Marcela Hrdá, Developer in Bratislava, Slovakia
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Marcela Hrdá

Verified Expert  in Engineering

Single-page Applications (SPA) Developer

Bratislava, Slovakia
Toptal Member Since
June 5, 2017

Marcela is a full-stack developer with more than 3 years of experience developing single-page web applications and REST APIs, managing smaller projects, supervising junior software engineers, and creating architectural design. She has a passion for clean code and a strong inclination to functional programming. She also enjoys competitive coding. Marcela likes challenges and is looking for projects that can help her improve professionally.



Preferred Environment

Git, Vim Text Editor, Linux

The most amazing... source project I created is a library that helps achieve an excellent user experience with validated forms written in React.

Work Experience

Full-Stack Developer

2013 - 2016
  • Co-created 3 single-page web applications as one of core team members.
  • Created an open-source library for validated forms in React.
  • Supervised junior software engineers.
  • Managed smaller projects.
  • Consulted on the architectural design for projects.
Technologies: Amazon Web Services (AWS), Redux, React, JavaScript, Firebase, PostgreSQL, Dart, Python

Back-End Developer

2011 - 2011
  • Created customized configurations for parsing, storing, and displaying collected meteorological data.
Technologies: Java

React Validation Library | Open Source
This is a client-side validation library that aims for an excellent user experience.

The supported features include an automatic re-calculation of the validity when the user changes the input value, suggestions on showing/hiding the validation result, easy definition and usage of custom validation rules, conditional validations, validation of multiple fields, asynchronous (server) validations, and customizable debouncing/throttling for performance optimization.

The API is easy enough to use and very flexible at the same time; this library can be easily combined with other validation approaches.

Wordy | SPA
Wordy is a single-page application that connects customers who need proofreading and copy-editing with English editors. Features include job bidding, a payment and invoicing system, an order log, a chat, support for organizations, different user roles, integrations with Google Drive and Dropbox, and more.

I supervised the junior engineers, co-created the architectural design, and coded some of critical pieces of the project.

For example, I designed and coded payment system that met complex business requirements involving credits, bonuses and refunds, and provided strong guarantees (solving issues with a non-transactional database and unreliable internet connection).

Internal Training Tool for Raiffeisen Bank | SPA

This single-page application is a simulation of a real banking environment and is used as a training tool for banking associates. The main part of the system is a complex form used for entering and processing loan application data. The application supports several different user roles that have very different responsibilities and rights, and can also track user interaction and compute statistical analysis of work efficiency during the simulation run.

I created a major part of the client-side code, and helped in setting up the hardware and system architecture of the final product.

I also managed a follow-up project and my main responsibilities in this project were technical communication with the client, organizing and supporting the development and testing, improving the system architecture, and installing the hardware infrastructure.

Fanligy | SPA

A fantasy-league game customized for Slovak market, coded as a single-page web application. The user can select a team consisting of football players and receives points for real-life events according to a given formula. Unfortunately, this project is no longer available, as its owner decided to shut it down.

I was responsible for back-end part of this project which included an integration with data providers and game logic implementation (processing users' rosters, computing scores and winners, auto-adjusting membership statuses, sending account-related notification emails, and more).

Semifinalist in Google Code Jam

Google Code Jam is a world-wide coding competition in solving challenging algorithmic puzzles. I advanced to semifinals in 2015. (Handle: aklecram.)

Bronze Medal in International Physics Olympiad (IPhO)

I won a bronze medal in the International Physics Olympiad in my senior year of high school.

Implementation of a New Algorithm in Relativistic Computational Chemistry | Research Paper
Co-authored a scientific research paper called:
M. Hrdá, T. Kulich, M. Repiský, J. Noga, O. L. Malkina, V. G. Malkin: Implementation of the Diagonalization-Free Algorithm in the Self-Consistent Field Procedure Within the Four-Component Relativistic Scheme, J. Comput. Chem. 2014, 35, 1725–1737.

This paper is based on a proposition of a new and very promising algorithm that can significantly speed up SCF procedure (one of basic algorithms used in computational quantum chemistry).

I enhanced the original algorithm, solving issues with its stability, reliability and efficiency. I have also run many benchmark calculations to tune the algorithm performance to its maximum.

The paper presents the enhanced algorithm along with a quantum-chemistry proof of its guarantees, documented the benchmark calculations and resulting recommendations for optimal parameter choice, and a generalized version of the algorithm that can be applied to relativistic quantum chemistry.


Java, JavaScript, Python, Dart


Redux, Django, Express.js




Git, Vim Text Editor


Algorithms, Data Structures, Single-page Applications (SPA)


Functional Programming


Firebase, Linux, Amazon Web Services (AWS)



2010 - 2012

Master's Degree in Solid-State Physics

Comenius University, Faculty of Mathematics, Physics and Informatics - Bratislava, Slovakia

2007 - 2010

Bachelor's Degree in Physics

Comenius University, Faculty of Mathematics, Physics and Informatics - Bratislava, Slovakia