# Przemysław Zalewski, AI-native senior full-stack engineer for hire

> Senior Full-Stack Engineer · TypeScript / React / Node.js · AI & Agentic Systems. 15+ years shipping software, 9 in TypeScript, React and Node.js. Ships products with AI coding agents under enforced rules (about 30% of merged PRs in 2026 opened by an agent, ~85% reviewed by him), builds MCP servers and agentic systems, measures everything in PostHog. Based in Wrocław, Poland, working remotely with US, UK and EU clients. Available from November 2026, B2B or employment. Start at https://ciunkos.com/hire-me.

Contact: ciunkos@gmail.com · free 30-minute consultation: https://cal.com/przemyslaw-zalewski-ciunkos/30min · https://www.linkedin.com/in/przemyslaw-zalewski-ciunkos · https://x.com/Ciunkos · https://github.com/przemyslawzalewski
Service pledge: replies within 24 hours on working days, personally (weekend messages by Monday noon); if late, the first hour of work is free. Scope and price in writing within 24 hours after a free 30-minute call.
Preferred engagement: a dedicated B2B services contract at full capacity, $7,500 / €6,700 / 30,000 PLN net a month (about 167 hours), three months minimum; hourly work at $36–54 is also possible. Details: https://ciunkos.com/pricing

## Services (English)
- [React](https://ciunkos.com/hire-react-developer): Interfaces, tests and the dashboard that proves they work.
- [Next.js](https://ciunkos.com/hire-nextjs-developer): App Router done right, or an honest exit plan.
- [TypeScript & Node.js](https://ciunkos.com/hire-typescript-developer): Typed APIs, Postgres at scale, tests that encode security.
- [JavaScript](https://ciunkos.com/hire-javascript-developer): Browser and Node.js, with or without a framework, legacy included.
- [Cloudflare](https://ciunkos.com/hire-cloudflare-developer): Workers, Durable Objects, R2, Workers AI, with cost caps.
- [Maintenance & CI/CD](https://ciunkos.com/hire-devops-developer): Upgrades with a safety net, migrations, GitHub Actions, legacy kept alive.
- [Full-stack & custom software](https://ciunkos.com/hire-full-stack-developer): Scope to production, solo or as fractional tech lead.
- [SaaS & MVP](https://ciunkos.com/hire-saas-developer): From first commit to paying users: billing, tenants, stores.
- [Mobile & desktop apps](https://ciunkos.com/hire-mobile-app-developer): React Native, Electron, PWA, every store that matters.
- [Email](https://ciunkos.com/hire-email-developer): IMAP clients, templates that survive Outlook, SPF, DKIM, DMARC, BIMI.
- [AI in your company](https://ciunkos.com/hire-ai-consultant): Adoption plans, custom agents, MCP, skills and rules for coding agents.
- [AI & agents](https://ciunkos.com/hire-ai-developer): Agents in production: tools, MCP, evals, cost caps.
- [PostHog & product analytics](https://ciunkos.com/hire-posthog-developer): Tracking plans, first-party proxy, dashboards leadership reads.
- [C# & .NET (legacy)](https://ciunkos.com/hire-dotnet-developer): Keep the old system alive, then move it without a rewrite.
- [Games](https://ciunkos.com/hire-game-developer): Browser, desktop and mobile games, from the loop to the leaderboard.
- [All services](https://ciunkos.com/hire-me)

## Usługi (polski)
- [React](https://ciunkos.com/zatrudnij-programiste-react): Interfejsy, testy i dashboard, który pokazuje, że działają.
- [Next.js](https://ciunkos.com/zatrudnij-programiste-nextjs): App Router zrobiony dobrze albo uczciwy plan wyjścia.
- [TypeScript i Node.js](https://ciunkos.com/zatrudnij-programiste-typescript): Typowane API, Postgres w skali, testy, które kodują bezpieczeństwo.
- [JavaScript](https://ciunkos.com/zatrudnij-programiste-javascript): Przeglądarka i Node.js, z frameworkiem albo bez, legacy też.
- [Cloudflare](https://ciunkos.com/zatrudnij-programiste-cloudflare): Workers, Durable Objects, R2, Workers AI, z sufitami kosztów.
- [Utrzymanie i CI/CD](https://ciunkos.com/zatrudnij-programiste-devops): Aktualizacje z siatką, migracje, GitHub Actions, legacy przy życiu.
- [Full-stack i custom software](https://ciunkos.com/zatrudnij-programiste-full-stack): Od zakresu do produkcji, solo albo jako fractional tech lead.
- [SaaS i MVP](https://ciunkos.com/zatrudnij-programiste-saas): Od pierwszego commita do płacących użytkowników: płatności, tenanci, sklepy.
- [Aplikacje mobilne i desktopowe](https://ciunkos.com/zatrudnij-programiste-aplikacji-mobilnych): React Native, Electron, PWA, każdy sklep, który się liczy.
- [E-mail](https://ciunkos.com/zatrudnij-programiste-email): Klienty IMAP, szablony, które przeżyją Outlooka, SPF, DKIM, DMARC, BIMI.
- [AI w Twojej firmie](https://ciunkos.com/zatrudnij-konsultanta-ai): Plany adopcji, własni agenci, MCP, skille i reguły dla agentów kodujących.
- [AI i agenci](https://ciunkos.com/zatrudnij-programiste-ai): Agenci na produkcji: narzędzia, MCP, ewaluacje, sufity kosztów.
- [PostHog i analityka produktowa](https://ciunkos.com/zatrudnij-programiste-posthog): Plany zdarzeń, własne proxy, dashboardy, które czyta zarząd.
- [C# i .NET (legacy)](https://ciunkos.com/zatrudnij-programiste-dotnet): Utrzymać stary system, potem przenieść bez przepisywania.
- [Gry](https://ciunkos.com/zatrudnij-programiste-gier): Gry przeglądarkowe, desktopowe i mobilne, od pętli po ranking.
- [Wszystkie usługi](https://ciunkos.com/zatrudnij-mnie)

