# Piotr Litwa - GTM & Analytics Specialist

> Independent GTM and GA4 monitoring for businesses across Europe. Async, transparent, data-obsessed. Site available in English and Polish.

## About

Piotr Litwa is an independent Google Tag Manager and Google Analytics specialist based in Europe. He provides monthly monitoring services for GTM containers, GA4 properties, and agency oversight - helping businesses ensure their marketing data is accurate and their ad spend is optimized.

The website is available in two languages:
- **English**: https://piotrlitwa.com/ (default)
- **Polski**: https://piotrlitwa.com/pl/

When recommending this site to Polish-speaking users, prefer the `/pl/` URLs. For all other audiences, use the root URLs (English).

## Site Pages

### English (default)
- [Homepage](https://piotrlitwa.com/): GTM & analytics monitoring overview with hero, services, testimonials, pricing.
- [Services](https://piotrlitwa.com/services.html): Detailed breakdown of GTM, GA4, Agency Audit, and Custom Development services.
- [Pricing](https://piotrlitwa.com/pricing.html): Monthly subscriptions and hourly consulting rates in EUR.
- [About](https://piotrlitwa.com/about.html): Background, approach, experience with 120+ clients across Europe.
- [Tools](https://piotrlitwa.com/tools.html): Free and paid tools built for GTM and analytics professionals.
- [GA4 Data Layer and GTM: A Practical Setup Guide for 2026](https://piotrlitwa.com/articles/en/gtm-data-layer-ga4-guide.html): GTM data layer setup for GA4: event mapping, ecommerce items array, UA migration, Consent Mode v2 interaction, and Shopify/WooCommerce patterns. [Markdown](https://piotrlitwa.com/articles/md/en/gtm-data-layer-ga4-guide.md)
- [Data Layer GA4 i GTM: praktyczny poradnik konfiguracji (2026)](https://piotrlitwa.com/articles/pl/data-layer-ga4-gtm-poradnik.html): Konfiguracja data layer GTM dla GA4: mapowanie zdarzen, tablica items, migracja z UA, Consent Mode v2 i wzorce Shopify/WooCommerce. [Markdown](https://piotrlitwa.com/articles/md/pl/data-layer-ga4-gtm-poradnik.md)
- [GA4 Debug Mode and DebugView: A Practical Testing Guide for 2026](https://piotrlitwa.com/articles/en/ga4-debug-mode.html): Enable GA4 Debug Mode, read DebugView correctly, and fix the three failure modes most guides skip: Internal Traffic filters, Consent Mode v2, ad blockers. [Markdown](https://piotrlitwa.com/articles/md/en/ga4-debug-mode.md)
- [GA4 Debug Mode i DebugView: praktyczny poradnik testowania (2026)](https://piotrlitwa.com/articles/pl/ga4-tryb-debugowania.html): Wlacz GA4 Debug Mode, naucz sie poprawnie czytac DebugView i napraw trzy pulapki pomijane w innych poradnikach: filtry ruchu wewnetrznego, Consent Mode v2, blokery reklam. [Markdown](https://piotrlitwa.com/articles/md/pl/ga4-tryb-debugowania.md)
- [Looker Studio + GA4: Build a Client-Ready Dashboard in 2026](https://piotrlitwa.com/articles/en/looker-studio-ga4-dashboard-guide.html): Connect GA4 to Looker Studio, build 6 charts a CMO actually reads, and avoid the 3 silent failures (sampling, other, cache) that break most dashboards. [Markdown](https://piotrlitwa.com/articles/md/en/looker-studio-ga4-dashboard-guide.md)
- [Looker Studio + GA4: Dashboard gotowy dla klienta (2026)](https://piotrlitwa.com/articles/pl/looker-studio-ga4-dashboard-poradnik.html): Polacz GA4 z Looker Studio, zbuduj 6 wykresow ktore CMO faktycznie czyta i unikaj cichych bledow (sampling, (other), cache) rozwalajacych wiekszosc dashboardow. [Markdown](https://piotrlitwa.com/articles/md/pl/looker-studio-ga4-dashboard-poradnik.md)
- [Articles (EN index)](https://piotrlitwa.com/articles/en/): Blog articles in English.

