived, designed, and implemented the migration plan from an Oracle Spatial database into PostgreSQL and PostGIS.
- Built a real-time web app mapping the Sydney ferries using the NSW public API.
- Explored the DEM, hill shade, and slope analysis capabilities of PostGIS and applied them to the use case of the Brussels capital region.
- Worked on several concept web apps to showcase the capabilities of different GIS tools and methods, such as a holiday picture app, an interactive map showing the indigenous population in Canada, and a web app showing Runtastic outdoor workout routes.
- Created a batch script to extract drone image file metadata and rename the image file with the coordinates of the center of the image.
GIS Developer
Closing Theory Studios, INC.
- Engineered a Python-based spatial clustering tool to automatically group property data into optimized gameplay polygons across the US and Canada.
- Tested and integrated Voronoi diagrams and zip-code layers to enforce strict constraints on polygon size, property counts, and walkability scores.
- Designed an AI-connected feature that dynamically names generated gameplay regions based on the most prominent local landmarks in the area.
Senior Software Engineer
Directed Electronics Australia
- Designed a telematics geofencing solution for our SaaS used by our clients in the road freight industry.
- Maintained the current telematics platform by completing bug fixes in the database, the back end, the API, and the front end.
- Developed new features by making changes in all the layers (vertical slice) and respecting the business case requirements and the deadlines for the product development cycle.
- Migrated data from the legacy database to the new system by extracting data from the source database, preparing JSON messages, and sending POST requests to the new gateway.
Full-stack React Developer
Amini, Corp.
- Built a full-stack GIS dashboard from scratch with Next.js 15, React 19, and TypeScript, exposing rice suitability and NPK recommendations across a 3-level hierarchy of 16 districts and 190 chiefdoms.
- Engineered interactive Leaflet maps rendering 5 soil metrics with drill-down across 3 admin tiers, client-side GeoTIFF overlays via georaster, and confidence shown as color-blind-safe hatch patterns.
- Designed a REST API on Next.js handlers over PostgreSQL with build-time GeoJSON preprocessing and 3-tier caching, cutting repeat map loads to a single in-memory lookup.
- Implemented JWT auth and role-based access control with NextAuth.js, bcrypt (12–14 rounds), 30-day sessions, admin user management, and 48-hour email invitation tokens.
- Delivered PDF reporting capturing live map state with jsPDF across N-page layouts, persisted to a PostgreSQL catalog, and shipped via a 4-stage Docker build and GitHub Actions to Railway.
API Engineer
Pediatric Emergency Standards, Inc.
- Engineered a specialized, high-accuracy geofencing algorithm for indoor hospital environments, successfully overcoming location challenges to ensure reliable tracking for over 200 healthcare workers.
- Evaluated five distinct indoor location-gathering techniques (GPS, 5G, BLE, and Wi-Fi), providing data-backed recommendations that reduced location acquisition error by 15%.
- Delivered a functioning proof of concept (PoC) using Next.js, completing successful field validation across three challenging environments (malls, hospitals, and open fields) to confirm system viability.
ArcGIS Developer
American Homes
- Developed and managed an ArcGIS Online web application, integrating property and zip code data with advanced filtering capabilities.
- Engineered and maintained a Python script for automated synchronization of ArcGIS Online layers with the latest SQL Server data.
- Designed and implemented custom geoprocessing tools to enhance data analysis and visualization within the GIS environment.
GIS Developer and Manager
Vocus Group Ltd
- Led the full-stack GIS team in meeting the business requirements of the GIS infrastructure used by 200+ daily users in the company.
- Conceived, developed, and maintained the entire GIS infrastructure using open source technologies.
- Designed and implemented from scratch a topological database model and migrated the entire asset network data (5+ million records) from two different old systems to the new unique one using Python scripts.
- Wrote most database functions, stored procedures, and views using SQL and PL/pgSQL to keep the whole data model consistent for every CRUD operation.
- Conceived, developed, and maintained the GIS web client of the GIS infrastructure using Node.js, React, Google Maps, OpenLayers, Leaflet, Bootstrap, and Material UI.
- Maintained our mobile app developed in React used by field workers.
- Enhanced the REST API of the GIS infrastructure written in Go.
- Developed a real-time severe weather warning app using the Bureau of Meteorology API and automated the creation of reports listing affected assets for the operation control center team to take preventive measures and save millions in avoiding damage.
