Pavel is available for hire
Hire PavelPavel Werl
Verified Expert in Engineering
Software Developer
Brno, South Moravian Region, Czech Republic
Toptal member since February 2, 2017
Bio
Pavel has more than a decade of experience building software across multiple technology stacks, including the .NET platform, the JavaScript ecosystem, and the AWS cloud. He has worked on various projects—from building trading and portfolio management systems and designing and developing mobile apps, desktop apps, and websites to migrating legacy CRM systems to a modern serverless mobile-first single-page application.
Portfolio
General Systems Corporation
Amazon Web Services (AWS), Scrum, Agile Software Development, Jira...
Simulacrum Research a.s.
Finance, Financial Markets, Windows, Microsoft Excel, Capital Markets...
Stewardship Technology
BouncyCastle, SQL CLR, Microsoft SQL Server, T-SQL (Transact-SQL), .NET, C#...
Experience
Availability
Part-time
Preferred Environment
Windows, Visual Studio Code (VS Code), Amazon Web Services (AWS), MacOS, TypeScript, Node.js, .NET, Angular, SQL, C#
The most amazing...
...thing I've built was IRC-based covert remote control software written in C++. At that time I was only 15 years old.
Work Experience
Tech Lead and Senior Software Developer
2017 - PRESENT
General Systems Corporation
- Built a brand-new iOS app that was featured in the Good Morning America TV show.
- Reimplemented a flagship legacy CRM system into a modern serverless mobile-first web single-page application.
- Developed and maintained a popular high-traffic website with millions of monthly visitors.
- Architected and developed a near real-time sync of warehouse data between several different systems.
- Created a used car valuation iOS/Android app from scratch for a leading US-based vehicle data analytics company.
- Performed extensive cloud development using many AWS services, such as AWS Lambda, SQS, DynamoDB, RDS, EC2, Cognito, IAM, and others.
- Led, mentored, and trained coworkers on multitude of projects, tech stacks, and tools. Worked in an Agile Scrum team.
- Saved significant money for the company by analyzing and optimizing AWS billing costs, as well as architecting AWS solutions in such a way as to minimize the costs.
- Built new REST APIs, a proprietary web tracking system, conversion prediction by machine learning, and third-party API integrations, among many others.
- Performed technical research, built proofs of concept, and architected solutions.
Technologies: Amazon Web Services (AWS), Scrum, Agile Software Development, Jira, Entity Framework Core, REST APIs, jQuery, Node.js, TypeScript, JavaScript, Cordova, Ionic, Angular, ASP.NET, Microsoft SQL Server, T-SQL (Transact-SQL), SQL, .NET Core, .NET, C#, C#.NET, HTML, CSS, Java, Elasticsearch, Dart, Flutter, Search Engine Optimization (SEO), Back-end Development, Front-end Development, Oracle PL/SQL, PL/SQL, Machine Learning, Windows, Multithreading, REST, Design, MySQL, Visual Studio, SQL Management Studio, ASP.NET Core, UI Design, Serverless Architecture, AWS Lambda, Algorithms, Full-stack Development, Cloud Computing, Git, Visual Studio Code (VS Code), MacOS, Amazon API Gateway, Amazon Simple Queue Service (SQS), Amazon Cognito, Oracle, AWS Cloud Architecture
Equity Analyst
2021 - 2021
Simulacrum Research a.s.
- Performed due diligence of a company going public via SPAC.
- Analyzed company management, financials, projected revenue, competition, and business plan.
- Identified potential company risks, opportunities, and regulatory hurdles.
Technologies: Finance, Financial Markets, Windows, Microsoft Excel, Capital Markets, Microsoft Office
Software Developer
2017 - 2017
Stewardship Technology
- Designed and implemented a cryptographic library to protect the company's sensitive data stored in SQL Server.
- Developed a key management system to securely manage and store encryption keys.
- Documented every possible usage scenario, which helped the client resolve issues during server maintenance and migration.
Technologies: BouncyCastle, SQL CLR, Microsoft SQL Server, T-SQL (Transact-SQL), .NET, C#, C#.NET, SQL, Cryptography, Windows, Visual Studio, SQL Management Studio, Git, Back-end Development
Application Developer
2016 - 2017
Generali Investments CEE
- Developed proprietary portfolio management and trading system used to manage billions of USD worth of assets.
