Alex Kiersnowski

Senior Product Designer & Design Engineer · Warsaw, Poland (CET) · Remote, EU & US Eastern hours

alex.kiersnowski@gmail.com · linkedin.com/in/alexkiersnowski · kiersnowski.com

Stack

Frontend: React · Next.js · TypeScript · Tailwind CSS · shadcn/ui · Radix
Mobile: React Native · Expo
Backend: Supabase (Postgres, RLS) · Auth · Stripe · Vercel
Design & AI: Figma · Claude Code · Cursor · Anthropic API · OpenAI API

Summary

Senior Product Designer & Design Engineer with 10+ years bridging product design and production code. I ship full-stack web and mobile products end to end, using AI-native workflows and LLM integrations to move from idea to production in days, not weeks. Simply put: I take a product problem, decide what's worth building, ship it to real users, and find out whether they'll use it and pay for it. I do my best work in early-stage startups and fast-moving, high-autonomy teams.

Experience

Senior Product Designer / Design Engineer — Nord Security

Jul 2026 – Present · Contract · Warsaw, Poland · Hybrid

Worked within the NordVPN apps team alongside the design engineering team, building AI-assisted prototyping infrastructure for a 60+ person design team and its product owners.

  • Coded production-accurate front-end baselines of the NordVPN iOS and macOS apps (Connect, Real-Time Protection, Dark Web Monitor, Settings), handling complex interaction states and feature-dependent logic
  • Cut AI token consumption and saved hundreds of hours of prototyping time by providing designers a pre-built code baseline instead of generating repetitive UI from scratch
  • Shipped production code via GitLab merge requests to two core repositories: the internal AI prototyping platform and the Aurora AppKit design system

Venture & Product Builds

Design Engineer — Braza

Mar 2026 – May 2026 · Warsaw, Poland · Independent project

Full-stack bilingual operations platform designed and built solo for a planned performance nutrition startup. Paused before launch given the scale of the physical operations.

  • Engineered a macro engine (Mifflin-St Jeor BMR, PAL multipliers, protein yield) across 8 biometric inputs, producing personalised meal plans and weekly pricing per client, impossible to deliver manually
  • Built a production sheet system that generates per-meal kitchen briefs with yield-adjusted shopping lists, removing manual calculation from the weekly order cycle
  • Integrated the Anthropic Claude API as a bilingual (EN/PL) natural language command bar, designed to cut order entry to under a minute per customer and handle 100+ weekly orders in under an hour

Stack: Next.js · TypeScript · Supabase · Tailwind · shadcn/ui · Anthropic Claude API · next-intl · Vercel

Founder & Design Engineer — Fiive

Mar 2024 – Feb 2026 · Remote

B2B SaaS agency-client operations platform centralising requests, tasks, projects, and collaboration in a shared workspace.

  • Led end-to-end product research under JTBD framework, conducting 19 interviews with senior agency and client stakeholders and synthesising findings into feature prioritisation
  • Architected a secure multi-tenant backend with RLS policies and a broad relational domain model ensuring zero data leakage across organisation boundaries
  • Integrated production billing via Stripe with webhook processing, signature verification, and full payment lifecycle management
  • Designed for scale from MVP with virtualised rendering and query performance optimisation verified to 10,000+ tasks per organisation
  • Compressed an estimated 12 months of development into 12 weeks using AI-assisted workflows, eliminating an estimated €250-500K in initial funding requirement
  • Launched to 20+ organisations across the UK and EU, with active users in both agency and client roles

Stack: Next.js · React · TypeScript · Supabase · Tailwind · shadcn/ui · TanStack · Stripe · Resend · Vercel

Lead Product Designer — BPP

Jul 2023 – Mar 2024 · Contract · London, UK · Hybrid

One of the UK's largest professional education providers, undergoing a large-scale digital transformation.

  • Led an organisation-wide design system build from scratch, establishing Figma variables, token structures, WCAG AA specs (incl. ARIA) and component props
  • Embedded with engineering teams to publish Zeroheight documentation, contribute to Storybook and ensure UI parity across Product and Tech

Senior Product Designer — eBay / Adevinta

Sep 2021 – Sep 2022 · Contract · Berlin, Germany · Hybrid

MOVE, eBay's automotive classifieds unit (mobile.de, Kijiji Autos), later acquired by Adevinta.

  • Built one design system shared across B2C, C2C and C2B marketplaces, integrated into the development pipeline via Storybook and Jenkins
  • Led UX for trade-in functionality on mobile.de and localised the system post-acquisition for Canadian and Australian markets

Senior Experience Designer — Konrad Group

Mar 2020 – Sep 2021 · Full-time · Toronto, Canada · Hybrid

Full-service digital consultancy delivering strategy and design for global brands.

  • Led UX for WestJet's in-flight entertainment system across 150+ aircraft, serving 22M guests a year
  • Redesigned Deloitte KX and restructured the information architecture for Marks & Spencer's mobile app

Further 5+ years prior experience in junior and mid-level roles across London agencies.

Languages

English (Native) · Polish (A2) · Spanish (B1)

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