Publication
C# vs. C++: What’s at the Core?
https://www.toptal.com/developers/c-sharp/c-sharp-vs-c-plus-plus
Jakiša is available for hire
Hire JakišaJakiša Tomić
Verified Expert in Engineering
Full-stack Developer
Zagreb, Croatia
Toptal member since November 13, 2019
Bio
Jakiša has 20 years of experience developing various types of apps for a range of operating systems. Most of his technical expertise is in C++ development, but he's also comfortable working with JavaScript, C#, and Java. As for environments, he knows the ins and outs of working with the Windows API, embedded programming, and distributed systems. He has a working knowledge of Linux/Unix systems, macOS, and mobile platforms like Android and iOS.
Portfolio
Toptal Client
C++20, .NET, C#, SQLite, CFAPI, C++/CLI
Toptal Client
HTML, JavaScript, CSS, OpenAI, OpenAI GPT-4 API, Fine-tuning
Toptal Client
Python, SQL, PostgreSQL, OpenAPI, OpenAI GPT-4 API, Semantic Kernel (SK)
Experience
- C++ - 15 years
- Full-stack - 14 years
- Concurrent Programming - 14 years
- HTML - 10 years
- Embedded Systems - 8 years
- C# - 8 years
- Linux - 4 years
- Python 3 - 4 years
Work Experience
Senior Backend Developer
2025 - 2026
Toptal Client
- Implemented a CFAPI (Cloud Filter API) service using C++, enabling cloud-based file system integration on Windows.
- Integrated SQLite for local data storage and management within the service.
- Developed a C++/CLI layer to expose the service interface to .NET consumers.
Technologies: C++20, .NET, C#, SQLite, CFAPI, C++/CLI
Senior Full-stack Developer
2025 - 2025
Toptal Client
- Developed a website for scholarship applications, providing a streamlined platform for submission, tracking, and review.
- Fine-tuned an OpenAI model to generate personalized scholarship recommendations tailored to student profiles and eligibility criteria.
- Designed and implemented a database to support fine-tuned OpenAI scholarship recommendation models, enabling efficient storage of student profiles, eligibility criteria, and recommendation history.
Technologies: HTML, JavaScript, CSS, OpenAI, OpenAI GPT-4 API, Fine-tuning
Senior Software Engineer
2025 - 2025
Toptal Client
- Developed an agent-based system that empowered AI models to autonomously generate, validate, and integrate new database functions, enabling dynamic extension of system capabilities without manual intervention.
- Integrated tool calling for OpenAI GPT through Semantic Kernel, enabling the seamless orchestration of AI-driven function execution within the application.
- Developed a mechanism for function code serialization between Python and the SQL database, enabling storage, retrieval, and execution of dynamically generated functions across both environments.
- Refactored the Python codebase to improve readability, maintainability, and performance.
Technologies: Python, SQL, PostgreSQL, OpenAPI, OpenAI GPT-4 API, Semantic Kernel (SK)
C# Developer
2024 - 2025
Toptal Client
- Developed a multiple-paged configurable form using Razor that collected user input.
- Developed a small expression language used for customization of scoring the user input.
- Wrote a SQL database with backup-restore functionality via the website.
Technologies: C#, HTML, JavaScript, CSS, SQL, Razor, Data Integration, ASP.NET, Blazor
Windows Developer
2023 - 2023
Toptal Client
- Tested and diagnosed the issue with the existing software installation related to the Microsoft Access database connection.
- Wrote the script that installs an appropriate driver based on the existing operating system and Microsoft Access database version.
- Improved the error reporting to provide better diagnostics for possible future errors.
Technologies: Windows, Python, Networks, Back-end, Object-oriented Programming (OOP), Code Architecture, Code Review, Windows API, Win32 API, Full-stack Development, Low-level Programming
Full-stack Engineer
2022 - 2023
Toptal Client
- Wrote a Python test that prevents errors of orphaned documentation pages that cannot be accessed from the documentation tree. In case of such errors, they would be spotted immediately instead of after deployment.