- Built a health check app to permanently test the quality and performance of every tier in the GIS infrastructure using JMeter, SchemaSpy, and Python and sent out an alert in case of an outage for quick action.
Senior GIS Engineer
Quadratic SRL
- Wrote Python scripts to import MultiSpectral Sentinel-2 satellite images in batches from their raw formats to PostgreSQL.
- Developed scripts to extract data and process information about crops from Sentinel-2 satellite images using PostGIS, PL/pgSQL, Python, and PyQGIS.
- Analyzed our client's business needs in the agro-industry to improve their harvest logistics and implement the requirements and criteria in the processing scripts.
- Represented the startup at various events about Earth monitoring.
- Prepared and gave training on remote sensing applied to the agro-industry and its concrete applications. Oversaw a series of practical and interactive exercises using Sentinel-2 images, Landsat, and planet data.
Senior GIS Engineer
Oscars
- Provided Oracle Spatial, Oracle GeoRaster, and business analytics consultancy to Groupe ADP in France and Public Service of Wallonia (SPW) in Belgium.
- Oversaw the GIS part for our in-house product designed for airports to help them track any vehicle on the ground in real time to improve the overall logistics on the tarmac.
- Led our team of developers and organized their agendas regarding our in-house developments and external consultancy missions.
- Represented and pitched the startup at various seminars, economic missions, business gatherings, schools, and universities.
GIS Engineer
Esri BeLux
- Developed a pothole detection algorithm using ArcGIS technologies and Python scripting.
- Built additional plugins in JavaScript for the ArcGIS Web AppBuilder.
- Delivered first-line customer support on Esri products, mainly ArcGIS for Desktop, ArcGIS Server, and ArcGIS API for JavaScript for English, French, and German-speaking clients.
- Provided on-site consultancy and coaching on ArcGIS for Desktop, ArcGIS Server, ArcGIS API for JavaScript, and the road network extension (LRS) to our clients in various industries.
- Provided training on the Esri product suite (ArcGIS for Desktop and ArcGIS Server) to a class of clients.
- Presented ArcGIS's newest features at our annual Esri Days event to our clients.
- Attended conferences and seminars and followed technical training on ArcGIS API for JavaScript at Esri Developer Summit in Palm Springs, California, in 2015.
GIS Project Engineer
Hexagon
- Developed a complete and automated test suite in Java for the ERDAS APOLLO product that runs daily and generates reports about the parts that need attention.
- Led and supervised a team of QA engineers for the integration testing of all the Intergraph geospatial server products.
- Customized ERDAS APOLLO according to the client's needs, such as building a custom form tailored to the type of data the client is working with.
- Fine-tuned the ERDAS APOLLO server by configuring the RAM usage, swap space, and file system configuration to have the solution working optimally on the client's infrastructure.
- Provided support, coaching, and consultancy on our range of products and in-house customizations to our clients, mainly on the ERDAS APOLLO product suite.
- Gave 5-day training, at our offices and abroad, on the ERDAS APOLLO product suite to our clients in the EMEA region.
Assistant
ULiege
- Taught fundamental concepts of AutoCAD to students, providing a solid foundation in computer-aided design and drafting.
- Prepared and led the technical fieldwork for topography courses, which included practical work with essential equipment like the Total Station, GPS, and a levelling instrument.
- Corrected and graded student exercises and reports, providing detailed feedback to help them improve their understanding of topographical principles and practices.
