Dawid Rusnak

Software Engineer and Architect

I'm a Software Architect and Full-Stack Developer with a passion for building high-performance, scalable, robust, and maintainable systems and refining the developer experience. I've worked across product companies, software houses, and startups, tackling a wide range of challenges and finding ways to make software not just work, but work efficiently. Many times I had a chance to lead initiatives of iterative software migration.

Beyond coding, I contribute by driving technical decisions, improving workflows, and making development more efficient. I enjoy sharing knowledge through mentoring, workshops, and architectural guidance, helping teams work smarter and build better software.

My expertise is quite broad, but I most enjoy challenges on performance, security, and automation, especially in the area of developer tooling.

I have worked with a wide range of technologies across different types of projects, from product companies to software houses. My experience spans both backend and frontend development, as well as DevOps and automation. While the list here isn’t exhaustive, it reflects the key technologies I've used extensively. I'm always curious about new tools and approaches - especially when they bring real value.

My recent focus has been on Golang and TypeScript, but I also worked with Python and many other languages in my career. I prefer PostgreSQL as a first choice, but I've also worked other databases, i.e. MongoDB, Redis, ElasticSearch, or DynamoDB. I have strong expertise in SOA, microservices, and distributed systems, I worked with serverless too. AWS is my preferred cloud platform, but I've also worked with GCP and Azure. I'm highly experienced with optimizing performance, security, and developer tooling.

I've worked on a variety of frontend projects and prefer the React ecosystem, but I also have 2 years of Vue.js experience and other frameworks too. Over the years, I've worked with various frontend stacks, including Angular, Angular.js, Backbone, and more. I prefer SCSS but have worked with CSS-in-JS, Less, and others. I have strong experience building performant, maintainable, and scalable frontend applications.

I have deep expertise in Docker and Kubernetes, with experience in optimizing containerized workloads. I'm well-versed in CI/CD pipelines, including Jenkins, GitLab, and GitHub Actions, and have hands-on experience with Terraform, Helm Charts, and infrastructure automation.

I have a strong passion for performance optimization, ensuring efficiency across the entire software stack. I'm highly skilled in automation, improving developer workflows and system reliability. I've worked with many message queues, including RabbitMQ, Kafka, and cloud-native solutions.

Over the years, I've taken on a variety of roles, from hands-on development to architecture design and leading full software development lifecycles (SDLC) for both startups and established companies.

I've highlighted here the full-time positions I've been working on. Besides that, I also worked on independent projects and consulting. I'm passionate about designing scalable, high-quality systems and enjoy working with teams that value clean architecture and well-thought-out engineering decisions. If you're curious about specific projects, feel free to reach out, or check out my LinkedIn for a broader view.

Full-stack Developer and Technical LeadTestkube

March 2023now 2 years

I led a frontend re-architecture for modularity and code reuse, then designed and implemented a backend for new test orchestration system (Test Workflows), enabling scalable, flexible, and distributed Kubernetes-based execution. I prepared a full system re-architecture to enhance security, performance, and multi-cluster support. As a technical leader, I drove architectural decisions, optimized scalability, and mentored the team while working with Golang, React, NATS, and MongoDB.

Frontend Developer and Technical LeadEvident ID

September 2019April 2022 2 years 8 months

I led the Frontend team and drove system modernization by migrating from Mithril.js to Vue.js, improving performance, configurability, and accelerating feature delivery. Architected and built FE solutions for risk management tools, enhanced CI/CD pipelines, and optimized developer workflows. Shaped system architecture, contributing to scalable backend solutions in Python and Scala.

Senior Frontend Developer and Technical LeadTalixo

March 2018February 2019 1 year

I led front-end rearchitecture of a transportation platform, migrating from jQuery to React + Redux. Built a WYSIWYG editor reducing landing page setup from days to minutes. Optimized Python/Django backend, improved scalability, mentored engineers, and enhanced software delivery processes. Contributed to open-source UI Kit and SCSS tooling.