- Maintained and improved existing Python extensions for the Sphynx documentation platform.
- Worked on Python and shell scripts for documentation localization, including pre-processing and post-processing of localized HTML files.
- Performed the integration of React-based API documentation into the existing, static documentation tree.
Technologies: Documentation, Python, HTML, JavaScript, Docker, Back-end, Azure, Web Applications, API Integration, Object-oriented Programming (OOP), Code Architecture, Code Review, DevOps, Amazon Web Services (AWS), Unit Testing, Databricks, Automation, AWS Cloud Architecture, GitHub API, CI/CD Pipelines, Full-stack Development, Plotly, Data Integration
Senior Full-stack Developer
2021 - 2022
Weframe
- Developed a platform-independent driver for Apple screen mirroring using C++.
- Built a platform-independent driver for Google screencast in C++.
- Created a JavaScript library for video annotations.
Technologies: C++, C++20, Python 3, JavaScript, Back-end, TypeScript, Front-end, Mobile, Web Audio, Videos, TCP/IP, WebSockets, API Integration, Object-oriented Programming (OOP), Distributed Software, Code Architecture, Bootstrap, ARM, Unit Testing, Video Streaming, C#.NET, Software Architecture, Windows API, Win32 API, GitHub API, OAuth, WebRTC, Full-stack Development
C++ Developer
2021 - 2021
Toptal Client
- Developed a Windows Kernel driver for net filtering using C#.
- Wrote critical filtering code in C++ using native Windows API.
- Created the code that can be run both in the user space and kernel space to provide the client with a convenient testing environment.
Technologies: C++, Windows Kernel Drivers, Networks, C#, Back-end, Object-oriented Programming (OOP), Code Architecture, Code Review, Kernel, Windows Driver Kit (WDK), Unit Testing, Full-stack Development, Windows Kernel Debugging (WKD), Low-level Programming
C++ Developer
2020 - 2021
Toptal Client
- Wrote wrappers for connectors to various database engines in C++.
- Wrote functional tests in Python to catch the most common database errors in advance.
- Solved various multi-threading issues with existing database connectors.
Technologies: C++, Python, Back-end, Object-oriented Programming (OOP), Code Architecture, Code Review, Unit Testing, Full-stack Development
Go, React, and Android Developer
2020 - 2020
Toptal Client
- Wrote the back end for the fleet management software in Go.
- Developed innovative heuristic algorithms for traveling salesman problems with multiple simultaneous routes.
- Managed development of fleet management software in Go, Android, iOS, and React.
Technologies: Java, React Native, Android, React, HTML, CSS, Go, Docker, Back-end, Internet of Things (IoT), Cloud, Serverless, Architecture, Minimum Viable Product (MVP), Mobile Development, Front-end, Mobile, Web Applications, PostgreSQL, Figma, IoT Protocols, TCP/IP, Object-oriented Programming (OOP), Distributed Software, Code Architecture, Identity & Access Management (IAM), Code Review, Security, DevOps, Unit Testing, Mobile Applications, Google Cloud Platform (GCP), Connected Cars, Microservices, Software Architecture, Maps, Authentication, OAuth, Encryption, Mobile Apps, Full-stack Development, Networking, Sensor Data, Data Integration
C++ Developer
2020 - 2020
Toptal Client
- Improved the telemetry component, written in C++, by adding information needed for more useful results.
- Found and fixed various bugs in the existing C++ software.
- Wrote unit tests using Google Test framework for automated testing of the back-end components.
Technologies: C++, C++11, C++14, Subversion (SVN), Google Test, CMake, Jenkins, Back-end, Object-oriented Programming (OOP), Code Architecture, Code Review, Amazon Web Services (AWS), Unit Testing, AWS Cloud Architecture, CI/CD Pipelines, Full-stack Development, Data Integration
Software Developer
2019 - 2019
think-cell
- Developed a PowerPoint plugin for chart representation, using C++.
