Tomislav Peharda, Developer in Varaždin, Croatia
Tomislav is available for hire
Hire Tomislav

Tomislav Peharda

Verified Expert  in Engineering

Message Queues Developer

Location
Varaždin, Croatia
Toptal Member Since
January 16, 2019

The two great loves of Tomislav's life are research and tech, which is why he particularly relishes facing new challenges—he gets to deep dive into both when formulating the perfect solution. He's experienced in various areas of computer science to provide quality solutions in web (his primary focus) and desktop app development, as well as penetration testing, reverse engineering, machine learning, and algorithmic problems.

Portfolio

Morgan & Morgan
Scikit-learn, Python, Machine Learning, Data Processing
Volvo R&D Center - Main
Node.js, JavaScript, GraphQL, TypeScript, Git, Azure, Amazon Web Services (AWS)
HiredScore
TypeScript, Node.js, Jest, NestJS

Experience

Availability

Full-time

Preferred Environment

Visual Studio Code (VS Code)

The most amazing...

...app I have built is a Google maps-like geospatial viewer of San Francisco in 2D and 3D, which enables a high level of interactivity for labeling purposes.

Work Experience

Machine Learning Engineer

2023 - PRESENT
Morgan & Morgan
  • Led efforts in setting up scalable processing pipelines for the construction of ML training datasets.
  • Analyzed datasets to identify patterns for curating ML model training processes.
  • Developed a deep learning-based regression model to predict the legal matter's dollar value.
  • Worked on a tool to find similar legal matters to the anchor matter.
Technologies: Scikit-learn, Python, Machine Learning, Data Processing

Senior Software Engineer

2022 - 2023
Volvo R&D Center - Main
  • Worked on an online booking service that matches clients with the ideal dealership.
  • Optimized various workflows in the booking service to enable more performant operations.
  • Integrated booking tooling with various US and European markets required working with third-party APIs.
Technologies: Node.js, JavaScript, GraphQL, TypeScript, Git, Azure, Amazon Web Services (AWS)

Senior Software Engineer

2021 - 2022
HiredScore
  • Developed a Nest.js-based framework that abstracts complex concepts of the technology making it easy to start up and configure an HTTP server.
  • Assisted in migrating existing Python-based microservices to Node.js technology using a developed framework.
  • Collaborated with the internal team on collecting requirements, designing architecture, and leading the onboarding of teams.
  • Contributed to writing thorough documentation as well as the introduction of a test environment that tests the framework interfaces.
Technologies: TypeScript, Node.js, Jest, NestJS

Senior Full-stack Software Engineer

2021 - 2022
Labelbox
  • Led initial efforts in designing and implementing a machine learning model analysis tool, giving users insight into what they can do to improve their models.
  • Worked on a data analysis tool to support users in filtering a large amount of data (millions of records) by various criteria.
  • Contributed to data pipelines to import large labels into the system for labeling purposes.
  • Created various asynchronous task processors to optimize data throughput in the corresponding services.
  • Collaborated on previewing GeoJSON labels on top of different data types.
  • Worked on similarity search functionality that works with billions of assets.
Technologies: GraphQL, React, Python, Node.js, Data Pipelines, Message Queues, PostgreSQL, Elasticsearch, SDKs, Google Cloud Platform (GCP)

Full-stack Software Engineer

2019 - 2021
Leading Autonomous Vehicle Company
  • Worked on a 2D satellite view to enable tools for labeling geospatial data that enabled autonomous vehicles to navigate safely through space.
  • Created various labeling tools to support different feature use cases (lanes, crossroads, etc.).
  • Worked on a 3D view to enable labeling tools for traffic lights and traffic signs, as altitude is significant for these features. The autonomous vehicle can expect where the traffic light or traffic sign should be in space.
  • Collaborated on developing the labeling workflows to accommodate the labeling team with all the necessary functionalities to produce quality geospatial labels.
  • Worked on a tool to track the autonomous vehicle ride metrics to enable insights into the quality of each ride (number of hard-breaking events, number of driver interventions, etc.).
Technologies: GIS, Mapbox, RxJS, Test-driven Development (TDD), Go, REST APIs, PostGIS, PostgreSQL, TypeScript, Node.js, React, JavaScript