Senior Software Developer and Technical LeadG2A

January 2017October 2017 10 months

Together with my previous team and CTO from Grand Parade, after its acquisition, we have joined G2A - a major digital marketplace to enhance architecture, modernize software, and mentor teams. Led integration system development, front-end migration to React, and a microservices lottery platform. Improved software lifecycle, scalability, and developer experience while ensuring resilient, high-performance solutions under tight deadlines.

Senior Frontend Developer and Technical LeadGrand Parade

June 2015September 2016 1 year 4 months

As a technical leader in a software house specializing in bookmaker and casino platforms, I led React adoption, modernized frontend technologies, and designed scalable architectures. I mentored developers, conducted recruitment, and led frontend and Node.js backend development for a high-performance betting platform. I also guided teams through architectural challenges and deadline-driven projects.

Senior Frontend Developer and Technical LeadTribeCoders

May 2014April 2015 1 year

Developed and optimized front-end applications with AngularJS, Backbone.js, and PhoneGap while contributing to back-end work in Scala, CakePHP, and Ruby on Rails. Improved UX, search, and architecture for diverse projects, including high-traffic platforms. Provided technical leadership, mentoring, and support under critical deadlines.

Web Application DeveloperCodete

September 2013May 2014 9 months

Developed and maintained web applications as a full-stack developer using PHP (Yii, Zend), Java (Play), and JavaScript (AngularJS, Node.js, PhoneGap). Led a project management tool, improved an e-commerce platform, and built a WYSIWYG landing page editor, optimizing performance and usability.

I've been working on many open source projects, some of them has reached public phase. I selected some of them, which - in my opinion - shows better my skills. You may also want to see my GitHub.

Testkubeorchestrating tests in Kubernetes

March 2023

System for orchestrating tests and other workflows in the Kubernetes clusters.

Repository Documentation

Socketyfast protocol over TCP

December 2022

Lightweight protocol over TCP with performance in mind, with Golang and Node.js implementation.

Spec Node.js Golang

sass-merge

September 2018

Tool for merging multiple Sass (Sass and SCSS syntax) and CSS files into a single, optimized stylesheet in selected output format.

Repository NPM Registry

Talixo UI KitReact UI framework

May 2018

Complete UI framework based on React and Sass, which allows pretty good customization. Has 50+ mobile-friendly functional components for wide use.

Repository Storybook

object-regexpRegular Expressions for objects

January 2018

Node.js library, which aims for building matching expression mechanism, using objects instead of text.

Repository NPM Registry

universal-lexerultra-fast dynamic lexer

January 2018

Node.js library, which may create ultra fast lexer (output only JavaScript code), based on lexical definition. It makes some additional optimizations to basic regular expressions.

Repository NPM Registry

easen-modelsfunctional models with validation

June 2017

Define models and use them for mapping or/and as validators. Successfully used in multiple production‑ready services.

Repository NPM Registry

easen-didependency injection in JavaScript

August 2016

Provides simple DI container which uses Proxy for safety, lazy loading and additional tooling.

Repository NPM Registry

Beside internal workshops and lectures I've done, I had some occasions to talk on public events.

Metaprogramming in JSCareerCon

September 2017

I made a presentation about metaprogramming in JavaScript, mostly focused on reflective programming. It was prepared with junior/regular developers in mind.

Slides

Node.js behind: V8 engine and its optimizationsCode Europe

April 2017

I prepared a presentation about JavaScript performance on front‑end and back‑end, mostly basing on the V8 engine. I lead it for 200+ persons on Code Europe 2017 in Kraków, and later for ~100 persons on Meet.js as well.

Slides Recording

Real‑time web apps with React/ReduxSFI

March 2016

I have prepared 3‑hour workshops, on which people had an opportunity to learn about React and Redux, and how to work with real‑time data on front‑end (incl. socket.io).

Slides Repository

If you are interested in setting up project or longer cooperation with me, don't hesitate to contact me in any way.

VAT Number PL9442246323

NIP 9442246323

REGON 123128644

Dawid Rusnak

Software Engineer and Architect

About Me

Technologies

Selected Experience

Selected Open Source

Talks

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