- Fixed issues related to Windows API messages using C++.
- Solved portability issues caused by discrepancies between Windows and macOS versions of Microsoft Office.
Technologies: Windows, Git, Functional Programming, Front-end Development, C++17, C++, Office Add-ins, Front-end, API Integration, Object-oriented Programming (OOP), COM, Code Architecture, Code Review, Windows API, Win32 API, Windows App Development, OAuth, Visual Basic, Full-stack Development
Software Engineer II
2017 - 2018
Microsoft
- Created Windows Mixed Reality scene hierarchy visualizations in various data formats, using C++.
- Refactored an existing C++ class hierarchy for the infrastructural components in Windows Mixed Reality.
- Worked on the component that transforms a design-time scene to a runtime scene (baking) using C++.
- Developed partial baking: the concept that allows only changed scene parts to be transformed into the runtime.
- Wrote a lightweight and maintainable XML creator in C++.
Technologies: Windows, Git, Concurrent Programming, C++17, Back-end Development, Mixed Reality (MR), C++, Qt, APIs, Back-end, API Integration, Object-oriented Programming (OOP), COM, Distributed Software, Code Architecture, Code Review, Unit Testing, Automation, Game Development, Windows API, Win32 API, Windows App Development, Windows Desktop, Encryption, Full-stack Development, Networking, ARM-based hardware
Software Developer
2016 - 2017
Arista Networks
- Participated in the creation of diagnostics components of network switches, using C++.
- Wrote unit tests for network switches using Python.
- Worked as a member of the DevOps team and monitored and maintained a continuous integration system.
- Found and fixed various bugs in existing unit tests.
- Enabled the Linux environment to use a visual code editor instead of traditional Vi/Emacs editors.
Technologies: Linux, Python 2, Embedded Software, Concurrent Programming, Embedded Systems, Back-end Development, Python, C++, Firmware, Embedded C, Embedded C++, System Integration, Embedded Development, Debian, Back-end, TCP/IP, Object-oriented Programming (OOP), Code Architecture, Code Review, DevOps, Embedded Linux, Unit Testing, Perforce, Encryption, CI/CD Pipelines, Full-stack Development, Networking, Low-level Programming
Senior Software Developer | Project Manager | Co-owner
2011 - 2016
Vorbion d.o.o.
- Created the server-side part of the monitoring software for electronics production, using C#.
- Built an internet-of-things server in C# and Microsoft SQL.
- Wrote the specifications for a multi-purpose monitoring device.
- Adapted Raspberry Pi to be used as a bridge between server and Bluetooth LE devices (used C++).
- Developed a C++ back end for Nginx for the purpose of faster REST-full processing.
- Created my own object-based scripting language in C++ as a portable language for front-end mobile development.
- Wrote various smaller applications for third parties, using web technologies such as Knockout and Angular.
Technologies: Linux, Windows, HTML5, jQuery, Python 2, Python 3, AngularJS, Knockout (Knockout.js), Embedded Software, Microsoft SQL Server, iOS, Android, SQLite, Git, Parsers, Concurrent Programming, HTML, REST, Embedded Systems, Back-end Development, Full-stack, JavaScript, C++, C#, C, CSS, Node.js, Firmware, Embedded C, Embedded C++, OpenCV, GStreamer, Angular, TypeScript, .NET, OpenGL, Entity Framework, REST APIs, APIs, App Integration, Embedded Development, Debian, PHP, Embedded Hardware, Back-end, Internet of Things (IoT), Raspberry Pi, .NET Core, Cloud, Serverless, Architecture, Minimum Viable Product (MVP), Social Networks, Mobile Development, Front-end, Mobile, Web Applications, MySQL, Figma, IoT Protocols, TCP/IP, API Integration, Object-oriented Programming (OOP), Distributed Software, Code Architecture, Bootstrap, Identity & Access Management (IAM), Security, DevOps, Kernel, Embedded Linux, ARM, Unit Testing, Mobile Applications, Automation, Microservices, C#.NET, Software Architecture, Game Development, Windows API, Win32 API, Windows App Development, Windows Desktop, Authentication, OAuth, Encryption, Objective-C, Mobile Apps, Visual Basic, Full-stack Development, Networking, Board Support Packages, Sensor Data, ARM-based hardware, Low-level Programming, Data Integration, ASP.NET
Senior Software Developer
2004 - 2010
Mireo d.d.