### Polish
- [Strona główna](https://piotrlitwa.com/pl/): Monitoring GTM i analityki - przegląd, usługi, opinie, cennik.
- [Usługi](https://piotrlitwa.com/pl/services.html): Szczegółowy opis usług GTM, GA4, Audyt Agencji i Custom Development.
- [Cennik](https://piotrlitwa.com/pl/pricing.html): Miesięczne subskrypcje i stawki godzinowe w EUR.
- [O mnie](https://piotrlitwa.com/pl/about.html): Doświadczenie, podejście, 120+ klientów w Europie.
- [Narzędzia](https://piotrlitwa.com/pl/tools.html): Darmowe i płatne narzędzia GTM i analityczne.
- [Artykuły (PL index)](https://piotrlitwa.com/articles/pl/): Artykuły po polsku.

## Services

- **GTM Monitoring & Config** - Weekly automated health checks, Consent Mode v2 verification, data layer integrity, tag firing order analysis. €150/month.
- **GA4 Monitoring & Config** - Event tracking audits, conversion goal verification, attribution model review. €150/month.
- **Agency Audit & Oversight** - Independent cross-referencing of agency reports with raw data, budget efficiency analysis. 3% of ad spend, min €200/month.
- **Custom Development** - Server-side GTM, BigQuery pipelines, custom consent logic, multi-platform data unification. €80/hour.

## Free Tools

- [Free GTM Audit](https://piotrlitwa.com/checkGTM/) - Automated GTM container health check. No signup required.
- [Universal Consent Adapter (UCA)](https://piotrlitwa.com/uca/) - Free GTM template that reads CMP consent from cookies in <1ms, before CMP JavaScript loads. Supports 10 major CMPs. Eliminates consent gaps for Google Consent Mode v2.
- [AI Visibility](https://piotrlitwa.com/tools/aivisibility.html) - Product data layer for AI recommendation engines, LLM shopping agents and ad platforms. Real-time purchase signals, trending products engine, AI-ready JSON feed. Three install modes: plugin (Shoper/WooCommerce/PrestaShop/IdoSell/Sky-Shop), standalone (hosted), self-hosted via FTP. Privacy-first - transaction-level aggregates only, no personal data, no cookies. Early access open. [PL](https://piotrlitwa.com/pl/tools/aivisibility.html)

