César Siancas, Developer in Bangkok, Thailand
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César Siancas

Verified Expert  in Engineering

WordPress Developer

Bangkok, Thailand
Toptal Member Since
August 8, 2018

César has more than 10 years of experience as a WordPress developer and has spent five years working as the senior coder at Mabbly.com, one of the top marketing agencies in Chicago. He has experience building custom responsive WordPress themes, plugin creation, general maintenance, and speed optimizations. César believes communication is the cornerstone of the proper development of any digital project.


WordPress, WP All Import
TestGorilla B.V.
PHP, WordPress, Multilingual Websites, Corporate Websites, JavaScript...
Orderly Health
Figma, WordPress, Content Marketing Platforms, Beaver Builder, PHP, CSS...




Preferred Environment

MAMP, CodeKit, Coda, Tower, OS X

The most amazing...

...project I've worked on was a platform focused on connecting professionals in different areas with entrepreneurs in need of their specific skill set and advice.

Work Experience

WordPress Developer

2024 - 2024
  • Fixed import problems with the WP All Import plugin and handled importing more than 50,000 records into custom post types and custom fields.
  • Installed and set up a business directory plugin and ensured everything was correctly integrated with our import file.
  • Improved the code on the theme and plugins used to optimize the speed of the site and the back end. The plugin had many problems handling large amounts of data.
Technologies: WordPress, WP All Import

Senior WordPress Developer

2022 - 2023
TestGorilla B.V.
  • Updated their current WordPress theme and custom plugin in order to work with multiple languages.
  • Created custom scripts to improve SEO, speed, and monitoring.
  • Automated parts of the translation process (via XLIFF files) and stabilized a deployment process for the different environments we had.
Technologies: PHP, WordPress, Multilingual Websites, Corporate Websites, JavaScript, Databases, Performance Tuning, APIs, CSS, HTML, Plugins, Themes, Full-stack

WordPress Senior Developer

2022 - 2022
Orderly Health
  • Developed the client's new main website using the plugin Beaver Builder.
  • Created custom modules for Beaver Builder to provide easy-to-use and reusable elements for the client to use or update in the future on the site.
  • Was in charge of coordinating and implementing the connection between the client's contact forms to the Salesforce service.
Technologies: Figma, WordPress, Content Marketing Platforms, Beaver Builder, PHP, CSS, JavaScript, HTML, WordPress Themes, WordPress Plugins

WordPress Developer

2018 - 2022
LaGrande Marketing
  • Led the technical SEO optimizations, speed improvements, and maintenance.
  • Handled everything related to WordPress, from theme creation to general maintenance and speed improvements.
  • Built sites using Beaver Builder and custom module creations for this theme.
Technologies: CSS, Front-end, Responsive Web Design (RWD), PSD to WordPress, WordPress Themes, WordPress, Figma, Beaver Builder, Content Marketing Platforms

WordPress Developer

2021 - 2021
  • Took charge of maintaining and extending their custom WordPress theme and plugins that interacted with marketing and call center external services.
  • Set up and tested GTM and Google Analytics for the many requirements their client has.
  • Handled the integrations between their client site with the LeadConduit platform via an API.
  • Managed the integration between different flows in LeadConduit with the external service BlueShift.
  • Created different Zappier integrations in order to connect their different lead sources with LeadConduit, a real-time lead optimization platform that empowers you to take action on your leads by customizing lead flow.
Technologies: Advanced Custom Fields (ACF), WordPress, PHP, HTML, JavaScript, Google Tag Manager, Google Analytics, GitHub, APIs, Zapier

WordPress Developer

2021 - 2021
Praxent (via Toptal)
  • Fixed SEO-related technical problems for better performance.
  • Owned the creation of Gutenberg blocks since the client was moving aways from the WPBakery builder.
  • Spearheaded the general maintenance and improvements on the site.
  • Improved the current theme structure setting the path for a Gutenberg-based site.
Technologies: Advanced Custom Fields (ACF), WordPress, Gutenberg Editor, Front-end, Back-end

