Software Engineer and Researcher · Warsaw, Poland

Tomasz Jóźwik

Ruby on Rails, R&D and AI Engineering

Have a Rails, data or optimisation challenge? Let’s talk.

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What I do

I build production-grade software and research-driven solutions: from Ruby on Rails platforms, through R&D and optimisation projects, to AI and data-science experimentation workflows.

Currently:

  • Senior Ruby Developer at Measure Studio
  • Freelance engineer for Tiny House Listings
  • PhD candidate at the Military University of Technology

Experience

  1. – now

    Senior Ruby Developer Social-media analytics

    Measure Studio · remote

    Backend and data engineering for a social-media analytics platform used by media companies, brands and agencies. I design warehouse-style processing of per-post metrics across social networks (ingestion, transformation and aggregation pipelines) and keep it fast and correct at production scale.

    • Ruby on Rails
    • PostgreSQL
    • Data pipelines
    • Analytics

  2. – nowfreelance, B2B

    Freelance Software Engineer Real estate

    Tiny House Listings · remote

    Independent engineering for the leading tiny-house marketplace. End-to-end ownership of the Rails API, the Ember.js web app and the admin panel: new features, database and page-load performance, SEO, payments, CI/CD and hosting migrations.

    • Ruby on Rails
    • Ember.js
    • PostgreSQL
    • Cloudflare
    • CI/CD

  3. – 2 yrs 9 mos

    Ruby on Rails Tech Lead iGaming

    SOFTSWISS · Warsaw

    Led a backend team responsible for the technical side of regulatory compliance: adapting the platform to legal requirements across multiple jurisdictions. Owned architecture decisions and code-quality standards, coordinated delivery with other teams, and introduced structured incident response, code review and deployment-reliability practices.

    • Team leadership
    • Ruby on Rails
    • Architecture
    • Regulatory compliance

  4. – 2 yrs 6 mos

    Software Engineer & Team Lead Various industries

    Visuality · Warsaw

    Built Rails applications and APIs for English-speaking clients, making high-level architecture calls that balanced user needs with the client’s budget. Ran a Kubernetes-based infrastructure with CI/CD and owned the release lifecycle of hybrid iOS and Android apps. As team lead: task estimation, sprint planning, mentoring and code quality.

    • Ruby on Rails
    • Kubernetes
    • AWS
    • Hybrid mobile apps
    • Mentoring

  5. – 6 mos

    Software Engineering Intern Business processes

    Visuality · Warsaw

    Modelled the company’s business processes in BPMN to improve the internal flow of information, and worked on internal Rails applications running on AWS.

Core Expertise

  1. Ruby & Rails

    Production backends and distributed systems.

  2. R&D & Optimisation

    Simulation, emulation and experimental benchmarking.

  3. AI & Data

    Data pipelines, model evaluation and analytics engineering.

  4. Cloud Infrastructure

    AWS, Oracle Cloud, Kubernetes and Docker.

  5. Technical Leadership

    Cross-functional teams and reliable delivery.

Lab certificate

Finish all five experiments and download a PDF certificate with your name and results.

0 / 5 experiments completed

Toolbox

Languages
  • Ruby
  • Python
  • SQL
  • JavaScript
  • Bash
Frameworks
  • Ruby on Rails
  • Ember.js
  • Cordova (hybrid mobile)
Data
  • PostgreSQL
  • ClickHouse
  • MongoDB
  • Oracle Database
  • Data pipelines
  • Analytics
Cloud & ops
  • AWS
  • Oracle Cloud Infrastructure
  • Kubernetes
  • Docker
  • Heroku
  • Cloudflare
  • Linux
  • CI/CD
Optimisation
  • LP / MILP modelling
  • HiGHS
  • Heuristics
  • Simulation
  • Emulation
  • Benchmarking
AI
  • Whisper · speech-to-text
  • Local LLMs · FastFlowLM
  • LLM APIs · OpenRouter
  • LLMs in research
  • AI coding · Codex, Claude, Antigravity
Ways of working
  • Scrum
  • Kanban
  • BPMN
  • Code review
  • Incident response
  • Mentoring
Spoken
  • Polish · native
  • English · C1
  • Russian · B1

Research

Doctoral research

Energy-efficient routing in flying ad-hoc networks (FANETs)

PhD candidate in Information and Communication Technology at the Military University of Technology (WAT) in Warsaw, since October 2022.

UAVs in a flying ad-hoc network run on limited batteries, so the way traffic is routed directly affects how long the network stays in the air. I model unicast and multicast routing as linear and mixed-integer programmes (LP/MILP), benchmark heuristic and AI-based methods against exact solvers, and validate the results in simulation and emulation test-beds.

Before the PhD, at Warsaw University of Technology, I worked on energy-saving routing in data-centre networks.