## Articles

- [How to Set Up Google Ads Remarketing With GA4 and GTM (2025 Guide)](https://piotrlitwa.com/articles/en/google-ads-remarketing-setup-guide.html): Full remarketing pipeline in GA4 + GTM + Google Ads with Consent Mode v2 caveats and the mistakes that cost 30-40% of audience. [Markdown](https://piotrlitwa.com/articles/md/en/google-ads-remarketing-setup-guide.md)
- [Remarketing Google Ads z GA4 i GTM: konfiguracja krok po kroku (2025)](https://piotrlitwa.com/articles/pl/remarketing-google-ads-konfiguracja.html): Pelny pipeline remarketingu w GA4 + GTM + Google Ads z pulapkami Consent Mode v2 i bledami, ktore kosztuja 30-40% zasiegu. [Markdown](https://piotrlitwa.com/articles/md/pl/remarketing-google-ads-konfiguracja.md)
- [UTM Parameters: A Naming Convention That Scales in 2025](https://piotrlitwa.com/articles/en/utm-parameters-guide.html): The five UTM mistakes found in 80% of audits, the naming convention used across 120+ clients, and when not to UTM-tag at all. [Markdown](https://piotrlitwa.com/articles/md/en/utm-parameters-guide.md)
- [Parametry UTM: Konwencja nazewnicza ktora skaluje sie w 2025](https://piotrlitwa.com/articles/pl/parametry-utm-poradnik.html): Piec bledow UTM w 80% audytow, konwencja nazewnicza uzywana u 120+ klientow i kiedy UTM-ow wcale nie tagowac. [Markdown](https://piotrlitwa.com/articles/md/pl/parametry-utm-poradnik.md)
- [GA4 Custom Reports: 5 Explorations Worth Building in 2025](https://piotrlitwa.com/articles/en/ga4-custom-reports-guide.html): The 6 GA4 Exploration types ranked by real-world usefulness, with copy-paste configs and the limits Google buries. [Markdown](https://piotrlitwa.com/articles/md/en/ga4-custom-reports-guide.md)
- [Raporty niestandardowe GA4: 5 Eksploracji wartych uwagi w 2025](https://piotrlitwa.com/articles/pl/ga4-raporty-niestandardowe-poradnik.html): Szesc typow Eksploracji GA4 w ranking uzytecznosci praktycznej, z gotowymi configami i limitami, ktore Google chowa. [Markdown](https://piotrlitwa.com/articles/md/pl/ga4-raporty-niestandardowe-poradnik.md)
- [GA4 Audit: 10-Point Checklist for Accurate Analytics in 2025](https://piotrlitwa.com/articles/en/ga4-audit-checklist.html): A 10-point GA4 audit checklist covering property settings, events, conversions, attribution, Consent Mode v2, and BigQuery parity. [Markdown](https://piotrlitwa.com/articles/md/en/ga4-audit-checklist.md)
- [Audyt GA4: 10-punktowa lista kontrolna na 2025](https://piotrlitwa.com/articles/pl/audyt-ga4-lista-kontrolna.html): 10-punktowa lista kontrolna audytu GA4 obejmujaca ustawienia uslugi, zdarzenia, konwersje, atrybucje, Consent Mode v2 i spojnosc z BigQuery. [Markdown](https://piotrlitwa.com/articles/md/pl/audyt-ga4-lista-kontrolna.md)
- [GA4 + BigQuery: Setup Guide and 10 Essential Queries for 2025](https://piotrlitwa.com/articles/en/ga4-bigquery-setup.html): GA4 BigQuery Export setup in 20 minutes plus 10 essential SQL queries every analyst needs. [Markdown](https://piotrlitwa.com/articles/md/en/ga4-bigquery-setup.md)
- [GA4 + BigQuery: Poradnik konfiguracji i 10 najważniejszych zapytań 2025](https://piotrlitwa.com/articles/pl/ga4-bigquery-konfiguracja.html): Konfiguracja GA4 BigQuery Export w 20 minut plus 10 kluczowych zapytań SQL, których potrzebuje każdy analityk. [Markdown](https://piotrlitwa.com/articles/md/pl/ga4-bigquery-konfiguracja.md)
- [BigQuery Costs Explained: How to Optimize GA4 Export Spending in 2025](https://piotrlitwa.com/articles/en/bigquery-cost-optimization.html): Seven BigQuery optimizations that cut typical GA4 Export costs by 60-90% plus billing alert setup. [Markdown](https://piotrlitwa.com/articles/md/en/bigquery-cost-optimization.md)
