Luka Stojiljković
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Luka
Stojiljković

Software engineer in Belgrade. I lead teams and build complete systems, from banking platforms to LLM agents, and ship them with tests.

Experience and education

Experience

  1. AI in AEC

    May 2025 – Jan 2026 Software Developer

    An AI consulting startup for architecture, engineering and construction.

    • Built Neostack, a prototype web app that helps firms catalogue their software stack and licence usage.
    • Built AI in AEC Flow, an internal platform for time, task and revenue tracking.

  2. BANKA_2

    2025 – 2026 Team Lead

    Software Engineering capstone at RAF.

    • Led 25 students across backend, web, Android and DevOps, wrote the majority of the code and designed the Arbitro assistant.

Education

  1. School of Computing (RAF)

    2023 – 2026 BSc Computer Science

    Union University, Belgrade. Expected 2026.

  2. Faculty of Mathematics

    2018 – 2023 Computer Science studies

    University of Belgrade.

  3. Languages

    Serbian (native), English (full professional proficiency).

Selected work

BANKA_2

2025–2026 Team lead, Software Engineering capstone at RAF

An enterprise banking platform built by a 25-person team I led across backend, web, Android and infrastructure. I wrote most of the code and designed Arbitro, its LLM assistant.

Red is the path every request takes: in through the gateway, then on to banka-core or the trading service.

25
engineers on the team
4,413
backend tests, JUnit and Mockito
1,254
frontend tests in Vitest, plus a Cypress suite
Stack
Java 25, Spring Boot 4, PostgreSQL, React 19, Kotlin, Docker, Ollama

Backend Frontend Android Infrastructure

The services of BANKA_2. Point at or tap one to read what it does.

Stem Agent

2026 Applied AI

An LLM agent that specializes itself for a domain by evolving pipelines of typed tools, and keeps what works between sessions.

  • Every tool declares input and output types; pipelines that don't type-check can't run.
  • Six mutation operators with beam search; a MAP-Elites archive keeps the skill library diverse.
  • Runs locally on LM Studio with Gemma, with an external judge only when a key is set.

Python, LM Studio, Gemma, MAP-Elites

Source

The Nexus dashboard with today's agenda, upcoming tasks and exams. The Nexus dashboard in its night theme.

Nexus 3.0

2026 Desktop app

An offline workspace of forty-three modules, from tasks, notes, study and finance to offline Wikipedia and maps, a personal gallery and signed content packs, with an AI agent that runs locally and works in all of them. Your data never leaves your computer.

  • An on-device LLM agent (llama.cpp, open models from Hugging Face) that acts in every module through 207 typed tools. Each turn offers the tools that fit the open page and the model's context window, every change asks first, and answers cite your notes, packs and offline Wikipedia.
  • Local models stay under the user's control: an NLLB-200 translator covers 202 languages and can be loaded or ejected to release memory; the assistant exposes the same explicit memory controls.
  • Built for small models: tool calls decode under a grammar built from each tool's schema, reads run in parallel and writes one at a time, and an answer that claims a change that never happened is asked again. An eval suite scores each model in English and Serbian.
  • Electron and React app for Windows, Linux and macOS with an encrypted SQLite store. Accounts can use a passcode or explicit device-convenience mode; Linux works without a keyring, while Private notes keep their own mandatory credential.
  • No online account and no server. Gallery stores personal pictures in encrypted local storage, and CI enforces the offline boundary and the limits on update, model and content-pack downloads.
  • Updates, models and content packs install only after their signatures and checksums verify.

TypeScript, React, Electron, llama.cpp, SQLCipher, Turborepo

Open source under Apache 2.0.

Download Website Source

Windows apps

Four native apps, each released with an installer, CI and its own website.

Refreshify's home page with the Run all action and the state of this PC. Refreshify's home page in the dark theme.

Refreshify 2.0

Cleans up, repairs and updates Windows with the tools Windows already has, without a terminal window.

  • Runs 16 built-in tools in an order that avoids known failures, after creating a restore point.
  • Recognizes 15 common failures and fixes the ones it safely can.
  • Turns a failed step into a report for an AI assistant, with personal paths hidden.
  • Checks the PC's health in plain words and shows where the disk space went.

C#, .NET, WinUI 3, Windows App SDK

Download Website Source

Pwrschdlr counting down to a shutdown. Pwrschdlr counting down to a shutdown, in the dark theme.

Pwrschdlr 2.0

A power scheduler, minus the vowels. Shuts down, restarts, sleeps, hibernates or signs out when a timer runs out.