Technical WordPress Developer

2020 - 2021
Bridgecrew (via Toptal)
  • Developed the new theme from scratch. This was a responsive theme that used the Tonik starter theme as a basis along with AFC blocks for customization.
  • Owned the general maintenance of the site as part of my role.
  • Fixed bugs and created custom required functionality.
Technologies: Advanced Custom Fields (ACF), WordPress Themes, WordPress Plugins, WordPress, PHP, CSS, HTML

Senior WordPress Developer

2020 - 2020
The Dancel Group, Inc (via Toptal)
  • Developed a custom-made plugin in charge of scheduling publications shared on social media, which also included an import process of all their data.
  • Created a plugin that integrates with WooCommerce and their subscription plugin.
  • Built a custom WordPress theme from scratch using ACF for the back-end.
Technologies: WordPress, PHP, CSS, HTML, JavaScript, Advanced Custom Fields (ACF)

Senior WordPress Developer

2020 - 2020
RoshReview (via Toptal)
  • Owned the creation of the new multisite environment, including the preparation and organization of their current website into different child sites.
  • Created the main WordPress theme for the principal site using Tailwind CSS as our base and Tonik, Starter Theme.
  • Reviewed child themes and updated the files to accomplish better performance.
  • Conducted technical SEO maintenance and improvements to achieve the company's goals.
Technologies: Back-end, Front-end, Page Speed Optimization, Tailwind CSS, WordPress Multisite, WordPress, Advanced Custom Fields (ACF), Figma

Expert WordPress Theme Developer

2020 - 2020
LyraThemes (via Toptal)
  • Oversaw and was in charge of creating custom themes that adhered to WordPress development standards.
  • Developed a custom plugin using object-oriented programming.
  • Maintained and fixed bugs in WordPress themes and plugins.
Technologies: PHP, CSS, HTML, WordPress

WooCommerce Developer

2020 - 2020
GAMING DOT ME LLC (via Toptal)
  • Created a plugin that connects with a license number provider to be distributed with WooCommerce.
  • Integrated a custom-made license generator with WooCommerce.
  • Created the necessary back-end administration panel to handle all the information related to licenses.
Technologies: WordPress Plugins, REST, APIs, WordPress

WordPress Engineer for Plugin Development

2020 - 2020
Benzinga (via Toptal)
  • Integrated a plugin with the Dictionary.com API.
Technologies: PHP, WordPress Plugins, REST, APIs, WordPress

WordPress Expert

2019 - 2020
Constructor.io Corporation (via Toptal)
  • Maintained WordPress websites including theme updates using ACF.
  • Created Zendesk themes.
  • Performed quality assurance as needed.
Technologies: Front-end, Responsive Web Design (RWD), PSD to WordPress, WordPress Themes, Zendesk, Advanced Custom Fields (ACF), WordPress

WordPress Developer

2019 - 2020
LazerPro (via Toptal)
  • Oversaw the general maintenance, plugin creation, and migration of their news and listing site from their old non-WordPress platform to WordPress.
Technologies: WooCommerce, WP Engine, WordPress

Back-end WordPress Developer

2019 - 2019
XLR8R Media, Inc. (via Toptal)
  • Headed the entire migration from the Tempest platform to a WordPress one.
  • Created a plugin that integrated Bandcamp subscribers with WordPress.
  • Took charge of the general maintenance of their site.
Technologies: PHP, WordPress Plugins, WP Engine, WordPress

WordPress Expert

2019 - 2019
The Chempetitive Group, LLC. dba CG Life (via Toptal)
  • Developed a responsive WordPress theme from scratch.
  • Played a vital role in the general optimization of the site.
  • Was in charge of handling the maintenance of the site.
Technologies: WordPress

WordPress Developer

2018 - 2019
RoshReview (via Toptal)
  • Improved the overall site speed for better engagement with potential clients.
  • Developed new WordPress themes according to new requirements, using ACF, Gutenberg, and API integration.
  • Took charge of the general maintenance and bug fixing of their current platform.
Technologies: Front-end, Responsive Web Design (RWD), PSD to WordPress, WordPress Themes, WooCommerce, WordPress

