About me
Professional summary
I design and build production software where architecture, data, and interface behavior are tightly
connected—from multi-tenant operational platforms and accessible maps to WebGL/WebGPU tools and
browser-native technical applications.
My recent work uses SvelteKit and TypeScript, supported by Node, PostgreSQL, Python services, testing, and
documented delivery. I am most useful when a team needs senior ownership of both the product surface and
the system underneath it.
- Built and modernized production systems with multi-tenancy, roles, and operational workflows.
- Designed reusable visualization and mapping systems for Nesta UK.
- Led frontend architecture and a four-developer team.
- Built open-source WebGL/WebGPU and computational design tools.
How I work
I take on full-time roles, contract engagements, part-time technical advisory, and fractional architecture /
technical-lead work, including occasional Fractional CTO engagements when that fits. I work remotely across the Americas and
Europe. I'm strongest where architecture, product delivery, and rich interfaces intersect: finance and
regulated-operations systems, data-rich products, and AI-augmented engineering workflows.
Comfortable owning delivery end to end or plugging into an existing team as a senior individual contributor
or lead.
Best-suited roles
Three primary fit clusters — Fractional CTO stays secondary engagement language.
- Staff / Principal Product or Frontend Engineer For teams needing strong frontend architecture, technical product judgment, and production ownership.
- Software Architect / Technical Lead For architecture, migrations, technical direction, and cross-layer decision-making.
- Specialist Consultant For data-heavy interfaces, browser graphics, computational tools, visualization, and technically demanding prototypes.
Foreword
This site is a deliberate craft exercise: lean semantic HTML, clear separation of structure from
presentation and behavior, and performance-aware implementation. A dedicated print stylesheet drops the
interactive background and reflows the content into a paper-ready CV if you print this page — progressive
enhancement that keeps one content model for screen and print. For a shareable HTML résumé, PDF download, or
print without the panel UI, use the Résumé page. It reflects the
same care I bring to client and product work, applied here as a long-running personal build.
Thanks for visiting — the sections below expand on experience, skills, selected work, and earlier
experiments. Analytics here are cookieless and collect no personal data; details in the privacy notice.
Name
Sebastian E. Ferreyra Pons E-mail
sebastian@ferreyrapons.com.ar Website
https://ferreyrapons.com PDF résumé
https://ferreyrapons.com/sebastian-ferreyra-pons-resume.pdf Résumé
HTML résumé · PDF Profiles
GitHub· YouTube· Substack· Bluesky· Mastodon· X Location
Santiago del Estero, Argentina — remote across the Americas & Europe Citizenship
Argentina, Canada Availability
Full-time, contract, advisory, or fractional architecture / technical lead Languages
English, Spanish, French — written and spoken fluently Experience
2025–Present / Escriba Finanzas — Multi-Tenant Legal-Finance Operations Platform
Modern reboot and expansion of a legal-sector credit-operations system originally delivered in
1999–2002. Rebuilt as a commercial multi-tenant web platform using SvelteKit 2, TypeScript, PostgreSQL
row-level security, and Drizzle ORM. Covers credit portfolios, legal cases, payments, reporting, team
invitations, role-based access, and migration from a legacy Classic ASP estate. Includes structured
documentation, Vitest and Playwright coverage, and an engineering-first delivery process. Commercial
product in active development.
2024-Present / Personal R&D — Multifractal Time-Series Prediction Platform
Monorepo research platform combining a SvelteKit frontend, Python ML engine, and custom C++/Rust
shared-library resamplers for multiscale time-series tensor generation. Designed a recency-weighted
temporal representation that preserves high-resolution recent samples while folding lower-resolution
long-horizon context into fixed-shape 3D training blocks. Implemented geometric bin-width ladders,
stacked resampling windows, timeline-coupled time encodings, and DSI/multifractal analysis to guide
segmentation and view construction. Built feature pipelines generating difference, tangent, and
outer-product matrix channels to encode cross-channel structure before modeling. Python stack includes
Hydra, Optuna, TensorFlow/Keras, pytest-benchmark, unit tests, experiment workflows, and documentation.
Benchmarks on large training-style batches show ~20–40× throughput over a NumPy-first reference path,
keeping preparation tractable for series with millions of samples. Independent upskilling project, not
commercial product scope.
2024–Present / Independent Web Development
Independent Svelte/ SvelteKit web development for production sites and promotional platforms. Example: Aires de Río — a residential
development website built with TypeScript, SvelteKit, server-side contact
handling, Node-based deployment, and custom 3D/photogrammetry-based hero visuals. Focused on polished
frontend execution, interactive presentation, performance, and deployment-ready delivery.
2020-2024 / Frontend and Dataviz Developer
Frontend and dataviz developer using Svelte/SvelteKit, XState and Lamb to develop
accessible data vizualization frameworks, tools and websites. Nesta UK, London.
2019-2020 / Frontend Team Lead
Frontend development team lead managing four devs, frontend architect and backend
developer for a CRM system using React on the frontend and a
Python/Flask/SqlAlchemy/PostgreSQL stack on the backend publishing
a REST API service. GoManzanas, Palo Alto, CA.