  • A one-time Task Scheduler task keeps the timer when the app is closed; nothing stays running.
  • An always-on-top warning before the end lets you cancel or postpone.
  • A timer missed while the PC was off never fires late.
  • Can also wait for downloads to finish, an app to close or the PC to sit idle, or repeat on chosen days.

C#, .NET, WinUI 3, Task Scheduler, Inno Setup

Download Website Source

PermaDel with four files on the shred list and three overwrite passes. PermaDel's shred list in the dark theme.

PermaDel 2.0

Securely shreds files and folders on Windows so recovery tools can't bring them back.

  • File Explorer context menu and an optional Windows Hello check before shredding.
  • Overwrites alternate data streams, flushes every pass to disk and refuses unsafe targets.
  • Forensic tests scan a raw disk image to prove the data is gone.
  • Wipes a drive's free space and removes metadata from photos and Office files.

C#, .NET, WinUI 3, C++, Inno Setup

Download Website Source

PerfWindow showing load, temperatures and power for the CPU, GPUs, memory, network, battery and disks. PerfWindow's dashboard in the dark theme.

PerfWindow 2.1

Real-time hardware monitor for Windows: load, temperatures, power and lifetime data for every component, in a window or a terminal.

  • Rust and egui dashboard fed by a .NET sensor service built on LibreHardwareMonitor, over a named pipe.
  • New in 2.1: perfwindow-cli, a live dashboard in the terminal that gives scripts and AI agents the readings as text or JSON.
  • The service starts on demand and exits with the window, and the installer handles the signed PawnIO driver and elevation.
  • Scales to fit any window, turns see-through, or shrinks to a one-line strip over the top of the screen.

Rust, egui, ratatui, C#, .NET 8, Inno Setup

Download Website Source

More projects

Machine learning and AI

  • Serbian real-time speech recognition

    A hybrid voice-activity detector feeding a published Wav2Vec2 XLS-R checkpoint, with live Cyrillic output. Group project.

    PyTorch, Hugging Face, WebRTC VAD
  • Multi-agent research assistant

    Six local ReAct agents that define terms, synthesize papers from arXiv and Semantic Scholar, and compile LaTeX reports. Group project.

    Python, LM Studio, ReAct
  • PetFinder adoption prediction

    Seven PyTorch architectures on tabular data and shelter photos. The smallest fusion network beat an 11M-parameter ResNet.

    PyTorch, ResNet18, multimodal fusion
  • Neural network from scratch

    Dense layers, manual backpropagation, Adam and a fused softmax cross-entropy in pure NumPy, trained on MNIST.

    NumPy
  • Word2Vec

    CBOW with negative sampling in pure NumPy, trained on the text of White Fang.

    NumPy
  • Classical ML from scratch

    Polynomial and ridge regression, k-NN on Iris and multinomial Naive Bayes on disaster tweets.

    NumPy, PyTorch
  • Titanic and self-driving CNN

    A from-scratch decision tree and network on Titanic, plus a behavioural-cloning CNN that drives the Udacity simulator.

    TensorFlow, Keras, OpenCV
  • Scene classification: CNN vs AlexNet

    A CNN trained from scratch against AlexNet transfer learning on six scene classes.

    MATLAB
  • Genetic algorithm, Lévi N.13

    Binary genetic algorithm minimizing a benchmark function with many local minima.

    NumPy

Systems and algorithms

Image processing

Android

  • NFCard

    Turns a phone into a tappable business card with NFC host-card emulation, with Nearby Connections for larger payloads.

    Kotlin, Jetpack Compose, Hilt, Room
  • Pomodoro, Calculator, Age in Minutes

    First Android apps, in Java and Kotlin.

    Android SDK

Stack

AI and ML
PyTorch, TensorFlow, scikit-learn, Hugging Face, Ollama, LM Studio, RAG, tool calling
Languages
Java, Kotlin, Python, TypeScript, C#, C++, Rust, SQL
Backend
Spring Boot, Spring Security, JPA/Hibernate, REST, SSE, FastAPI
Frontend and mobile
React 19, Vite, Tailwind CSS, Zod, Jetpack Compose, Hilt, Room
Data
PostgreSQL, MySQL, Oracle, SQLite/SQLCipher, Supabase, ChromaDB
Testing
JUnit 5, Mockito, Vitest, Cypress, xUnit
Desktop and systems
WinUI 3, Windows App SDK, Electron, egui, Inno Setup
DevOps
Docker, Docker Compose, Kubernetes manifests, GitHub Actions, nginx