Sebastian Ferreyra Pons

Software Architect - Interactive Graphics Designer

About me






About me


Honoring the engineering intention behind the design of CSS/HTML of separation of presentantion and content, printing this page outputs the information as a CV.

Personal Information


Sebastian E. Ferreyra Pons




Mitre 385
G4200DKG Santiago del Estero


(54 9 385) 525-8591

Date of birth

September 7, 1973

Place of birth



Argentina, Canada


English, Spanish, French
all written and spoken fluently



Three terms of advanced courses in mathematics, computer science and physics at S.U.N.Y. (State University of New York) at Stonybrook.


Grades 11 and 12 at Smithtown High School East, St. James, NY. Including elective college level courses on computer science, mathematics and analog and digital electronics.


Grades 7, 8, 9 and 10 at F.A.C.E. (Fine Arts Core Education), Montreal, Quebec, Canada. F.A.C.E. is a bilingual (English and French) school with academic orientation toward the arts.


Primary education in Spanish in Santiago del Estero, Argentina except 1982 finished in Flagler Elementary School, Miami, Florida.


2020-Present / Frontend and Dataviz Developer

Frontend and dataviz developer using Svelte/Sapper, XState and Lamb to develop accessible data vizualization frameworks, tools and websites. Also designing specialized data structures and using WebGL to optimize download speeds and 2D rendering pipelines of large datasets. 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 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, 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.

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.

Acquired Skills


Systems Architecture, Interactive Graphics, Communications, Data Acquisition, Control, Operating Systems, Utilities

Operating Systems:


Computer Languages:

JavaScript, Java, C#, F#, C/C++, Assembler for MC68000, 80x86, 8080/8085/Z80, BASIC, PASCAL, FORTRAN

Web Standards:


Software Platforms & Computer Programs:

Node.js, Microsoft Internet Information Server, MySQL Server, Microsoft SQL Server, Idea Webstorm, Eclipse, Sun Forte/Netbeans, Autodesk 3D Studio MAX, Blender, Adobe Photoshop, GIMP, Macromedia Flash, Adobe Illustrator, Macromedia Freehand, Corel Draw, Adobe Page Maker, Adobe Premiere, Microsoft Office, Autodesk Animator Pro, etc.

Other skills:

Extensive teaching and training experience. Marketing and advertising experience in print, radio, TV and the web. Direct marketing experience.


Stateless Webgl Shader Particles

Screenshot of GPU Particles Demo. An experiment created while developing the particle vertex and fragment shader code used in this website. While my site is effortlessly using around 5000 GPU particles and the demo starts with 30000, on a decent machine a GPU can handle quantities around the hundreds of thousands.

Audioreactive 2D Canvas Particles

Screenshot of openvjkit. The current result of various live coding sessions during live music performances using 2D Canvas and the Web Audio APIs. You need to grant the page access to your microphone and permission to open a second window for displaying the graphical output as it is intended to run on two monitors. While not easily accesible, it also has hard coded MIDI controller functionality that you can adapt if you download the gh-pages branch from the github repo.

2D Canvas Game Experiment

Screenshot of game demo. A small experiment written while teaching about game coding. It's using Box2DWeb for physics and the HTML Canvas 2D API.


Screenshot of vminpoly demo. A polyfill for the newer CSS3 distance units and some media queries.


While there are more experiments that I've built over time that I want to publish, I'm still working on this website so hang on and they'll start showing up as my time allows! In the meantime you may check out my old website.


Collections: Multivalue-per-key Maps

The Java Collections API in java.util.* is a very powerful and fundamental toolkit for managing sets of objects and is used in practically all facets of software development, from low-level caches, to O/R mapping, to GUIs.

However, occasionally we have needs that extend beyond the basic functionality provided in the API. One very common need not handled by the collections framework is to provide maps that can hold many values for a particular key, much like databases feature non-unique key indexes. Having such a collection class would make this job very simple in Java.

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Algorithms: Phonetic Coder for Spanish Words

Sometime ago I posted some code which ranks names according to their similarities based on Levenshtein's word difference algorithm. In this article I mentioned I had developed an algorithm to encode names quasi-phonetically according to their pronounciation in Spanish, much in the spirit of Soundex and Metaphone.

Since then, I've received a few requests by email with respect to this algorithm so I think it would be good to answer them all in a single Java Tip, while simultaneusly showing how to use Regular Expressions efficiently in Java.

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Technique: Generic Linked Lists through Inheritance

Although the java.util.LinkedList class included in the JDK is good enough for most cases requiring linked lists, sometimes conditions will arise when it might not be as useful.

Here I propose an alternative implementation using a combination of generics and inheritance optimized for better memory economy and possibly a slight increase in speed, although the latter should be barely noticeable. This example will also illustrate some interesting applications of generics.

To understand where I'm coming from I'll need to explain some things about how Java stores objects in the heap and how this affects the standard LinkedList implementation.

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Persistence Layers

As I undertake my first project management role, where Ill be leading a really small group of 3 developers (myself included) into an agile development effort, Im allowing myself to look at all the unconventional technologies on the look out for interesting innovations before the design is completely fixed. I will however keep a conservative attitude so as not to get too excited about the toys to be found out in the wild (wild toys might eat your project and your budget!).

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Text: Human Names Similarity using Levenshtein Algorithm

Using the previously posted Levenshtein Edit Distance method, this one builds upon the functionality to provide a name similarity ranking.

The benefits it provides over using plain LD is that it is indifferent to the order a person's name is written, thus being very useful for sorting results of name searches.

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Text: Levenshtein Word Distance

Here's a small implementation of the Levenshtein Word Distance algorythm written in Java.

The algorythm is good for measuring edit distance between two words and is normally used for spell checking and similarity sorting, but I've been told it can be used for other things as well. If you want some in depth explanation of how it works check out this site or this one that has a nice little applet showing its internals at work.

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Swing: Tiling Windows

JDesktopPane as it is doesn't provide tiling and cascading. Here's the routine for tiling. Its priority is to get as many windows as possible to have the same size. Here's the code cascading windows.

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Swing: Cascading Windows

JDesktopPane as it is doesn't provide tiling and cascading. Here's a simple routine for cascading.

The code is implemented in static methods for simplicity but some might prefer to include the methods in a subclass of JDesktopPane or a DesktopManager.

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Graphics: Painting Textures Fast

Following the recent Java2D discussion some of you might be wondering how to put some of that information to good use. A deeper understanding of why TexturePaint results in lower preformance can be found in that thread.

Here's a simple way to paint an arbitrary Java2D Shape with a texture using all the hardware acceleration the current rendering pipelines can provide. This routine, although still having lots of room for important optimizations, is a lot faster than ye' old TexturePaint.

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Face to face with Java2D

Woa! Don't fire up those flame-throwers just yet! This isn't a thread about why native code is better, etc, etc. I mean to say that Java2D could fly just using better Java code.

Take Color, GradientPaint and TexturePaint and the low-level pipelines that actually paint stuff with these classes for example. Here are three implementations of the Paint interface that really make me wonder what's going on over at Sun.

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