Davor Lovrić
Verified Expert in Engineering
Xamarin Developer
Zagreb, Croatia
Toptal member since October 21, 2013
Davor is an advocate of Agile methods, and he is typically involved in every project stage from planning and architecture to coding/testing. He easily transfers know-how to team peers, while thinking both strategically and out of the box.
Portfolio
Experience
- API Integration - 20 years
- Excel VBA - 20 years
- Microsoft SQL Server - 20 years
- C# - 15 years
- Cross-platform - 10 years
- Excel to MySQL - 10 years
- iOS - 10 years
- Android - 8 years
Preferred Environment
NetBeans, AppCode, XPath, Visual Studio, Blockchain, Blockchain Platforms, Cryptocurrency, Decentralized Exchanges (DEXs), Smart Contracts, Binance Smart Chain (BSC), Swaps, Aggregators
The most amazing...
...thing I've created is a multi-platform app builder supporting Android, iOS, Windows Phone, and Windows with same code base.
Work Experience
Senior Crypto Developer
Solidity Development Company
- Created an application (bot) that continually tracks Ethereum EVM-compatible blockchains for on-chain exchange rates and finds profitable arbitrages.
- Wrote highly optimized parametrized contracts in Huff (Assembly-like language for Ethereum contracts) for executing arbitrages. Optimized the contract for different blockchains.
- Integrated with Binance API for live monitoring exchange rates and comparing them with on-chain exchange rates.
- Represented coins and exchanges as graphs and optimized its analysis using Johnson's algorithm.
- Automated detection of non-functional tokens by running simulated conversions.
- Investigated regulations about using centralized exchanges from different jurisdictions.
- Wrote numerous phyton scripts for fetching and analyzing blockchain decentralized finance data.
- Packed solution as a group of Docker containers with different lifecycles and can be deployed as needed.
Senior Software Architect
Insolitus Vermis d.o.o.
- Implemented cloud-based APIs consumed by mobile applications with data stored in Azure MS SQL.
- Implemented cross-platform applications using Xamarin.
- Optimized and restructured MS SQL databases for better performance.
Senior Architect
Autonomous Call Agent
- Created a web platform that automates outreach calls.
- Worked on campaigns that are based on CSV files with phone numbers and additional data that are integrated into call scripts. For each outgoing call, a separate script was created and then used during the call to create new responses.
- Integrated different AI providers for logic (OpenAI), transcription (Deepgram), and speech generation (11labs).
Excel VBA Developer
Excel Developer
- Integrated Excel with Shopify for bidirectional sync through Shopify API.
- Used Excel data to create and update products and product versions automatically.
- Resized product images stored as local files by automating Photoshop before uploading to Shopify.
- Downloaded data about completed orders from Shopify and input it into an Excel table.
Developer
Solidity Development Company
- Developed an application that was sending transactions to contract communication with other contracts. It was essential to execute transactions on specific blocks, so gas expenses were high.
- Developed internal gas-saving through contract creation/destruction in the same way as standard GasTokens were implemented later.
- Used a unique trick to count deleted contracts without spending additional gas.
CEO | Developer
Insolitus Vermis d.o.o. – Chameleon 2
- Started working on Chameleon 2, a Xamarin-based framework for creating applications in C# for Android, iOS, Windows, and Windows Phone from the same codebase.
- Ensured basic operations (play sound, open file, etc.) were supported on all platforms.
- Supported the same operations on all platforms to remove the need for testing on mobile devices.
Excel Developer
Excel for Marketing Department
- Stored data about individual marketing agencies and channels in Excel. Each agency and channel required images of a specific size (different banners, full-page ads, and more).
- Used Excel VBA to match existing marketing materials with the agency's requirements and highlight missing materials.
- Used Excel VBA to make task lists for designers to create missing formats highlighting which agencies need them.
Developer
Excel as J2ME build automation
- Created an Excel file that was tracking different versions of J2ME applications. Each mobile phone needed a separate application.
- Built applications from Excel by integrating it with J2ME command line tools.
- Stored data about graphical content for applications in Excel and created custom images by automating Photoshop from Excel.
Freelance Developer
Zipato
- Rewrote and upgraded an Android application for smart home system called Zipato.
- Fixed existing bugs, added drag-n-drop support for reordering list items, and added support for RTSP streaming. RTSP streaming was done using FFmpeg and OpenGL ES to fetch, decode, and display camera streams.
