Job offersFreelancers🔥 PLUSMembership

🔥 PLUSAvailable

Michal Zak

Software Test Engineer

Hourly: 24.527

Level: Senior

Registered: 03.02.2025

Availability: As needed, Full-time / contract

VývojQA / Tester
JavaScriptReactSoftware TestingTypescript

I thrive in fast-paced startup environments and recognize the critical importance of early bug detection. Because of this, I prioritize 'shift-left' testing methodologies to catch and address potential issues as early in the development lifecycle as possible.

My technical background spans modern testing frameworks—including Playwright, Cypress, Jest, Vitest, and K6—alongside JavaScript ecosystems (Node.js, React), PostgreSQL, and AWS. Additionally, I integrate AI agents and CLI tools (such as Claude Code or Antigravity CLI) directly into my testing workflows to accelerate test script generation, expand edge-case coverage, and streamline test maintenance to keep execution fast and flake-free.

Using this stack and CI/CD platforms like GitHub Actions, GitLab CI, and Bitbucket, I build scalable test suites across E2E, API, component, unit, and performance layers.

Finally, I thrive in remote setups where I can leverage flexibility and deep focus to deliver high-quality work.

Portfolio

Trezor, Prague August 2025 - June 2026

Projects:

Trezor Suite (Open-source app for secure hardware wallet management)

  • Developed Playwright E2E test suites for core crypto workflows (onboarding, passphrase, analytics, etc.)
  • Resolved CI test flakiness and Electron teardown timeouts in GitHub Actions test pipelines
  • Built automated test verification for product analytics events and link integrity

TechStack: TS, Node.js, React, Playwright, Python, GitHub Actions

Instea, Bratislava August 2023 - June 2025

Projects:

US Quick Online 1.0 & 2.0 (B2B web-based app to manage clinical supply chain logistics)

  • Developed & maintained performance tests using K6 with JavaScript for both projects

US Quick Dispatch Dashboard (Internal web-based app for dispatching international shipments)

  • Developed & maintained E2E/API tests using Playwright with JavaScript
  • Configured and maintained CI pipeline in Jenkins to streamline application testing

TechStack: JS, Node.js, React, GraphQL, Git (GitHub/Bitbucket), MS Playwright, Grafana Labs K6, Docker, Jenkins

Vectary, Bratislava

(Online 3D design and augmented reality platform)

  • Developed and maintained E2E/API tests using Cypress.io
  • Configured and maintained CI pipeline in Bitbucket to streamline application testing

TechStack: JS/TS, GraphQL, Git (Bitbucket), Docker, Cypress.io

Vestberry, Bratislava

(B2B SaaS for VC portfolio management, providing data insights and automated reporting)

  • Implemented an automated testing framework with Cypress.io that followed best practices
  • Developed and maintained E2E/API tests using Cypress.io
  • Configured and maintained CI pipeline in GitLab to streamline application testing

TechStack: JS/TS, Node.js, React, Postgres, GraphQL, Git (GitLab), Docker, Cypress.io, Jest

Awards, certifications

ISTQB Certified Tester Foundation Level, License 297

Michal Zak 🔥 PLUS freelancer!

Switch to PLUS and get more! Enjoy benefits that put you in the spotlight.
Learn more

Hourly: 24.527

Level: Senior

Registered: 03.02.2025

Availability: As needed, Full-time / contract