Senior Software Engineer

2018 - 2019
Simplifeye
  • Developed a web application that integrates with desktop dental management systems offering their functionalities online.
  • Led a team of five people responsible for integrating patient details, like procedures, personal data, etc., with payments.
  • Worked on introducing an SSO system that connected several applications under the same authentication protocols.
  • Optimized data sync flows by introducing reactive clearing and caching systems, proper throttling mechanisms, and priority queues.
Technologies: Node.js, Redis, TypeScript, PostgreSQL

Full-stack Web Developer

2017 - 2018
GR DIGITAL
  • Developed several game plugins and web applications that use React.js (Redux) and Vue.js (Vuex, Nuxt) on the front end and Node.js on the back end.
  • Built a game add-on in Lua that extends a game plugin functionality.
  • Developed extensions in C# to increase performance and override JavaScript limitations on a platform on top of which game plugins are built.
  • Constructed web applications in PHP (WordPress, WooCommerce, and Visual Composer).
  • Styled several web applications in HTML, CSS, and Sass (styled components) that also included patterns of templating.
  • Developed functional programming, ES6 (Babel), Webpack, Flow, Linters, NPM, and more.
  • Configured and administered server (Unix), setting up the deployment process (Naught and PM2).
Technologies: REST APIs, Socket.IO, Flow, GraphQL, MongoDB, MySQL, C#, Lua, WordPress, PHP, Node.js, Vue, React, JavaScript

Web Developer

2014 - 2015
Xfire
  • Coded a universal PHP-based algorithm that would report a game match stats to a tournament platform (Xfire) once a corresponding match has been found/finished based on a user's game ID.
  • Supported a number of games with the above algorithm including Heroes of Newerth (HoN), SMITE, StarCraft II: Wings of Liberty (SC2), World of Tanks (WoT), and League of Legends (LoL).
  • Developed a CSGO match supervisor/watcher which would report detailed match stats including a player kills, deaths, assists and so on to the Xfire tournament platform in real time.
  • Implemented a Java-based match supervisor/watcher which also took care of the warm-up/ready-up period, time-outs, disallowing unwanted players, and more.
Technologies: REST APIs, Sockets, Algorithms, Java, PHP

Highly Scalable Similarity Search

I worked on a project focused on developing a similarity search tool to handle millions of data points. The task involved creating an innovative solution for users to query data and find similarities using anchor assets or textual queries.

The challenge was creating a tool to manage vast data while providing accurate search results efficiently.

Leveraging my skills in Node.js, Machine Learning, GraphQL, and Elasticsearch, I contributed to the design of this semantic search tool. I utilized lightweight technologies, ML algorithms, and search optimization algorithms to ensure the tool could handle the data load and provide accurate results.

This tool has significantly improved data querying speed and accuracy, providing users a more streamlined and effective way to find similar data points.

Microservice to Support Structured and Unstructured Assets

My team and I worked on a new microservice designed to support the processing and storing of billions of structured and unstructured assets. This involved the creation of an ETL pipeline, API, and several SQL and NoSQL storages to enhance data querying and search capabilities.

Our primary objective was to design a system capable of handling high-volume data efficiently. We aimed to minimize processing time while maximizing search speed and flexibility in data querying.

The impact of our efforts was significant, resulting in a scalable, performant service capable of efficiently processing and storing billions of assets. This increased data availability and introduced new ways of querying data, significantly improving search capabilities.

Framework for Quick Bootstrap of Node.js Microservices

A project to migrate their existing Python microservices to Node.js architecture. The key focus was to develop a Nest.js-based framework that abstracts the complexities of the NestJs framework, tailored to align with the client's requirements.

The challenge was in the migration and creation of a simplified yet robust Node.js architecture from existing Python microservices without disrupting the client's operations. The company had a framework for bootstrapping Python applications and wanted a framework similar to Node.js.

I led the development of a Nest.js-based framework that simplified the complexities of the Nest.js framework. The client has successfully migrated a couple of their Python microservices to Node.js using the developed framework.

Finding Similar Legal Matters via AI

As a machine learning engineer, I utilized AI to optimize the efficiency of legal case analyses by identifying similar legal matters.

The project aimed to simplify the complex and time-consuming process of case comparison to better predict the potential outcomes of ongoing legal matters.

