Ondrej Sramek, Developer in Uhersky Brod, Czech Republic
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Ondrej Sramek

Verified Expert  in Engineering

Python Developer

Uhersky Brod, Czech Republic
Toptal Member Since
February 26, 2015

Ondřej is a senior software engineer with over 13 years of professional experience; he's been working as a remote contractor for the last nine years. Backed by a solid background in computer science, Ondřej has helped companies successfully launch a range of projects from internal services to customer-facing web and mobile apps.


Python, Django, JavaScript, React, Tailwind CSS, GitLab, Git, Docker, Terraform...
Kiwi.com (via Fragaria Ltd.)
GitLab, Koala, Mypy, Docker, Sentry, Datadog, Falcon, Celery, SQLAlchemy...
Rail Pros Field Services (via Toptal)
ReportLab, Celery, JavaScript, Django, Python




Preferred Environment

Git, Visual Studio Code (VS Code), MacOS, Python, JavaScript, iOS, Swift

The most amazing...

...software I've created is a media management platform. I contributed to the Python back end, native iOS app, and JavaScript web client development.

Work Experience

Senior Full-stack Developer

2020 - 2021
  • Authored an initial data model, a GraphQL API and several third-party API connectors of a digital token investments platform.
  • Trained engineers who joined the team and helped grow the team to 10 people.
  • Spotted multiple performance issues soon and optimized those heavily.
Technologies: Python, Django, JavaScript, React, Tailwind CSS, GitLab, Git, Docker, Terraform, Graphene, GraphQL, PostgreSQL, Amazon Web Services (AWS), React Apollo

Python Developer

2018 - 2019
Kiwi.com (via Fragaria Ltd.)
  • Contributed to the development of a new important internal Python-based service.
  • Adhered to strict code quality assurance process: merge requests, code reviews, code formatting, code analysis, CI, etc.
Technologies: GitLab, Koala, Mypy, Docker, Sentry, Datadog, Falcon, Celery, SQLAlchemy, OpenAPI, REST, Python

Python Developer

2017 - 2018
Rail Pros Field Services (via Toptal)
  • Implemented new functionalities to an internally developed payroll web application.
  • Set up integration/regression tests and processes to ensure the correctness of the main payroll generation procedure.
  • Identified multiple performance bottlenecks and made significant speed improvements with very simple adjustments.
  • Used the ReportLab PDF creation library extensively to generate contractor invoices and new types of reports.
Technologies: ReportLab, Celery, JavaScript, Django, Python

iOS Developer

2015 - 2017
Microton s.r.o.
  • Developed a new native iOS client for a cloud storage provider to replace an insufficient legacy solution.
  • Set up process and scripts to produce, sign, and publish 25+ white label apps from a single codebase.
  • Reimplemented several iOS and macOS apps using Swift and adapted them to current system versions.
  • Proposed and implemented multiple UX improvements to provided designs.
Technologies: Fastlane, Python, Alamofire, Realm, Core Data, Cocoa, Cocoa Touch, Swift

Python and iOS Developer

2014 - 2014
5o s.r.o.
  • Led the development of the back­ end and API for a service arranging hostesses, entertainers, and venues for customers’ events.
  • Ensured the deployment of first versions to Heroku and later prepared Fabric scripts for easy deployment to VPS.
  • Took sole responsibility for the development of the iPhone client with user login, catalog browsing, order placing, and profile settings.
Technologies: JavaScript, Cocoa Touch, Objective-C, REST APIs, Django, Python

Full-stack Developer

2013 - 2014
Paninaro Digital s.r.o.
  • Designed and developed the back ­end and API for a SaaS start­up solving media management and sharing.
  • Created an SPA web ­client based on Backbone and Marionette frameworks.
  • Developed a lightweight client running on Raspberry Pi with a simple web control panel.
  • Quickly grasped new technology (iOS development) and contributed significantly to the development of the iPad client.
Technologies: Cocoa Touch, Objective-C, Raspberry Pi, Bootstrap, Marionette.js, Backbone.js, jQuery, JavaScript, Fabric, Flask, REST APIs, Django, Python

Python Developer

2012 - 2013
Scarfbot Technologies s.r.o.
  • Collaborated to develop a tailor-­made back end for a network of eCommerce sites.
  • Successfully refactored system-critical cart and ordering processes.
  • Created an in-house affiliate system with web interface for affiliate partners.
Technologies: Redis, Bootstrap, Backbone.js, JavaScript, Django, Python

Python Developer

2011 - 2012
Fragaria s.r.o.
  • Led the development of a new entertainment portal.
  • Contributed to the re­design of the online TV guide service with a JavaScript heavy front end.
Technologies: YUI, jQuery, JavaScript, Ella CMS, Django, Python

.NET Developer

2010 - 2011
  • Contributed to the development of the main company's SW product, a Silverlight-based back­-office system, and took ownership of one of its modules.
  • Implemented new features and fixed dozens of bugs in another product, a web-based issue tracking system.
Technologies: JavaScript, Microsoft Silverlight, Microsoft SQL Server, ASP.NET, C#

.NET Developer

2008 - 2010
Data System Solutions s.r.o.
  • Collaborated to maintain and enhance the desktop client CRM for pharma industry and sales representatives.
  • Developed the CRM's web client. Implemented new features and reports.
  • Designed and created a monitoring tool for internal usage.
Technologies: XSLT, SQL Server Reporting Services (SSRS), Microsoft SQL Server, ASP.NET, C#


Solo developer of an iOS client for a Dropbox-like service.


An iPad client for a SaaS startup solving media management and sharing. I was the main developer of the service's back-end and API.


An iPhone client for service to arrange hostesses, entertainers, and venues for customers’ events. I was the main developer of the service's back-end and API.

TV Guide

Online TV guide for one of the biggest Czech portals. (Czech)


Swift, Python, CSS, HTML, Objective-C, JavaScript, XSLT, Bash, Falcon, Java, C#, SQL, GraphQL


Cocoa Touch, Django, iOS SDK, Django REST Framework, Bootstrap, ASP.NET, Core Data, Cocoa, Bootstrap 3, Redux, AFNetworking, Flask, Tailwind CSS


Backbone.js, Underscore.js, jQuery, REST APIs, YUI, Alamofire, ReportLab, CocoaPods, Handlebars, React, Fabric, Tastypie, Marionette.js, Mypy, OpenAPI, SQLAlchemy


Xcode, Git, PyCharm, Celery, Microsoft Silverlight, Sentry, GitLab, Fastlane, Sublime Text, Terraform, Graphene, React Apollo


Redis, PostgreSQL, Microsoft SQL Server, SQL Server Reporting Services (SSRS), Datadog, MongoDB, Realm, Memcached, MySQL


REST, Agile Software Development, Scrum


Raspberry Pi, Docker, MacOS, iOS, Amazon Web Services (AWS), Visual Studio Code (VS Code)


Ella CMS, Koala

2004 - 2007

Bachelor's Degree in Computer Science

Charles University - Prague


Neural Networks and Deep Learning

Deeplearning.ai | via Coursera


Programming Languages, Part B

University of Washington | via Coursera


Programming Languages, Part A

University of Washington | via Coursera

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