Hi! Hello! Hallo!

I am an Entrepreneur and Full-Stack Developer, born in Buenos Aires, Argentina 🇦🇷, now living in Berlin 🇩🇪 with more than 15 years of coding experience (PHP, Node, React, Next.js enthusiast).

In 2013 I have co-founded EntrenaYa, a B2C & B2B fitness subscriptions marketplace, with more than 800 gyms and fitness centers from LATAM working with us.

Trained by great business accelerators such as 500 Startups & Startup Chile.
Problem solver. Optimistic. Lateral thinking. Sagittarius. Musician. Cook. Wine Geek.

Contact information

jamarks at gmail dot com

Something I've been working on the last few weeks

Bye, Business Card. Hello, QIQR.

  • Nextjs (React Framework) + Nodejs under Nextjs/API + + TailwindCSS - Deployed in Vercel.
  • vCard + QR Generator, using S3 Bucket and Firebase.
  • NextAuth for authentication with Linkedin, Google and Twitter.
Its QIQR because it is „Quicker“.
Business Cards are an obsolete technology. How many of your phone contacts are no longer valid? Get your innovated QIQR on your phone, share your data and be aware whenever any contact change any of their contact data. This is my QIQR!
7-2021 | qiqr.app

Last Freelance Projects

Dreamly | Main Full-Stack Developer

  • Nextjs (React Framework) + Nodejs under Nextjs/API + TailwindCSS - Deployed in Vercel.
  • NodeJS Express Server: API Rest - PostgreSQL with Sequelize ORM - Deployed in Heroku.
Out of the thousand offers out there, we want to make sure that the one that really suits you finds you while keeping your inbox clear of spam.
12/2020 - 4/2021 | dream-ly.com

Work Experience

BEON Tech Studio | Growth Engineer

5/2020 - 6/2021 | https://beon.studio
I introduced and implemented growth strategy techniques to scale Sales and Hiring processes of one of the most promising IT staff augmentation companies in Latam, in an already very overcrowded and growing industry.
  • Initiate and orchestrate lead-generation semi-automated programs across different and connected platforms and help grow Beon's sales funnel and IT candidates audience.
  • Create original sales-enablement tools to help the sales team deliver a compelling story to prospect customers.
  • Develop original content and copywriting for emails, website, blogs, presentations and other collateral.

Some of the tools I used in daily basis: Reply.io, Salesforce & Hubspot CRM, Zapier, Google Sheets Api, Trello, Workable, Google Analytics and Google Tag manager, Visual Studio Code, Postman among others

ENTRENAYA | Co-founder & Full-Stack Developer

Buenos Aires (AR), Santiago de Chile (CL), Mexico DF (MX) 2013-2020 | https://www.entrenaya.com.ar
The largest B2C fitness platform in Latin America, with more than 4,500 fitness and wellness plans available in over 700 gyms in the region. We also offer a B2B membership as a corporate benefit for employees, with access to more than 350 fitness, spa and beauty facilities.
  • Over 60,000 transactions in the last 4 years and USD 500.000 revenue.
  • MVC based on JAVA Groovy on Rails and PHP-MYSQL hosted in AWS (Elastic Beanstalk, RDS, S3, etc.).
  • Integration with Payment Systems in Argentina (MercadoPago), Chile (PuntoPagos) and México (Conekta).
  • Accelerated in Mexico DF with 500 Startups (2014).
  • Backed by Startup Chile Gen 10 (2015). Press release here.
  • Recognized as one of the best Sports-Tech Startups and featured in many press articles, such as this one by Insight Success.

Some of the tools I used in daily basis: Amazon SES, Amazon EC2 and Elasticbeanstalk, Route53, MySQL , Pipedrive, Google Sheets, Google Analytics and Google Tag manager, Google Adwords, Groovy Tool Suite, MercadoPago(AR) - Conekta (MX) - WebPAY (CL) Payment Systems API among others.

CONSULT-AR | Tech Lead & Full-Stack Developer

Buenos Aires (AR) 2010-2013 | https://consult-ar.info
Developed, mantained and scaled an in-house e-commerce content manager system for over 100 LATAM travel agencies. We experienced an average of 65%
  • MVC based on PHP & MySQL.
  • XML Web Services - API REST integrations with airlines, cruises, cars, tours and hotels reservation systems.

Some of the tools I used in daily basis: PhpMyAdmin, PHP & MYSQL, Google Analytics, Google Adwords, Payment Systems API.

FREELANCE | Full-Stack Developer

Buenos Aires (AR) | Los Angeles (US) 2006-2010
  • PHP / MYSQL, ASP, ASP.net, SQL Server - Bootstrap UI - JS CSS HTML.
  • Marketing Email Senders / Email themes.
  • Wordpress Themes development.
  • Wordpress WooCommerce custom wigets and integrations.
  • Backend and Frontend.
  • Integrations with 3rd party services: CRM's, Bulk SMS Services.
  • Cross-browser Responsive Web Apps.
  • Social Networks scraper for B2B growth.
  • SEO Optimization, SEM, A/B Testing.

TEVELES ASOCIADOS | ASP.NET & SQL Server Full-Stack Developer

Buenos Aires (AR) 2005-2006
  • Migrated a huge Visual Basic ERP to a ASP.NET web based cloud ERP.

OMINT | ASP.NET & SQL Server Full-Stack Developer

Buenos Aires (AR) 2004-2005
  • ASP.NET + SQL SERVER Backend developer.

SMS | Visual Basic & SQL Server Developer Jr.

Buenos Aires (AR) 2002-2004
  • Visual Basic and MQ SQL Server based in-house ERP for mid-large size companies.


  • Spanish 🇦🇷 Native speaker.
  • English 🇺🇸 Fluent speaker.
  • German 🇩🇪 A2 Level and studying. Aspiring to be fluent.

Recent training

NodeJS, Express & MongoDB (oAuth, Performance, Testing, Api REST, etc)
Coursera 10/2020
Certificate: Here
React JS Intensive Training
CoderHouse 08/2020
Certificate: Here
B2B Growth Marketing
Certificate: Here

Formal education

Information Systems Engineer
Universidad CAECE (AR) 2004-2008
Bachelor's Degree Information Technology & Computer Science
ORT Argentina (AR) 1998-2002