Experience
GIS Blog
http://themagiscian.comWebsite for a Land Surveying Company Specialized in Drone Applications
Cumulus Capital Management Website
http://cumuluscapitalmanagement.comPickleball US Region layer Creation
Education
Master's Degree in Economic Sciences and General Management
ULiège - Liège, Belgium
Master's Degree in Geographic Sciences, Geomatics, and Geometrology, Finalization in Land Surveying
ULiège - Liège, Belgium
Certifications
JavaScript Algorithms and Data Structures
freeCodeCamp
Project Management: The Basics for Success
University of California | via Coursera
Successful Negotiation: Essential Strategies and Skills
University of Michigan | via Coursera
ArcGIS Desktop Entry 10.3 (EADE103)
Esri
Skills
Libraries/APIs
ArcGIS, React, Google Maps, Turf.js, GDAL/OGR, GDAL, OpenLayers, Node.js, Google Maps API, Leaflet, NumPy, REST APIs, Kepler.gl, ArcGIS JavaScript API 3, Shapely, jQuery, Google Maps API (GeoJSON), Mapbox API, Mapbox GL, Google Geocoding API, Lodash, PyMongo, React Redux, HERE Maps API, OpenStreetMap API, Pandas, Fiona, Scikit-learn, Matplotlib, Cesium.js, Geofencing API, OpenAI API, Google Maps SDK, Zod, jsPDF
Tools
GIS, Git, Esri, Geocoding, Postman, Sentinel, ArcMap, JSX, Web GIS, Claude Code, GitLab, ERDAS, Oracle Business Intelligence Enterprise Edition 11g (OBIEE), Web AppBuilder for ArcGIS, ArcGIS Collector, Prisma, Apache, Apache Maven, Perforce, IntelliJ IDEA, Atom, Slack, Auth0, PostCSS, GitHub, NPM, Intergraph GeoMedia, Shell, Apache Tomcat, AWS Command Line Interface (CLI), Kubectl, AutoCAD, Autodesk, Cordova Plugins, Capacitor, Docker Hub, Docker Compose, Uvicorn, Pytest, Celery, RabbitMQ
Languages
Python, JavaScript, PL/pgSQL, TypeScript, KML, HTML, CSS, C++, Java, Go, PHP, SQL, XML, GML, YAML, GraphQL, Batch, Bash
Platforms
ArcGIS Online (AGOl), Visual Studio Code (VS Code), Windows, Linux, Oracle, Ubuntu, Vercel, ArcGIS Server, Docker, WordPress, RedH, Mapbox, Firebase, Raspberry Pi, Raspbian, MapServer, JBoss, Microsoft Power Automate, Kubernetes, GIS Cloud
Storage
PostgreSQL, PostGIS, SQL Stored Procedures, SQL Views, SQL Triggers, PL/SQL, MongoDB, Microsoft SQL Server, OVH, JSON, GeoServer, CouchDB, SQL Performance, SQLite, Redis, Redis Cache, SQL Server 7, Google Cloud Storage, Amazon S3 (AWS S3)
Frameworks
Tailwind CSS, Next.js, Ember.js, Bootstrap, Material UI, NestJS, Express.js, Fastify, Materialize, Jest, Cypress, Deck.gl, Yarn, Laravel, Redux, Windows PowerShell, Ionic, Unity, Swagger, JSON Web Tokens (JWT), WIF
Paradigms
REST, Management, ETL, REST API Architecture, API Architecture, Web Architecture, Model Context Protocol (MCP), Mobile Development, Anomaly Detection
Other
GNSS, Cartography, Coaching, App Support, Project Consultancy, QGIS, Satellite Images, GeoJSON, Google Earth KML, Maps, Geospatial Data, Geographic Information Systems, Story Maps, IT Project Management, Consulting, Oracle Spatial, Business Development, Customer Service Representative, Sales Presentations, Pitch Presentations, Remote Sensing, GPS, Windows Subsystem for Linux (WSL), Sentinel 2, Google Earth, Vehicle Routing, Imagery, ESLint, Ubuntu Server, Architecture, Algorithms, Web Development, ETL Testing, GeoPandas, Real Estate, Marketing Mix, Business Law, Human Resources (HR), Tax Accounting, Negotiation, IT Services, Radar Remote Sensing, SingleStore, ESRI Operational Dashboards, Styled-components, ArcPy, Training, ICT Training, YML, CSV, 3D Images, Image Processing, CityGML, ArcGIS API, Mapbox Styling, Apollo Server, PostGraphile, Transitions, Internet of Things (IoT), Axios, Mobile GPS, SAP, Business Ideas, Business, Finance, IIS, SaaS, Full-stack, APIs, Software Architecture, FontAwesome, Solution Architecture, System Design, Cursor AI, API Gateways, Data Migration, Mapping, Airtable, Rasterio, Multiprocessing, PyProj, BIM/CAD, K-means Clustering, Voronoi, Silhouette, API Integration, Geofencing, Geofencing & Geotargeting, Generative Artificial Intelligence (GenAI), OpenAI, Retrieval-augmented Generation (RAG), Prompt Engineering, Machine Learning, Vector Databases, Optical Character Recognition (OCR), Cordova, Full-stack Development, GeoTIFF, NextAuth.js, Bcrypt, Tailwind UI, Nodemailer, GitHub Actions, Railway, Batch File Processing, Time Series Forecasting, Trend Analysis, Dashboards, Time Series, Time Series Data, Multithreading, Concurrency, FastAPI
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