Senior Coder

2017 - 2019
  • Developed an entire WordPress theme from scratch; it was responsive and was built following the recommended speed improvements.
  • Designed a plugin that created all the necessary elements in the backend to make their reservation system work.
  • Built a plugin using WordPress REST API to allow the interaction between their mobile app and their backend.
  • Added more functionality constantly and built custom reports.
Technologies: PHP, CSS, Front-end, WordPress Themes, Sass, WordPress, JavaScript, HTML

Senior Coder

2017 - 2017
  • Developed WordPress themes and plugins for different clients.
  • Implemented the image-to-layout workflow (PSD-to-theme conversion or similar).
  • Converted the old, static website to a WordPress site for Flordecana.com.
  • Maintained the websites for Republicofhumanity.org and M4angency.com.
Technologies: PHP, CSS, Front-end, Responsive Web Design (RWD), WordPress Themes, WooCommerce, JavaScript, Sass, WordPress

Senior Coder

2012 - 2016
  • Developed the WordPress themes and plugins for a variety of clients.
  • Maintained and extended the WordPress sites for multiple clients.
  • Introduced the image-to-layout workflow, including PSD-to-theme conversion.
  • Implemented speed improvements in WordPress sites for different clients to make them follow Google's speed standards, accomplishing an average of. three seconds on different speed test sites.
  • Developed the WordPress theme for a variety of websites, including Drinkkoia.com, Iconid.com, Thegarage.northwestern.edu, Briahs.com, Precisionsoftware.com, and Nationalvanlines.com.
  • Built the WordPress theme, completed the API integration with their system, and improved site speed for Prohabits.com.
  • Integrated API with the NeonCRM and developed a WordPress theme for Smallbusinessadvocacycouncil.org.
  • Created a PHP system using the Kohana framework for Advisor.tv.
Technologies: PHP, CSS, Front-end, WordPress Themes, WooCommerce, Sass, WordPress, JavaScript, HTML

Programmer Analyst

2008 - 2010
Hidrandina S.A.
  • Implemented the client management module, interviewed users, and migrated data from the old system.
  • Led the analysis and development of the cuts and reconnections module.
  • Collaborated with the quality control team to create new versions of the quality control module for their new system.
Technologies: C#, .NET, SQL


An entrepreneurial platform that allows professionals to have a space to display themselves and their knowledge through videos.

I was in charge of creation from scratch, including the front end and back end, along with the general maintenance.


I handled the development of this theme, as well as the plugins that integrated with their system. My work also included ensuring the site was optimized to have a good rank on the main website speed tests.


I co-founded this startup, which consists of a platform that allows business owners to obtain clients through customized offers. The entire back end is built in WordPress, and I used a REST API to connect the data and logic with a React application.
2002 - 2007

Bachelor's Degree in Computer and Information Science

National University Pedro Ruiz Gallo - Lambayeque, Peru


REST APIs, WordPress REST API, WordPress API, Google Maps API, jQuery


Coda 2, MySQL Workbench, PhpMyAdmin, MAMP, Tower, Git, Avocode, Zeplin, Advanced Custom Fields (ACF), Coda, Gulp, Grunt, Terminal, GitHub, Gutenberg Editor, Google Analytics, Zapier, Figma, WP All Import


CSS, HTML, PHP, Sass, Less, JavaScript, SQL


WordPress, WooCommerce, OS X, Zendesk


Responsive Web Design (RWD), REST, Object-oriented Programming (OOP)


MySQL, JSON, WP Engine, Databases


Tailwind CSS


Freelancing, HTML to WordPress, WordPress Themes, PSD to WordPress, PSD to HTML, CodeKit, Transmit, WordPress Plugins, Ajax, APIs, Back-end, Front-end, Gravity Forms, Page Speed Optimization, WordPress Multisite, Google Tag Manager, Beaver Builder, Security, Content Marketing Platforms, Multilingual Websites, Corporate Websites, Performance Tuning, Plugins, Themes, Full-stack

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