# Mariusz P.

> Senior Frontend Engineer

Location: Gdańsk, Pomorskie, Poland
Profile: https://flows.cv/mariusz

## Work Experience
### Senior Frontend Engineer @ Elfsquad
Jan 2025 – Present | Drachten, Friesland, Holandia

### Senior Frontend Engineer @ ITSurance Group Sp. z o. o.
Jan 2023 – Jan 2025 | Warsaw, Mazowieckie, Poland
▷ Designed and implemented user flows that feel easy and approachable, even in complex enterprise apps (React, Redux, TypeScript).
▷ Shaped, implemented, and nurtured several design systems from the ground up (Figma, Styled Components).
▷ Built, rebuilt, and improved components and FE logic, mentored junior devs, conducted reviews and architectural brainstorming.
▷ Refactored and improved codebases to make the code cleaner and developer experience smoother (Node.js, Vite).

### Senior User Interface Engineer @ Banked :
Jan 2022 – Jan 2023 | London, England, United Kingdom
▷ Crafted beautiful, responsive UI elements, keeping them accessible, polished, and easy to use (Web Components, Lit, TypeScript).
▷ Made fellow developers' lives easier by tweaking local environments and setup scripts, coaching junior colleagues, speeding up tests and improving observability (Jest, Cypress, GitHub, Node, Bash).
▷ Worked closely with designers, kept our design system in sync, enforced proper accessibility (a11y) and i18n standards (Storybook, i18n).

### Principal Frontend Engineer @ Furgonetka
Jan 2021 – Jan 2022 | Elbląg, Warmińsko-mazurskie, Poland
▷ Took the lead building a customer-facing web app for return shipping of their e-commerce purchases - planning roadmaps, assigning team members to tasks they'd perform best at, and making sure milestones are delivered on time (React, TypeScript, MobX, Sentry).
▷ Managed and mentored a remote crew of five rising frontend devs by leading the hiring of new teammates, planning their career growth, and sharing what I know about TypeScript and React. Also, resolving occasional personal conflicts.
▷ Guided app architecture, mapped out development sprints, handled releases, and wrestled with integrations (CI/CD, GitHub, Node.js).
▷ Kept things running: collaborated both internally with backend/API teams and with outsourced partners, oversaw hiring (and interviewed candidates), looked after our design system with the design team.

### Senior Frontend Engineer (UI) @ Typeform.com
Jan 2020 – Jan 2021 | Barcelona, Catalonia, Spain
▷ Introduced new UI components and features for forms, which was especially tricky, as related pieces were scattered among numerous frontend and backend codebases and multiple code owners (React, TypeScript, Cypress, Node).
▷  Collaborated closely with design folks to make sure everything looked and felt right (Figma, Storybook).
▷ Implemented basic A/B testing tools and added support for feature flags and progressive rollouts.

### Staff Frontend Engineer @ Livespace - Sell Smarter
Jan 2018 – Jan 2020 | Warszawa, Woj. Mazowieckie, Polska
▷ Managed a close-knit, fully remote team and tackled challenges of migrating a legacy, seven-year-old app from jQuery to React.
▷ Planned, refactored, and implemented a lot of frontend architectural elements and user interface components, while maintaining legacy code and fixing exotic bugs reported by users (jQuery, React, Redux, TypeScript, Sass).
▷ Was responsible for communication with stakeholders, hiring, technical interviews, performance reviews, and making sure that despite everyone working remotely, everyone's morale is high and they feel at home.

### Frontend Engineer @ Livespace - Sell Smarter
Jan 2015 – Jan 2018 | Remote
▷ Built and maintained a customer-facing SaaS app (JavaScript, jQuery, Smarty, HTML, CSS)
▷ Advanced jQuery, i.e. custom widgets/components, custom events, non-trivial event management
▷ Presented and explained new features during live sprint demos

### Coding Mentor @ Kodilla
Jan 2016 – Jan 2019 | Remote
▷ Mentored over 50 learners, many of whom became skilled programmers, and all of whom claimed to have enjoyed the journey.
▷ One-on-one remote mentoring where I got to share my coding knowledge via code reviews and weekly meetings, and watch complete newbies get their first "aha!" moments (React, Redux, JavaScript, Node.js, Sass, CSS, HTML).
▷ Did live code reviews, pair programming, and gave lectures about best coding practices, and how frontend works, in detail.

### Frontend Developer @ Little Llama Studio
Jan 2011 – Jan 2014
▷ Developed small, interactive (looking back - also kind of silly) websites for various clients (JavaScript, WordPress, PHP, Adobe Flash, ActionScript).
▷ Built several simple educational games, which, believe it or not, were actually burned onto CDs! (ActionScript, Adobe Flash, JavaScript).
▷ Made a couple of "interactive experiences" in Flash, e.g., highly animated and interactive business presentations (back when PowerPoint was bad).
▷ Created and provided support for browser-based strategy games (JavaScript, PHP).


## Education
### Informatyka
Polish-Japanese Academy of Information Technology


## Contact & Social
- LinkedIn: https://linkedin.com/in/mariusz-peplinski
- Portfolio: https://www.linkedin.com/redir/phishing-page?url=marez%2exyz

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Source: https://flows.cv/mariusz
JSON Resume: https://flows.cv/mariusz/resume.json
Last updated: 2026-03-31