2016-2017 / CTO, Technical Project Manager and Software Architect
Project manager for Infomerx developing web based administrative systems and
applications. Tasks involved deciding the technology roadmap, hiring, training, directing
& maintaining a development team, interacting with sales & marketing and designing the
architecture of the system based on commercial and technical requirements. Technologies
used included Three.JS, Node.JS, React.JS, Socket.IO and various others.
2015-Present / Participation in Interactive Arts Collective
Visual experimentation, live coding performances with live musical bands and interactive
installations in Santiago del Estero. Tripulantes, Casa Nave, Santiago del Estero, Argentina.
2015-2016 / Web Technologies Workshops for Artists
Organization of educational workshops teaching web technologies like HTML5, CSS and
Javascript for contemporary and conceptual artists. Casa Nave, Santiago del Estero, Argentina.
2013-2015 / Technical Project Manager and Software Architect
Project manager for Ensembleweb developing a gameification
based website for enhancing engagement and performance in sales workgroups for EnsembleWeb,
a Canadian web site development company. Tasks involved hiring, training, directing & maintaining
a development team, interacting with marketing and designing the architecture of the system
based on commercial and technical requirements. Technologies used included Node.JS, Angular.JS,
React.JS, Socket.IO EnsembleWeb
2010-2014 / Wordpress Plugin Development
Consulting, custom plugin design and development for EnsembleWeb, a Canadian web site
development company. EnsembleWeb
2008-2013 / Graphic Design & Technical Consulting
Graphic design, CGI imaging, technical consulting & special purpose software development
for Expressart, an advertising agency based in Santiago del Estero, Argentina.
Expressart
2007 – 2008 / Team Leader & Software Development
Development of software tools for the human resources industry including design
implementation and developer team coordination. The system, based on modern architectural
design, provides a sophisticated desktop user interface but accesses distributed web
services under the hood thus providing a complete user experience while still reaping the
benefits of SOA (Service Oriented Architectures). Responsibilities included maintenance
of the various servers running in the system, of the promotional web site and the
authorship and maintenance of source code in Java, C# 2.0, HTML and SQL for software
destined to run on Windows and Linux. CandidateHunter International
2003-2006 / Project Management & Software Development
Funding and managing a 3-person team in the development of an object oriented graph database
engine and its supporting developer and management tools for Microsoft’s .NET environment
and Sun’s Java platform. This OODB was my design and is intended to support nearly orthogonal
data-persistence facilities for data objects in these platforms. Features being developed
include ACID transactions, multi-server distributed storage nodes and data versioning for
the purposes of auditing and conflict-resolution.
2004-2005 / Website Content Editor
Front-page story editor for JavaLobby.org, a website specializing in the Java developer
community. The main responsibilities involve screening daily Java-related news and writing
small articles with the intent of generating in-depth discussions among the members of the
Java community. These tasks require staying up-to-date in all Java industry developments.
2000-2004 / Ingeniería de Software
Low-level development of high-performance primitive graphics rendering APIs and
components for Java applications including gradient rendering at speeds equalling solid
color filling in that platform. Different versions of these components are licensed
to open-source projects (Kunststoff LnF y Metouia LnF) and a version taking advantage of
hardware acceleration to Jide Software for use in
its component suite y and user interface framework.
2002-2003 / Software Engineering
Development of software architecture and components for internet connected multi-user
server providing multi-company unified facilities for bus seat availability, reservation
and ticket sale for nation-wide remote terminals. This system provides a graphical
display over a map and when there is no direct service between two geographic points,
provides possible connection points based on user-selected time constraints. 2-tier
client/server architecture: Database with business logic in Stored Procedures on the
server and Java technology including JDBC and SWT on the client-side.
1999-2002 / Software Engineering
Development and maintenance of multi-user system for legal firms managing overdue credit
accounts using Java technology including Servlets, JSP, JDBC, JSP, XML, XSL, Dynamic HTML
and CSS. 4-tier client/server architecture: Database, Business logic, Document generation
on the server side and User Interface in the client. Currently running on company
managing 43000+ accounts judicially and extra-judicially on database distributed over
several provinces in northwestern Argentina, synchronized through the Internet. The same domain is
being modernized in the Escriba Finanzas initiative (2025–Present; see above).
1998-2001 / Website Administrator
Web site design, implementation and webmastering for Poder Judicial de la Provincia de Sgo. del Estero.
This site belongs to the judicial branch of power of this province. Everything in this site
including the navigational structure, graphics and animations was designed and created by me.
Although no longer in charge, much of the graphics, animations and source code currently in
use remain my creation as can be verified by the copyright notice in the html source code.
1998-1999 / Manager - Technical Service & Support Department
Head of technical department for the local franchise of Arnet, the largest ISP in Argentina.
This franchise includes all the territory of the province of
Santiago del Estero.
1996-1997 / Technical Consultant - Information Technology
Development of small information systems in Java for companies local to Sgo. del Estero,
Argentina. Personnel training for various organizations in Sgo. del Estero on basic Internet
Skills. Consultant for Icox, a Canadian-Argentine company
providing internet services for Argentine businesses.