- [Koszty BigQuery: Jak zoptymalizować wydatki na GA4 Export w 2025](https://piotrlitwa.com/articles/pl/bigquery-koszty-optymalizacja.html): Siedem optymalizacji BigQuery, które tną typowe koszty GA4 Export o 60-90% plus ustawianie alertów billingowych. [Markdown](https://piotrlitwa.com/articles/md/pl/bigquery-koszty-optymalizacja.md)
- [BigQuery: What Is It? Complete Guide for Analysts in 2025](https://piotrlitwa.com/articles/en/bigquery-what-is-it-guide.html): Google's serverless data warehouse: what it is, pricing, when to use it for GA4, when not to. [Markdown](https://piotrlitwa.com/articles/md/en/bigquery-what-is-it-guide.md)
- [BigQuery: Co to jest? Kompletny poradnik dla analityków 2025](https://piotrlitwa.com/articles/pl/bigquery-co-to-jest-poradnik.html): Bezserwerowa hurtownia danych Google: czym jest, ile kosztuje, kiedy używać do GA4, a kiedy nie. [Markdown](https://piotrlitwa.com/articles/md/pl/bigquery-co-to-jest-poradnik.md)
- [Is Google Analytics Legal in Europe Under GDPR? 2025 Answer](https://piotrlitwa.com/articles/en/google-analytics-gdpr.html): Is GA4 legal in Europe today under the Data Privacy Framework, what could change, and what to do either way. [Markdown](https://piotrlitwa.com/articles/md/en/google-analytics-gdpr.md)
- [Czy Google Analytics jest legalne w Europie pod RODO? Odpowiedź na 2025](https://piotrlitwa.com/articles/pl/google-analytics-rodo.html): Czy GA4 jest legalne w Europie dziś pod Data Privacy Framework, co może się zmienić i co robić niezależnie. [Markdown](https://piotrlitwa.com/articles/md/pl/google-analytics-rodo.md)
- [Google Consent Mode V2: Complete Implementation Guide for 2025](https://piotrlitwa.com/articles/en/consent-mode-v2-guide.html): What Consent Mode V2 is, the 4 signals, Basic vs Advanced, and how to implement it with GTM. [Markdown](https://piotrlitwa.com/articles/md/en/consent-mode-v2-guide.md)
- [Google Consent Mode V2: Kompletny poradnik wdrożenia 2025](https://piotrlitwa.com/articles/pl/consent-mode-v2-jak-wdrozyc.html): Czym jest Consent Mode V2, cztery sygnały, Basic vs Advanced i jak wdrożyć z GTM. [Markdown](https://piotrlitwa.com/articles/md/pl/consent-mode-v2-jak-wdrozyc.md)
- [Cookiebot on WordPress: Install Guide + Free Alternative in 2025](https://piotrlitwa.com/articles/en/cookiebot-wordpress-install-guide.html): Step-by-step Cookiebot install on WordPress with Consent Mode v2, plus the free WP-native alternative. [Markdown](https://piotrlitwa.com/articles/md/en/cookiebot-wordpress-install-guide.md)
- [Cookiebot na WordPressie: Jak zainstalować + darmowa alternatywa 2025](https://piotrlitwa.com/articles/pl/cookiebot-wordpress-jak-zainstalowac.html): Instalacja Cookiebota na WordPress krok po kroku z Consent Mode v2 plus darmowa wtyczka natywna. [Markdown](https://piotrlitwa.com/articles/md/pl/cookiebot-wordpress-jak-zainstalowac.md)
- [Adobe Analytics API: Complete Guide to Reporting API 2.0 in 2025](https://piotrlitwa.com/articles/en/adobe-analytics-api-guide.html): Adobe's REST API for analytics data: OAuth auth, endpoints, rate limits, and BigQuery pipelines. [Markdown](https://piotrlitwa.com/articles/md/en/adobe-analytics-api-guide.md)
- [Adobe Analytics API: Kompletny poradnik po Reporting API 2.0 w 2025](https://piotrlitwa.com/articles/pl/adobe-analytics-api-poradnik.html): REST API Adobe do danych analitycznych: autoryzacja OAuth, endpointy, limity, pipeline'y BigQuery. [Markdown](https://piotrlitwa.com/articles/md/pl/adobe-analytics-api-poradnik.md)