Papers
4
Conferences
4
Since
2022

Publications

  1. 2025

    Determining energy-efficient routing paths in FANETs using LLM Sonar models

    Wyznaczenie energooszczędnych ścieżek routingu w sieciach FANET z wykorzystaniem modeli LLM Sonar

    T. Jóźwik · Przegląd Telekomunikacyjny – Wiadomości Telekomunikacyjne, 2025 (4) · doi:10.15199/59.2025.4.37

  2. 2024

    Optimisation model for energy-efficient multicast routing in FANETs

    Model optymalizacji dla energooszczędnego routingu multicast w sieciach FANET

    T. Jóźwik · XIII KNTWRE 2024 conference, Systemy rozpoznania i walki radioelektronicznej, Ołtarzew

  3. 2024

    Optimisation model for energy-efficient unicast routing in FANETs

    Model optymalizacji dla energooszczędnego routingu unicast w sieciach FANET

    T. Jóźwik · Przegląd Telekomunikacyjny – Wiadomości Telekomunikacyjne, 2024 (4) · doi:10.15199/59.2024.4.49

  4. 2023

    Router Activation Heuristics for Energy-Saving ECMP and Valiant Routing in Data Center Networks

    P. Arabas, T. Jóźwik, E. Niewiadomska-Szynkiewicz · Energies 16(10), 4136 · doi:10.3390/en16104136

Talks

  • Research 2025 · Gdynia

    Energy-Efficient Routing and Power Management in FANETs: A Comparative Analysis

    TransNav 2025, 16th International Conference on Marine Navigation and Safety of Sea Transportation · with K. Maślanka and J. Kelner

  • Research 2025 · Gdańsk

    Energy-efficient FANET routing with LLM Sonar models

    KRiT 2025, Konferencja Radiokomunikacji i Teleinformatyki

  • Ruby Jun 2024 · Malmö

    Mathematical Programming in Ruby

    Baltic Ruby 2024 · ▶ Watch the talk

  • Research 2024 · Ołtarzew

    Optimisation model for energy-efficient multicast routing in FANETs

    XIII KNTWRE 2024, Systemy rozpoznania i walki radioelektronicznej

  • Research 2024 · Poznań

    Optimisation model for energy-efficient unicast routing in FANETs

    KRiT 2024, Konferencja Radiokomunikacji i Teleinformatyki

  • Ruby Dec 2023 · Warsaw

    Mathematical Programming in Ruby

    Programowanie matematyczne w Ruby (original title, talk in Polish)

    Ruby Warsaw Meetup

…plus a few smaller Ruby community meetups.

Open source

  • 2020 · faker-ruby/faker

    Optional open compounds in Faker sentences

    Faker generates fake data for Ruby tests. Open compounds can now be switched off, so multi-word phrases no longer break the requested word count.

    Merged PR #2109

  • 2024 · wouterken/rulp

    HiGHS solver support for Rulp

    Rulp is a Ruby DSL for linear and mixed-integer programming. I added support for the open-source HiGHS solver and fixed several runtime issues.

    Merged PR #16

  • 2022 · isleofcode/corber

    xctrace instead of instruments in Corber

    Corber is a CLI for building hybrid mobile apps from Ember, Vue and Glimmer projects. I replaced the instruments tool with xctrace, so iOS builds work on macOS Monterey.

    Merged PR #698

More on GitHub

Education

  • – now

    PhD candidate, Information and Communication Technology

    Military University of Technology (WAT)

    Energy-efficient routing in FANETs, see Research.

  • –

    MScEng, Computer Science

    Warsaw University of Technology, Faculty of Electronics and Information Technology

    Routing algorithms and optimisation techniques that cut the energy use of data-centre network devices while keeping the infrastructure reliable.

  • –

    BScEng, Computer Science

    Warsaw University of Technology, Faculty of Electronics and Information Technology

    Built a lightweight cloud-computing platform for creating and managing VM instances, based on KVM, VXLAN networking and object storage.

Certifications

  • Oracle Cloud Infrastructure 2021 Certified Architect Professional

    Oracle’s advanced OCI architecture credential, built on top of the Associate level. It covers designing complex solutions, hybrid cloud, migrating on-premises workloads, and security and compliance.

    ID 274725590OCICAP2021OPN

  • (2021 edition) · (2019 edition)

    Oracle Cloud Infrastructure Certified Architect Associate

    Designing and deploying infrastructure on Oracle Cloud: identity and access management, virtual cloud networks, compute, storage and databases. Earned for two exam editions.

    IDs 274725590OCIAA2021CA · 274725590OCSIAAS2019

  • Oracle Cloud Infrastructure Foundations 2020 Certified Associate

    Entry-level OCI credential covering cloud concepts and economics, Oracle Cloud’s core services, and its security, pricing and support models.

    ID 274725590OCIBF2020-F

  • Valid until

    EU drone pilot, open category A1/A3

    EU remote-pilot competency for “open” category drone flights, passed with the Polish Air Navigation Services Agency (PANSA). The exam covers air safety, airspace restrictions, aviation regulations, operational procedures, privacy and security.

Mini-game