- Created the component that gave the correct directions for a turn-by-turn navigation system, using C++.
- Built the component which matches GPS data with the road network, using C++.
- Created a localization system for both spoken and written turn-by-turn navigation directions in C++ and an own scripting language.
- Constructed a portable controls library, using C++.
- Developed a server-client system that enables remote calling of C# methods from the client-side Javascript.
- Implemented the correct grammar structure of spoken turn-by-turn directions in more than 30 spoken languages.
- Implemented a driver for GPS tracking device in Java.
- Developed the front-end part of four different turn-by-turn navigation software products.
- Wrote various utilities to speed-up development in the company.
- Led a four-member team for a year that developed a web-based fleet management system.
Technologies: Windows, Full-stack, Windows CE, jQuery, Embedded Software, Microsoft SQL Server, Xcode, Parsers, Concurrent Programming, HTML, Front-end Development, Embedded Systems, Back-end Development, Windows API, SQL, Java, JavaScript, C#, C++, CSS, .NET, App Integration, System Integration, APIs, Embedded Hardware, Back-end, Excel Add-ins, Visual Studio Tools for Office (VSTO), Web Scraping, Architecture, Minimum Viable Product (MVP), Mobile Development, Front-end, Mobile, Web Applications, TCP/IP, API Integration, Object-oriented Programming (OOP), COM, Distributed Software, Code Architecture, Identity & Access Management (IAM), DevOps, ARM, Mobile Applications, Automation, Microservices, C#.NET, Software Architecture, Scraping, Maps, Win32 API, Windows App Development, Windows Desktop, Authentication, Mobile Apps, Visual Basic, Full-stack Development, Networking, Sensor Data, ARM-based hardware, Low-level Programming, Data Integration, ASP.NET
Project History
Mireo via GPS
This is a type of navigation software, written in C++. The navigation sentences were assembled in a scripting language that I developed. I also created a matcher (the part that matches GPS location with road grid), advisor (the part that decides which advice will be given on each crossing), portable control library, and various other parts.
Mireo Fleet
Mireo Fleet is a type of fleet management software, written in C++ and C#. We also developed a later web-based version in JavaScript. I wrote drivers for particular tracking devices in C++, parts of dedicated client software in C#, and also led a team of junior web developers for the JavaScript part.
Mireo GElin
I created a showcase traffic map of Croatia, similar to Google Maps. I developed it in JavaScript and C# along with implementing my own API for remote function calling. I also developed both the server side and web application.
Universal Data Monitoring
I built a full internet-of-things solution for Vorbion. I developed the server-side in C#, the device software in C++ and Python, and the client application in C#. I also developed the server and device software.
Donkey Programming Language
https://github.com/jakisa/donkeyThis is a programming language that I developed in my spare time. It is a general-purpose object-oriented scripting language but its usage has been limited so far. It is feature-complete and has all main object-oriented features implemented.
Windows Mixed Reality
I worked on the virtual reality engine infrastructure team in Microsoft Dublin's office. I mostly focused on baking (conversion from the design-time scene to the runtime scene). It was entirely developed in C++.
Latency Analyzer (LANZ)
Arista LANZ is a type of software that analyzes latency in network switches. I worked on the protocol port on the newly developed hardware version. It was written in C++ and Python. The work was performed exclusively in Linux terminal.