Ref. Bruno Schmidt
1993-1998 / Technical Consultant - Graphics and Video
In charge of installation and maintenance of computer systems and digital/analog video
editing equipment. Computer Animation for video. Calibration, digital treatment and
preparation of pre-press originals for color catalogs and flyers. Personnel training to
assist in these tasks, AMP Producciones, Sgo. del Estero, Argentina.
Technical consulting and personnel training, FREDY Publicidad, San Miguel de Tucumán, Argentina.
2D & 3D graphic design. Participation in production of TV commercials for these companies.
1992 / Sales Representative
Sales and promotion of educational material and personnel training for direct sales
and marketing. Grolier Inc, Canada.
1990-1991 / Software Developer
Design and implementation of computer applications and tools, LAN and computer
system maintenance and personnel training. Among applications developed are data
acquisition and control programs for gel electrophoresis of DNA and mathematical
analysis tools, S.U.N.Y. at Stonybrook, biochemistry department.
Ref. Dr. Benjamin Chu
1989-1992 / Freelance Graphic Designer
Freelance graphic design for small companies and businesses in Long Island.
1989-1992 / Programming Assistant
Participation in development of routines in C and Assembly Language for large
programming projects for companies such as Radio Shack/Tandy and Lavalin Engineering
Inc. in Montreal, Canada. SOFTPOWER Inc., New York.
Technical Skills & Delivery Strengths
Product engineer and software architect with deep full-stack, frontend, data-visualization, systems, and
delivery experience. Current work centers on SvelteKit, TypeScript, SQL/NoSQL databases, testing,
documentation, and LLM-assisted development; long-range background includes systems architecture, graphics,
native code, and technical leadership.
Full-stack & production web
Core: TypeScript, JavaScript, Svelte / SvelteKit, React, Node.js, HTML, CSS, Web APIs, REST,
accessibility-minded UI, data visualization, XState, Three.js / WebGL.
Recent shipping stack centers on SvelteKit 2 and TypeScript across commercial multi-tenant software, personal
sites, and R&D frontends. Earlier professional work includes React CRMs, Nesta-era Svelte/SvelteKit data
visualization, and Node- and Python-backed services.
Uses modern LLM coding assistants and agent-style workflows for implementation, review, refactoring,
migration, and documentation while retaining direct code ownership and quality control.
Leadership & delivery
Engineering team leadership, frontend architecture, hiring, technical interviews, mentoring, training, roadmap
decisions, stakeholder alignment, and technology selection.
Direct experience leading development teams across multiple projects, including frontend-architect and backend
work on a React + Python/Flask/PostgreSQL CRM. CTO and technical project-management roles added hiring, training,
directing developers, and aligning engineering work with commercial requirements. Also delivered web-technology
workshops for artists covering HTML, CSS, and JavaScript.
Platform, data & quality
SQL and NoSQL databases — e.g. PostgreSQL (with row-level security), SQL Server, MySQL, MongoDB, and
Elasticsearch / OpenSearch — plus Drizzle ORM, Vitest, Playwright, pytest, technical documentation, migration
planning, and testable delivery workflows.
Current product work emphasizes multi-tenant PostgreSQL with RLS, structured documentation, and automated
tests. Prior stacks include Flask, SQLAlchemy, JDBC-backed multi-tier systems, and legacy database-backed
business applications.
Systems, native code & legacy depth
Systems architecture, interactive graphics, communications, data acquisition and control, operating systems,
utilities, and long-running business systems.
Comfortable across Linux, Windows, and UNIX-class environments, with early-career breadth from PC and
embedded-era platforms through today's cloud-oriented deployments.
Representative languages include JavaScript/TypeScript, Java, C#, F#, C/C++, assembly, BASIC, Pascal, and
Fortran. Historical web and enterprise experience includes JSP/servlets, JDBC, XML/XSL, Classic ASP,
ASP.NET, IIS-era deployments, Socket.IO, and Angular.js-era SPAs — retained where migrations or maintenance
matter, not as the current default stack.
ML / AI engineering
Python, TensorFlow/Keras, Hydra, Optuna, experiment workflows, benchmarking, C++, and Rust performance
libraries.
Personal R&D focuses on multiscale time-series preparation and modeling. The emphasis is engineering depth:
numerical representation, fast native resampling, feature pipelines, experiment automation, and integration with
standard Python ML tooling. Not positioned as commercial ML leadership.
Creative, visualization & tooling
Blender, photogrammetry-informed 3D for the web, Three.js/WebGL, data visualization, Adobe/GIMP design
workflows, WebStorm, and modern editor toolchains.
Earlier professional work included 3D Studio Max, Illustrator, print/video production tooling, CGI imaging,
graphics pipelines, and interactive visual experimentation.
Teaching, communication & commercial context
Extensive teaching, mentoring, and training experience. Background in marketing, advertising, print, radio, TV,
web, and direct sales, useful when engineering work must connect clearly to users, clients, and business
requirements.