- Worked closely with portfolio and risk management teams.
- Implemented ex-post and ex-ante regulatory, statutory, and contract investment limits.
- Rebuilt a system for a spread and zero curves construction.
- Created a new forex derivatives pricing system in cooperation with risk management.
- Corrected pricing algorithms for sinkable and floating bonds.
- Produced new financial reports for internal and external clients.
Technologies: Bloomberg, Visual Basic for Applications (VBA), Microsoft Excel, Windows Presentation Foundation (WPF), .NET, C#, T-SQL (Transact-SQL), SQL, C#.NET, Windows, Multithreading, Financial Markets, Visual Studio, SQL Management Studio, UI Design, Microsoft SQL Server, Design, Capital Markets, Finance, Microsoft Office, Front-end Development, Back-end Development, Algorithms, Full-stack Development, Desktop App Development, Windows Desktop Software
Founder | Developer
2006 - 2010
Creatonix
- Founded a software business while still in high school.
- Developed two utilities for the Windows desktop platform.
- Handled development, customer support, licensing, and marketing.
- Created a custom website with integrated checkout.
- Developed utilities that were featured online and in a paper magazine in Germany.
Technologies: Adobe Photoshop, PHP, CSS, HTML, Visual Basic 6 (VB6), Visual Basic, Search Engine Optimization (SEO), Windows, Design, UI Design, JavaScript, Front-end Development, Back-end Development, Full-stack Development, Windows Desktop Software, Desktop App Development
Developer | Stakeholder
2005 - 2006
Dextrogames
- Developed and maintained a level editor for an indie puzzle game.
- Built a custom rendering engine just for the editor.
- Designed and implemented an easy-to-use visual point-and-click interface for authoring levels.
Technologies: Visual Basic 6 (VB6), Visual Basic, Windows, Design, UI Design, Desktop App Development, Windows Desktop Software
Experience
Portfolio Management and Trading System
An in-house system for portfolio management and trading on financial markets used to manage billions of USD worth of assets. The system was used by multiple departments within the company, such as portfolio managers, traders, risk managers, middle office, and back office.
I was part of a team responsible for the development and maintenance of the system. My most notable contribution was the development of new pricing algorithms and investment limits while working closely with portfolio and risk managers. My other work included the development of the user interface, producing financial reports, fixing numerous bugs, and others.
Built with T-SQL, C#, .NET, Windows Presentation Foundation (WPF).
I was part of a team responsible for the development and maintenance of the system. My most notable contribution was the development of new pricing algorithms and investment limits while working closely with portfolio and risk managers. My other work included the development of the user interface, producing financial reports, fixing numerous bugs, and others.
Built with T-SQL, C#, .NET, Windows Presentation Foundation (WPF).
Customer Relationship Management (CRM) System
A company's flagship product, the CRM system. I led the effort to reimplement the CRM system from a legacy codebase into a modern server-less application. I was responsible for all of the architectural work, the majority of the front-end and API development, and a portion of the back end.
Notable technologies include Angular, Node.js, Elasticsearch, AWS Lambda, AWS API Gateway, AWS SQS, AWS Cognito, Oracle, C#, and .NET.
Notable technologies include Angular, Node.js, Elasticsearch, AWS Lambda, AWS API Gateway, AWS SQS, AWS Cognito, Oracle, C#, and .NET.
Used Car Valuation iOS/Android Application
A Flutter/Dart application for iOS/Android, designed to estimate the value of used vehicles. I was the front-end developer and built the application alone from the ground up. I designed the application UI to follow the company's mockups and design language. The application includes an integrated VIN scanner, session management, real-time full-text search, and third-party API integrations. I developed the real-time VIN scanner from scratch, and the scanner is capable of recognizing barcode and character (OCR) VIN codes.
Legal Name Change App for iOS
An Ionic and Capacitor-based iOS app for changing legal names. The app scans the user's driver's license to extract AAMVA data, collects additional information from the user directly, charges his credit card, and forwards all of the collected information to the back end for processing. I built the app and the supporting API from the ground up, including integration with third-party services such as Stripe, Google Analytics, Facebook Analytics, and others. The app was featured in the Good Morning America TV show.