CEO/Developer
Savršen Plan d.o.o. – Chameleon
- Created Chameleon, an iOS/Objective-C framework for creating simple applications using XML, with a goal to enable designers to create iOS applications without any programming knowledge.
- Created custom UI component SmartLabel, capable of displaying text in more than one color/font/size/style. All attributes can be defined in an XML-like syntax.
CEO/Developer
Savršen Plan d.o.o. – Cropper
- Created Cropper, an application for cropping photos in a customizable number of different aspect ratios with the ability to modify and preview all cropped versions while at same time reducing photo manipulation time to 1/6 of initial time.
CEO/Developer
Savršen Plan d.o.o. – J2ME Automated Build System
- Created an automated build system with photo content resizing and compression to meet different maximum application size limits on various J2ME devices.
Developer
Private Content-based Website CMS
- Developed a CMS from scratch using C#, ASP.NET, and MS SQL.
Project Manager
Omega Software d.o.o.
- Led a team of 12 developers in transition from Visual Basic to C#.
- Started the process of restructuring developed ERP system and introducing new development technologies while maintaining compatibility with an existing codebase.
- Directly worked on adapting the system to support data replication between tens of MS SQL servers.
Project Manager
Ve-mil d.o.o.
- Supported an existing ERP system based on MS SQL Server.
- Created an Excel+VBA reporting solution with automated data retrieval from MS SQL as a fix for the lack of reporting in existing ERP system.
- Created new ERP system using MS SQL Server and Borland C++ Builder.
Oracle Developer
Plus Plus d.o.o.
- Created insurance applications using Oracle tools.
Developer
Incendo d.o.o./VIPnet d.o.o
- Created a GSM network development tracking tool using MS SQL, MS Access, and Borland C++ Builder.
Developer
Filex d.o.o.
- Developed a computer game (presidential elections) in C++ for Apple Macintosh.
Education
B.Sc. Degree in Computer Engineering
Department of Mathematics, University of Zagreb - Zagreb, Croatia
Silver Medal Degree in Algorithmic programming
International Olympiad in Informatics - Netherlands
Skills
Libraries/APIs
REST APIs, Facebook API, API Development, PayPal API, FFmpeg
Tools
Amazon Elastic Container Service (ECS), Microsoft Visual Studio, AppCode, MSBuild, MySQL Workbench, Excel 2016, Microsoft Excel, Adobe Photoshop, GitHub, Trello, Eclipse IDE, Git, Microsoft Access, FileMaker Pro, Visual Studio, Adobe Illustrator, Asana, Excel 2010
Languages
VB, Swift, Java, C#, Objective-C, C, Solidity, Python, Excel VBA, Visual Basic for Applications (VBA), Visual Basic 6 (VB6), CSS, HTML, ASP.NET Razor, PHP, Transact-SQL (T-SQL), C++, Solidity Assembly, XML, XPath, JavaScript, SQL
Frameworks
.NET, Android SDK, ASP.NET, JNI, ASP.NET Core, Entity Framework Core
Paradigms
RESTful Development, REST, Refactoring, Inversion of Control (IoC), Agile Software Development, Unit Testing, Cross-platform, Dependency Injection, App Development, Model View Controller (MVC), Continuous Integration (CI)
Platforms
Azure, iOS, Android, Xamarin, Windows, Blockchain, Blockchain Platforms, Decentralized Exchanges (DEXs), NetBeans, Windows Phone, J2ME, Oracle
Storage
Databases, JSON, Amazon S3 (AWS S3), Microsoft SQL Server, SQL Server Management Studio (SSMS), MySQL Server, MySQL, Oracle PL/SQL
Other
APIs, Microsoft OneNote, Domain-driven Design (DDD), Excel to MySQL, Cryptocurrency, Smart Contracts, Binance Smart Chain (BSC), Swaps, Aggregators, Architecture, API Integration, CTO, Fractional CTO, Web Development, Trading Bots, Exchanges, Integration, Enterprise Resource Planning (ERP), User Interface (UI), Maps, GitFlow, Location Services, IIS, Artificial Intelligence (AI), Natural Language Processing (NLP), 4D, Computer Engineering, Huff, Arbitrage
How to Work with Toptal
Toptal matches you directly with global industry experts from our network in hours—not weeks or months.
Share your needs
Choose your talent
Start your risk-free talent trial
Top talent is in high demand.
Start hiring