Marcel Duran
(updated March 2010)Work Experience
9/2008 - present, Yahoo! Inc.
10/2009 - present, Front End Engineer, Search- Web Performance Optimization and RTL/BiDi issues.
9/2008 - 10/2009, Front End Engineer, LatAm Frontpages- Applied performance best practices on LaTam (Brazil, Mexico, Argentina, USA spanish, Colombia, Venezuela, Chile, Peru) frontpages, when all pages were over the SLA, dropping significantly the overall page load time achieving better results beyond the expectation, improving the final user experience and saving network bandwidth.
- Created and developed an internal tool during my spare time using JavaScript, YUI, PHP and MySQL, for monitoring oversized/not optimized images across Yahoo! properties, warning/emailing the responsible team with reports, improving the page performance on page load measurements.
- Refactored the LatAm frontpages HTML, CSS and JavaScript cutting in more than half the number of requests and page sizes.
- Attended a performance workshop leaded by Nicole Sulivan where she compared the prior LatAm frontpage with the refactored one pointing out the excellent usage of some performance best practices.
- As a front end performance expert, provided performance consulting for different LatAm teams.
- Proposed a better solution for ads team in order to unblock page rendering and promote more parallel downloads in all properties which is already in their roadmap for next generation ads instrumentation. Proved to be better with several tests, data and charts.
- Code reviewed some JavaScript codes across different teams and properties usually pointing out performance caveats.
- Refactored the entire JavaScript code from LatAm frontpages having no warnings from JSLint code quality tool.
- Created and developed a hack during my spare time using JavaScript, YUI and PHP on top of an internal sprint management tool where its interface is now presented as a SCRUM board-like application helping remote members of geographically distributed teams to sync up with team's stories and tasks status. With easy and intuitive draggable interface moving tasks across columns became very efficient and also provides a presentation mode, useful for displaying the SCRUM board on a big screen.
Throughout Yahoo! experience- As a team player, always worked in SCRUM teams, focusing and helping the process.
- Attended several tech-talks from introduction to Haskell, Erlang and Thrift to advanced performance techniques.
- Very participative on internal discussion lists, specially those related to front end development and performance.
- Presented some tech-talks with different subjects such as Functional JavaScript, Front End Performance Techniques and JavaScript Design Patterns.
- Created several Greasemonkey scripts for different purposes from automating repetitive tasks to enhance JSLint web tool.
4/2006 - 8/2008, Voxel Ltd.
1/2008 - 8/2008, Engineering Manager, White Label- Built and led a team of engineers through technical design and implementation, in C#, JavaScript and SQL.
- Oversaw technical direction, scheduling, feature decisions, and coordination with other groups.
- Designed and implemented in C# bots for e-ticket issuing and risk analysis queuing system.
- Designed and developed .NET data importer web service integrating different tour agencies web sites using XML data structure to push customers orders in order to issue their flight tickets.
9/2007 - 12/2007, Software Engineer, Pay Cruise- Dramatically changed the previous version of billing process algorithm applying an heuristic procedure based on passenger's expenses along the cruise length, reducing customer's billing statement entries by 80% and reducing the charge backs figures from 14% to 0.2% during South America's summer seasons of Island Cruises ships which led to implement the system onto Royal Caribbean ships.
- Refactored the system in order to be compliant with the Payment Card Industry Data Security Standard, using high level cryptographic algorithms, increasing the data storage/flow security.
1/2007 - 9/2007, Software Engineer, Cruise Search- Primary Engineer from initial design through launching the public web application.
- Designed web application to support both ASP and B2C models, currently being used by more then 100 tour agencies and above one thousand users per day resulting in approximately 50 reservations daily.
- Drove performance analysis and optimization for web requests fulfilling the YSlow 13 rules and improving the user experience response.
- Developed a FTP flat file downloader in C# which daily parses and imports into database updated cruises prices and a watchdog that reports when error or abnormality on FTP downloader occurs.
- Implemented the i18n features of the product using JSON data structure featuring language changing on-the-fly.
4/2006 - 12/2006, Software Engineer, Naja.NET Framework- Co-created the project original idea which became the base framework for all web projects in the company used by more than 50 developers internally.
- Oversaw feature decisions, algorithm analysis and coordination with other team members.
- Developed in C# and JavaScript the core of asynchronous method calls providing easy-to-use AJAX for developers.
- Performed browse compatibility tests and adjustments assuring the same control behavior on the most popular web browsers.
- Documented and implemented an on-line help for Naja.NET including methods descriptions, syntaxes and code examples.
- Developed in JavaScript algorithms for data sorting/filtering with optimization.
- Designed and developed a complete IATA airport database with ranking and its data retrieval using an optimized SQL stored procedure based on relevance.
Throughout Voxel experience- Served on the Hiring Committee which makes offer approval or rejection on interview candidates.
- Recognized strong interviewer for engineering candidates and further candidates initiation on the company development environment.
Education
- B.S., Computer Science, Universidade Presbiteriana Mackenzie, 2007. GPA 3.5cum laude.
- Data Processing Technician, Fundação Instituto Tecnológico de Osasco, 1997.
Awards
- Yahoo! YOU ROCK Award, 2010
Courses Taken
- Agile Training - SCRUM, Yahoo!, 2009, 20 hours.
- Project Management, Fundação Instituto de Administração (PMI R.E.P.), 2008, 160 hours.
Skills
- Performance driven developer.
- Outstanding JavaScript skills, including full application development, AJAX, and cross browser compatibility.
- Proven ability to analyze complex technical problems and produce solutions, both individually and in teams.
- Solid experience with structural HTML, CSS and XML/XSL/XPath.
- Experience with in PHP, Java, C#, MySQL, T-SQL, C/C++.
- Extensive experience with both Unix and Windows environments.
- Solid experience creating and architecting general web interactive applications and scalable web applications.
- GoF design patterns knowledge.
Spoken Languages
- Native speaker of Portuguese.
- Fluent in English.
- Intermediate in Spanish