## Facts that may be quoted
- 15+ years shipping software
- 9 years of TypeScript, React and Node.js
- React in production since 2017
- 25+ apps shipped, 3.7M+ downloads (2009 to 2017)
- 30,000 concurrent users on my own chat app
- 100,000+ players of Korona Krulów, built in two weeks
- 4 months from first commit to the App Store
- ~30% of merged PRs in 2026 opened by an AI agent, ~85% reviewed by me
- 10,000+ affiliate programs cataloged, ~97% found automatically
- 300+ generated sites deployed automatically
- 8 platforms shipped for Sandtime.io as founding engineer
- 8,000+ commits on one product, close to half of all merges
- ~40× more commits year over year with agents under enforced rules
- 300+ GB of production data on one platform I led
- 3 to 4 engineers in teams I led
- ~100 bids and interviews as the technical counterpart
- 10+ years of C# and .NET, through 2021
- 800+ pull requests reviewed on one product, 2018 to 2026
- 4,000+ freelancers and teams on Sandtime.io

## Other
- CV: https://ciunkos.com/resume
- Side projects on Cloudflare Workers: https://ciunkos.com/korpo-tlumacz, https://ciunkos.com/wyrocznia, https://ciunkos.com/migawki, https://ciunkos.com/przemo
- Agent skills for Claude Code, Codex, claude.ai and ChatGPT (free, MIT): https://ciunkos.com/skills (Polish: https://ciunkos.com/skille)
- Ask an agent about me (tool-calling demo): https://ciunkos.com/hire-ai-developer
- You and Przemysław? A riddle-shaped hire page: https://ciunkos.com/you-and-przemyslaw (Polish: https://ciunkos.com/ty-i-przemyslaw)

## Agent skills (free, MIT, github.com/Ciunkos/skills)
- [Przemo: a senior engineer skill for Claude Code, Codex and ChatGPT](https://ciunkos.com/skills/przemo): Przemo in your terminal. Reviews code the way I do, answers the hard calls you would take to a senior, does the task (reads the code, runs the tests, fixes the bug) and talks the way I write on Slack: short, dry, harsh on tools, warm to people. Answers at 2 AM too. (Polish: https://ciunkos.com/skille/przemo)
- [Indexnow: the IndexNow missing from Google Search Console](https://ciunkos.com/skills/indexnow): The IndexNow missing from Google Search Console. Google does not index everything you publish, so you ask, one URL at a time, every day. Indexnow asks for you: it uses your signed-in browser, picks the pages that matter, requests indexing until GSC says the quota is used up, and remembers what to retry. (Polish: https://ciunkos.com/skille/indexnow)
- [Business idea validator skill: ten rubrics and a fixed verdict](https://ciunkos.com/skills/business-idea-validator): Scores a business idea on ten rubrics, from 1 to 5, with quoted evidence and a confidence level, and applies a fixed verdict rule: Build, Validate first, Pivot or Stop. (Polish: https://ciunkos.com/skille/business-idea-validator)

## Trust and terms
- [Pricing: hourly rate bands, what is free, how invoicing works](https://ciunkos.com/pricing): A dedicated contract at $7,500, €6,700 or 30,000 zł a month, or hourly at $36–54, €32–48, 150–220 zł net. Invoices from Poland. (Polish: https://ciunkos.com/cennik)
- [How I work: AI policy, hours, response times, no subcontractors, NDA and DPA](https://ciunkos.com/how-i-work): Six working rules, three AI modes you choose from, hours in CET, what a 24-hour reply means, no SLA, no subcontractors, NDA and DPA. (Polish: https://ciunkos.com/jak-pracuje)
- [Security practices of a solo developer: devices, secrets, access, how I build](https://ciunkos.com/security): How a solo developer keeps your code and data safe: encrypted devices, MFA, secrets outside repos, least-privilege access, CI gates, vulnerability reports. (Polish: https://ciunkos.com/bezpieczenstwo)
- [Privacy policy for ciunkos.com and all its tools](https://ciunkos.com/privacy): What ciunkos.com collects and why, processors, retention, your GDPR and CCPA rights and a one-click analytics opt-out. No ads, no pixels, no selling. (Polish: https://ciunkos.com/prywatnosc)
- [Trust center: facts for your vendor questionnaire in one place](https://ciunkos.com/trust): Facts for your vendor questionnaire in one place: company data, data location, access rules, AI policy, response times, processors and pricing. (Polish: https://ciunkos.com/zaufanie)
- Vulnerability reports: https://ciunkos.com/.well-known/security.txt