Website for Trail Tourism
A medium-sized website for trail tourism. Website users can search trails in the USA, explore them on the map, write reviews, upload images, etc. I was part of the team that developed the website, the supporting REST API, and the back-end database. The website has millions of monthly visitors and integrates with dozens of connected services like payment collection, analytics, advertising, etc. The REST API also supports iOS and Android apps.
Privacy Repairer
https://www.securilla.com/privacy-repairerPrivacy Repairer is a desktop application for optimizing Windows 10 privacy options. I built it from the ground up and carefully designed it to imitate Windows 10 look and feel. Privacy Repairer uses WMI, a Windows technology, to detect changes to the Windows configuration in real time and provide users live feedback. The application and all its dependencies are bundled into a single executable for easy deployment.
Mouse Gesture Recognition Software
I developed a mouse gesture recognition software for desktop Windows from the ground up.
The software lets users create arbitrary mouse gestures by simply drawing their mouse's gestures (symbols). Each gesture is associated with an executable file to run when the gesture is recognized. To invoke a gesture, simply hold down the right mouse button in any application and draw the symbol, and upon releasing the button, the proper file is executed.
A thumbnail is generated for every mouse gesture in the application dashboard for quick and easy management. Users can also utilize the inbuilt random mouse gesture generator.
Built with C#, .NET, WinForms, WPF.
The software lets users create arbitrary mouse gestures by simply drawing their mouse's gestures (symbols). Each gesture is associated with an executable file to run when the gesture is recognized. To invoke a gesture, simply hold down the right mouse button in any application and draw the symbol, and upon releasing the button, the proper file is executed.
A thumbnail is generated for every mouse gesture in the application dashboard for quick and easy management. Users can also utilize the inbuilt random mouse gesture generator.
Built with C#, .NET, WinForms, WPF.
Education
2012 - 2014
Master's Degree in Finance
Masaryk University - Brno, Czech Republic
2009 - 2012
Bachelor's Degree in Finance
Mendel University - Brno, Czech Republic
Certifications
OCTOBER 2019 - OCTOBER 2025
AWS Certified Solutions Architect — Professional
Amazon Web Services
SEPTEMBER 2019 - OCTOBER 2025
AWS Certified Solutions Architect Associate
AWS
SEPTEMBER 2017 - PRESENT
Machine Learning
Coursera
Skills
Libraries/APIs
jQuery, Node.js, REST APIs, BouncyCastle, Windows Forms (WinForms)
Tools
Visual Studio, Git, Amazon Simple Queue Service (SQS), Amazon Cognito, Microsoft Excel, Bloomberg, Adobe Photoshop, Jira, SQL Management Studio, C#.NET WinForms
Languages
JavaScript, SQL, C#, CSS, HTML, TypeScript, C#.NET, T-SQL (Transact-SQL), Visual Basic for Applications (VBA), Visual Basic 6 (VB6), PHP, Visual Basic, Java, Dart
Frameworks
.NET, Angular, .NET Core, Entity Framework Core, ASP.NET Core, ASP.NET, Ionic, Windows Presentation Foundation (WPF), Flutter
Paradigms
Serverless Architecture, UI Design, REST, Agile Software Development, Scrum, Search Engine Optimization (SEO), Desktop App Development
Platforms
Windows, Amazon Web Services (AWS), AWS Lambda, Visual Studio Code (VS Code), MacOS, iOS, Android, Umbraco, Oracle
Storage
MySQL, SQL CLR, Microsoft SQL Server, Elasticsearch, Oracle PL/SQL, PL/SQL, Oracle SQL
Other
Back-end Development, Front-end Development, Cloud Computing, AWS Certified Solution Architect, AWS Cloud Architecture, Cordova, Design, Financial Markets, Cryptography, Multithreading, Amazon API Gateway, Capital Markets, Finance, Microsoft Office, Machine Learning, Algorithms, Full-stack Development, Windows Desktop Software, OCR, Barcode Reader
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