Publication
Stork, Part 4: Implementing Statements and Wrapping Up
https://www.toptal.com/developers/c-plus-plus/stork-programming-statements-in-c-plus-plus
Publication
Stork, Part 3: Implementing Expressions and Variables
https://www.toptal.com/developers/c-plus-plus/implementing-expressions-variables-in-c-plus-plus
Publication
Stork, Part 2: Creating an Expression Parser
https://www.toptal.com/developers/c-plus-plus/creating-an-expression-parser-in-c-plus-plus
Publication
Stork: How to Make a Programming Language in C++
https://www.toptal.com/developers/c-plus-plus/creating-programming-language-in-c-plus-plus
Education
2000 - 2006
Master's Degree in Mathematics and Computer Science
University of Zagreb - Zagreb, Croatia
1995 - 2000
Technician's Diploma in Electrical Engineering
Ivan Mestrovic High School - Drnis, Croatia
Skills
Libraries/APIs
Windows API, Node.js, OpenGL, Entity Framework, REST APIs, React, Win32 API, WebRTC, jQuery, Web Audio, GitHub API, OpenAI API, OpenCV, OpenAPI
Tools
Visual Studio, Xcode, Git, Logic Pro, Visual Studio Tools for Office (VSTO), Windows Driver Kit (WDK), Plotly, Subversion (SVN), CMake, Jenkins, Figma, Perforce
Languages
Python, Go, C++, C++17, JavaScript, C#, Java, HTML5, HTML, Python 2, Python 3, PHP, Objective-C, C, CSS, Embedded C, Embedded C++, TypeScript, C#.NET, Visual Basic, SQL, Excel VBA, Delphi, C++11, C++14, C++20, C++/CLI
Frameworks
.NET, .NET Core, ASP.NET, AngularJS, Knockout (Knockout.js), GStreamer, Bootstrap, Blazor, Qt, Angular, Google Test, React Native, Razor
Paradigms
Concurrent Programming, REST, Mobile Development, Object-oriented Programming (OOP), Unit Testing, Automation, Microservices, Windows App Development, Functional Programming, DevOps
Platforms
Windows, Debian, Raspberry Pi, Mobile, Kernel, Embedded Linux, Windows Desktop, Linux, MacOS, Windows CE, Docker, Amazon Web Services (AWS), Android, iOS, Azure, Databricks, Google Cloud Platform (GCP)
Storage
MySQL, Microsoft SQL Server, SQLite, PostgreSQL, Data Integration
Other
Embedded Systems, Parsers, Front-end Development, Back-end Development, Full-stack, Embedded Software, Firmware, Data Engineering, Scripting, Reports, Office Add-ins, APIs, App Integration, Embedded Development, Back-end, Internet of Things (IoT), Cloud, Serverless, Web Scraping, Architecture, Minimum Viable Product (MVP), Social Networks, Front-end, Web Applications, IoT Protocols, TCP/IP, API Integration, COM, Distributed Software, Code Architecture, Identity & Access Management (IAM), Code Review, ARM, Mobile Applications, Software Architecture, Scraping, Encryption, Mobile Apps, CI/CD Pipelines, Full-stack Development, Networking, Sensor Data, ARM-based hardware, Low-level Programming, System Integration, Windows Kernel Drivers, Excel Add-ins, Videos, WebSockets, Security, Video Streaming, Maps, Authentication, OAuth, Windows Kernel Debugging (WKD), Board Support Packages, Data Science, Generative Pre-trained Transformer 4 (GPT-4), Mixed Reality (MR), Mathematics, Computer Science, Electrical Engineering, Documentation, Networks, Embedded Hardware, Connected Cars, AWS Cloud Architecture, Game Development, Machine Learning, OpenAI GPT-4 API, Semantic Kernel (SK), OpenAI, Fine-tuning, CFAPI
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