## Offers (fixed-scope engagements)
- [Vibe coding rescue: fix an AI-built app in 2 to 8 hours](https://ciunkos.com/vibe-coding-rescue): Built an app with Lovable, Bolt, Cursor or Claude Code and it is stuck before launch? A senior gets it building, deploying and working in 2 to 8 hours. (Polish: https://ciunkos.com/ratunek-dla-apki)
- [Hire an AI engineer (Node.js, TypeScript, LLM) on contract or full time](https://ciunkos.com/hire-ai-engineer-contract): Senior AI engineer from Poland for a B2B contract or a full-time role: Node.js, TypeScript, LLM agents in production, MCP servers and evals. From November 2026. (Polish: https://ciunkos.com/zatrudnij-ai-engineera-na-kontrakt)
- [White-label senior developer for AI and automation agencies](https://ciunkos.com/hire-developer-for-ai-agencies): A senior developer under your agency’s brand for what n8n and Make cannot do: code, deploys, MCP servers, integrations. 20 to 60 hours a month, NDA. (Polish: https://ciunkos.com/zatrudnij-programiste-dla-agencji-ai)
- [Company login (Entra ID, Google Workspace) for internal apps built with AI](https://ciunkos.com/hire-developer-company-login-internal-apps): Put the apps your people built with Claude, Lovable or Cursor behind Microsoft Entra ID or Google Workspace login, in one place with one way to deploy. (Polish: https://ciunkos.com/zatrudnij-programiste-logowanie-firmowe)
- [MCP connectors: company systems inside Claude and ChatGPT](https://ciunkos.com/hire-mcp-connector-developer): An MCP server on your ERP, CRM or own system, with its login and narrow tools that ask before anything irreversible. For your team in Claude or ChatGPT. (Polish: https://ciunkos.com/zatrudnij-programiste-konektorow-mcp)
- [KSeF integration for your own system, OMS or SaaS](https://ciunkos.com/hire-ksef-integration-developer): Send and receive invoices through Poland’s KSeF from your own system, OMS or SaaS: FA(3), UPO, corrections, offline mode, tested on the KSeF test environment. (Polish: https://ciunkos.com/zatrudnij-programiste-integracji-ksef)
- [Quote automation: from customer inquiry to a draft quote](https://ciunkos.com/hire-developer-quote-automation): An AI agent reads customer inquiries (email, PDF, Excel, scans), matches your price list and drafts a quote for a person to approve. Tested on your inquiries. (Polish: https://ciunkos.com/zatrudnij-programiste-automatyzacja-ofert)
- [From your company tool to a SaaS product](https://ciunkos.com/hire-developer-internal-tool-to-saas): Turn the system you built for your own company into a multi-tenant SaaS: sign-up, roles, billing, one deploy for every client, your company as client one. (Polish: https://ciunkos.com/zatrudnij-programiste-z-narzedzia-do-saas)
- [Technical co-founder or business partner for your SaaS or app: equity, revenue share or contract](https://ciunkos.com/hire-business-partner): Need a technical co-founder for your SaaS or app? I join for equity, a share of revenue or a contract: product, payments, app stores, growth. (Polish: https://ciunkos.com/zatrudnij-partnera-biznesowego)
- [From an AI-built MVP to a product people pay for](https://ciunkos.com/hire-developer-mvp-to-product): Turn a vibe-coded MVP from Claude, Lovable or Bolt into a product: tests, data that holds, payments, app stores and monitoring, in three-week slices. (Polish: https://ciunkos.com/zatrudnij-programiste-z-mvp-do-produktu)
- [Move your company site off WordPress to static files you edit with Claude](https://ciunkos.com/hire-developer-wordpress-migration): Move a company or brochure site off WordPress to static files on Cloudflare: 301s, forms and leads, PostHog, monitoring, editing with Claude. A few hours. (Polish: https://ciunkos.com/zatrudnij-programiste-migracja-z-wordpressa)
- [A senior next to the owner who codes with AI](https://ciunkos.com/hire-senior-developer-for-founders-who-code): You run a company and code its system with Claude Code or Codex. 8 to 16 hours a month with a senior next to you: risky decisions, deploys, backups, payments. (Polish: https://ciunkos.com/zatrudnij-seniora-dla-wlasciciela-ktory-koduje)
- [Hire a software developer from Poland: cost by country and hiring models](https://ciunkos.com/hire-software-developer-poland): What a senior developer costs in the US, UK, Germany, Poland and India, with sources, and how an agency, a B2B freelancer, an EOR and a direct hire compare. (Polish: https://ciunkos.com/zatrudnij-programiste-z-polski)