In this project, my team and I developed innovative weighting logic for each case component. I utilized AI, Python, Machine Learning, and TensorFlow skills to employ cosine similarity techniques for case identification.
Introducing this AI-based system significantly improved the efficiency and accuracy of legal case analysis. This not only streamlined the law firm's operations but also enhanced the decision-making process for attorneys, leading to a profound positive impact on the firm's overall workflow.

Plugins & Modifications for Gameplay

This project involved the development of plugins and modifications to extend the gameplay of popular video games like CSGO, WoW, PUBG, and more. This was accomplished by reading game process memory and providing additional information to the user.

As a full-stack developer, I leveraged my skills in reverse engineering, data visualization, Lua, Redux, Docker, React, Node.js, and JavaScript to develop custom plugins and modifications that improved the player game experience.

This project significantly enhanced the overall gaming experience, leading to increased user engagement and satisfaction. The additional information provided by the plugins and modifications allowed users to get more out of their gaming experience.

AI-powered Pitch Deck Builder

In the venture capital industry, the team at Growth Warrior Capital and I developed an AI-powered pitch deck builder. The core objective was to elevate and improve user responses to align better with industry standards using AI.

The main challenge was that user responses often lacked the necessary quality and adherence to industry standards, which led to ineffective pitch decks.

As a deep learning engineer, I utilized my Python, AI, machine learning, NLP, GPT/OpenAI, and data modeling skills. I contributed to developing AI features that validated user inputs, provided constructive feedback, generated improved examples, and educated users on why these examples were superior.

The result was a significant enhancement in the quality of user responses, leading to more effective and industry-compliant pitch decks, which, in turn, helped users secure more funding opportunities.

Autonomous Vehicle Rides Metrics Dashboard

With my team, I worked on a dashboard providing insights into metrics of autonomous vehicle rides, spotlighting areas for improvement.

The key challenge was to create a comprehensive system that would effectively analyze and present ride data to identify improvement areas.

This dashboard not only eased the data interpretation process but also provided valuable feedback, leading to significant improvements in the autonomous vehicles' performance.

ML Model Analysis Tooling

I led the design and development of a robust tool to analyze ML models. This tool was designed to delve into datasets and enhance ML model accuracy by providing insights into what cases the model might not be capable of predicting so well.

I developed a solution by using my skills in Artificial Intelligence (AI), Node.js, React, GraphQL, Systems Architecture, and PostgreSQL. I led the project, conceptualizing and executing the development of a tool to analyze ML models by assessing datasets.

The tool helped numerous enterprise consumers analyze their ML models, enhancing performance more efficiently. This included the application of different software engineering and ML engineering algorithms (such as TSNe, similarity search, etc.) to gain insights into the dataset.

Prediction of Legal Matter $ Value

This project involved developing a predictive model to estimate the dollar value of a legal matter. As a deep learning engineer, my role was pivotal in leveraging data science and engineering techniques to provide attorneys with a tool to assess potential case value.

The main challenge was to quantify the potential value of a legal matter, a task traditionally dependent on subjective human judgment.

I used my Python, AI, machine learning, NLP, data pipelines, and data analysis skills to create and test various traditional machine learning and deep learning algorithms. The goal was to design a system capable of making accurate predictions based on historical and contextual data.

The result of this ongoing project is a sophisticated predictive tool that reduces uncertainty and enables more informed decision-making in the realm of legal affairs.

Application for Providing Better Financial Security

As a data scientist, I worked on the application for providing better financial security for lower-income US citizens. The recommendations were given based on the various characteristics of an individual. As part of my role, I worked on the budgeting features such as scoring an individual's current financial situation, forecasting expenses, analysis of transactions, and more.

Investors Social Network

I worked on a social network for investors to enable them to share potential opportunities where they might collaborate. The network was Twitter-like, where users could share updates with various types of content. Users were provided with tools to personalize their profiles and provide insight into their background and the opportunities of their interest. The work also included a live messaging system.

Improving Data Quality by Curating Search

A video content marketing company engaged me to employ my skills as a data scientist in improving the quality of their video content review process. I achieved this by analyzing their extensive video media database using various Machine Learning and statistical methods.

The client had a vast amount of video media data, along with various metadata that had been reviewed over time. The challenge was figuring out how to use this data to enhance the quality of to-be-reviewed video content.

As a data scientist, I employed various skills to analyze the dataset. This analysis aimed to help the company better target what video content to focus on.

By leveraging AI and machine learning, the client could now prioritize their video content based on the insights derived from the data analysis, thus leading to an improvement in their overall video content quality.

Online Software for Dental Practices

https://simplifeye.co/
I worked on the payment features of online software for dental practices. The dental practices would use available desktop software to track patients and treatments. However, these applications had no payment integration or web interface. As part of the project, I worked on functionalities for the web application connected to the desktop application that enabled processing the patient treatments end-to-end.

Children Content Recommender

I worked on a pipeline based on manually labeled and reviewed YouTube videos and would attempt to find similar videos and channels through the construction of queries that targeted titles and keywords. A user would select various criteria to generate the list of already reviewed videos and use data from these videos to generate search queries.

Going further, YouTube would return relevant videos and channels based on the search query. However, the results might contain outliers; thus, the second part of the pipeline was to verify the quality of the returned analysis, which included the analysis of metadata through NLP techniques.

FOI AI Lab

Acted as a member of the Faculty of Organization of the Varaždin artificial intelligence laboratory. As part of the laboratory work, I collaborated on writing scientific papers on AI, wrote coding snippets, and was engaged in a project that focused on developing an orchestration platform to support multi-agent systems.

Tool to Build Internal Applications

https://www.superblocks.com/
I worked on a tool that enables building simple internal applications, mainly targeting analytic tools. Users would be able to construct the UI the way they want within the boundaries of the components provided. Users could connect their applications to data sources such as Snowflake, MySQL, etc.

Analytics Tool for Measuring Adequate Audience for Medicine Trials

https://clariness.com/
I worked on a project that provides insight to an adequate audience for medicine trials based on the survey data collected from millions of people. The surveys contain questions about an individual's health, which were then used for querying based on various criteria. The criteria could be anything from demographic and geographic to health conditions. The pharmacies would then get insight into what percentage of people are adequate for trials and may invite them for the experiments.

Intrusion Detection System (Machine Learning)

For my master's thesis, I have developed an intrusion detection system—a neural network (model) that inspects network traffic requests in order to determine whether a request is an intrusion or a valid request (the output of the model is a class of an intrusion).

The model is developed in TensorFlow, and it utilizes a Random Forest concept to minimize the number of attributes needed for the computation. It is based on the KDD1999 dataset. Different methods, utilities, and metrics have been used to examine the dataset and provide the most accurate solution.

In my thesis paper, I've used various data science approaches to examine the quality and diversity of the KDD1999 dataset. I also have shown how different neural network configurations (number of layers, number of neurons, activation function, regularization, and so on) impact output precision.

Technologies: Pandas, NumPy, Python, TensorFlow (Keras API), Random Forest

Freelance Projects

I've worked on various projects for a range of clients including a law firm, a logistics company, and a gym.

Law Firm
The purpose of this web application (which also worked on a phone) was to enable the law firm to schedule and track appointments. Each appointment would have a detailed history of events. A user was also able to set notifications for each appointment.

Logistics Company
This web application was used to track drivers, trucks, trailers, destinations, and the like, however, the primary focus of the app was to have a weekly preview of an each user's schedule on a dashboard that is also highly interactive thus simplified the process of creating weekly schedules at the organizational level.

Gym
For this client, I built a web app that was meant to be used to track each user's subscriptions. A gym would have an RFID reader at the entrance requiring each user to scan their subscription card. That way, the owner would, in real-time, have access to the number of users at the gym — seeing whether any of them has not yet paid their subscription or such. The application also implemented various analytics previews.

Technologies: PHP, HTML, CSS, JavaScript, MySQL, jQuery, Bootstrap

Reverse-engineering Games

I've also reverse-engineered games with the Cheat engine, x96dbg, IDA disassembler, and developed both internal and external modifications in C# and C++. A strong knowledge base of x86 architecture and Assembly was the main priority.

Some of the main activities in the process are: analyzing and finding proper memory addresses, examining the Assembly code and making changes that would affect the game behavior, developing modifications that override memory locations and also invoke game functions in order to achieve the desired functionality, bypassing basic security mechanisms (some games would detect if the memory location value gets changed externally, other security mechanisms include updating multiple memory locations with the same value).

zPAM and ServerBot for CoD2

I developed an open-source modification in C/C++ for CoD2 to improve their competitive gameplay which was officially used in every game league that supported CoD2 (it is estimated that around 20,000 players used the modification). With the introduction of the modification, the game activity on a monthly basis was largely increased.

ServerBot was a functionality (or even a protocol) within the modification to enable a web application to listen to the server events in real-time and then preview them. The web application that I've built to make use of ServerBot was able to listen to 5 game servers simultaneously with ability to preview the events in real-time or with a delay.

Mobile Games and Applications

During my mobile development journey, I created a cross-platform application for storing user credentials on a phone and use the credentials to automatically sign-in into web applications. The primary focus was put on application security and data encryption.

I've worked on a multiplayer (peer-to-peer) game that utilized match-making system support through a central server to enable players to find an opponent automatically (also, the central server was used to store a user's stats). Once an opponent has been found, the communication between users no longer went through the central server but sockets (peer-to-peer connection). TCP hole-punching was used for players to establish a connection.

Technologies: Java, Corona SDK, Lua, Hole Punching, MySQL, SQLite

JavaScript Components for a Market

For a JavaScript-based market, I developed highly customizable JavaScript components out of which also included WordPress support. The most successful app I've developed was a scheduler that read events from a JSON file. The component provided multiple language support and on a date click, it would preview all events for that date with location (Google Maps integration) and time.

The other two components I've worked on were a 3D item slider and a carousel. The focus of the 3D slider was on shopping items—the items would be rotating (in different manners) and on a click, information for the selected item would be shown (a user could define information themselves). The carousel had similar use-case as the 3D item slider, however, the entity of a focus was not shopping items but rather images (therefore, usage, animations provided and implementation were fairly different from the 3D item slider).

Technologies: JavaScript, jQuery, HTML, CSS, WordPress, JSON

Languages

JavaScript, HTML, CSS, Sass, ECMAScript (ES6), TypeScript, Java, C#, C++, PHP, GraphQL, Python, Go, Assembly, Lua, C#.NET, C, Snowflake

Frameworks

Express.js, NestJS, Swagger, Spring Boot, Bootstrap, JSF, OAuth 2, Jest, Redux

Libraries/APIs

REST APIs, React, Vue, Node.js, jQuery, jQuery UI, Three.js, WebGL, Sockets, RxJS, Slack API, TensorFlow, Socket.IO, Passport.js, Scikit-learn

Tools

Slack, Git, Sony Vegas, Adobe After Effects, Adobe Photoshop, Flow, Webpack, GIS, Visual Studio

Paradigms

Functional Programming, Penetration Testing, Agile, REST, Test-driven Development (TDD), Unit Testing, E2E Testing, Scrum, Testing, Agent-based Modeling, Good Clinical Practice (GCP), ETL

Platforms

Mapbox, Amazon Web Services (AWS), Unix, Docker, WordPress, Android, Google Cloud Platform (GCP), Visual Studio Code (VS Code), Azure

Storage

MySQL, MongoDB, PostgreSQL, PostGIS, SQLite, Elasticsearch, BigTable, Data Pipelines, Redis

Other

Algorithms, APIs, GitKraken, Reverse Engineering, System Administration, Discord Bots, Machine Learning, Message Bus, Message Queues, Data Structures, Mobile Apps, Planning, Deep Learning, Augmented Reality (AR), Multi-agent Systems, Statistics, Research, SDKs, Neural Networks, Natural Language Processing (NLP), Streaming, Artificial Intelligence (AI), GPT, Generative Pre-trained Transformers (GPT), Large Language Models (LLMs), Data Processing

2021 - 2023

PhD in Information Science

University of Zagreb, Faculty of Organization and Informatics - Varaždin, Croatia

2017 - 2019

Master's Degree in Information and Software Engineering

University of Zagreb, Faculty of Organization and Informatics - Varaždin, Croatia

2014 - 2017

Bachelor's Degree in Information Systems

University of Zagreb, Faculty of Organization and Informatics - Varaždin, Croatia

Collaboration That Works

How to Work with Toptal

Toptal matches you directly with global industry experts from our network in hours—not weeks or months.

1

Share your needs

Discuss your requirements and refine your scope in a call with a Toptal domain expert.
2

Choose your talent

Get a short list of expertly matched talent within 24 hours to review, interview, and choose from.
3

Start your risk-free talent trial

Work with your chosen talent on a trial basis for up to two weeks. Pay only if you decide to hire them.

Top talent is in high demand.

Start hiring