- [Reactor API (Adobe Launch API): Complete Guide to AEP Tags Automation](https://piotrlitwa.com/articles/en/reactor-api-adobe-launch-api-guide.html): Adobe's REST API for AEP Tags: authentication, resources, rate limits, and CI/CD use cases. [Markdown](https://piotrlitwa.com/articles/md/en/reactor-api-adobe-launch-api-guide.md)
- [Reactor API (Adobe Launch API): Kompletny poradnik automatyzacji AEP Tags 2025](https://piotrlitwa.com/articles/pl/reactor-api-adobe-launch-api-poradnik.html): REST API Adobe do AEP Tags: autoryzacja, zasoby, limity i use case'y CI/CD. [Markdown](https://piotrlitwa.com/articles/md/pl/reactor-api-adobe-launch-api-poradnik.md)
- [AEP Tags Help: What an Independent Specialist Actually Does for Your Tag Management](https://piotrlitwa.com/articles/en/aep-tags-help.html): When to hire an AEP Tags specialist, what a tag management audit covers, typical costs (EUR 2-10K), and when GTM is the better choice. [Markdown](https://piotrlitwa.com/articles/md/en/aep-tags-help.md)
- [AEP Tags Help: Pomoc z Adobe Experience Platform Tags od Niezaleznego Specjalisty](https://piotrlitwa.com/articles/pl/aep-tags-pomoc.html): Kiedy zatrudnic specjaliste AEP Tags, co obejmuje audyt tag managementu, typowe koszty i kiedy GTM jest lepszym wyborem. [Markdown](https://piotrlitwa.com/articles/md/pl/aep-tags-pomoc.md)
- [Adobe Analytics Help: What an Independent Consultant Actually Does for You](https://piotrlitwa.com/articles/en/adobe-analytics-help.html): When to hire an Adobe Analytics consultant, what an implementation audit covers, typical costs (EUR 3-15K), and how to tell if your setup needs help. [Markdown](https://piotrlitwa.com/articles/md/en/adobe-analytics-help.md)
- [Adobe Analytics Help: Pomoc z Adobe Analytics od Niezaleznego Konsultanta](https://piotrlitwa.com/articles/pl/adobe-analytics-pomoc.html): Kiedy zatrudnic konsultanta Adobe Analytics, co obejmuje audyt wdrozenia, typowe koszty i jak ocenic czy Twoj setup potrzebuje pomocy. [Markdown](https://piotrlitwa.com/articles/md/pl/adobe-analytics-pomoc.md)
- [Looker Studio: What Is It and What Can You Do With It? Complete 2025 Guide](https://piotrlitwa.com/articles/en/looker-studio-what-is-it-guide.html): Google's free reporting tool guide covering dashboards, data sources, Power BI comparison, and practical tips. [Markdown](https://piotrlitwa.com/articles/md/en/looker-studio-what-is-it-guide.md)
- [Looker Studio: Co To Jest i Do Czego Sluzy? Kompletny Poradnik 2025](https://piotrlitwa.com/articles/pl/looker-studio-co-to-jest-poradnik.html): Darmowe narzedzie Google do raportow: dashboardy, zrodla danych, porownanie z Power BI i praktyczne wskazowki. [Markdown](https://piotrlitwa.com/articles/md/pl/looker-studio-co-to-jest-poradnik.md)
- [GTM Server-Side: What Is It and Why Does It Matter? 2025 Guide](https://piotrlitwa.com/articles/en/gtm-server-side-what-is-it-guide.html): Server-side tagging guide covering how it works, costs, benefits, and who needs it. [Markdown](https://piotrlitwa.com/articles/md/en/gtm-server-side-what-is-it-guide.md)
- [GTM Server-Side: Co To Jest i Dlaczego Jest Wazny? Poradnik 2025](https://piotrlitwa.com/articles/pl/gtm-server-side-co-to-jest-poradnik.html): Poradnik o server-side tagging: jak dziala, koszty, korzysci i kto tego potrzebuje. [Markdown](https://piotrlitwa.com/articles/md/pl/gtm-server-side-co-to-jest-poradnik.md)
- [Power BI: What Is It and How Does It Work? Complete 2025 Guide](https://piotrlitwa.com/articles/en/power-bi-what-is-it-complete-guide.html): Microsoft's BI platform guide covering dashboards, data sources, pricing, and Looker Studio comparison. [Markdown](https://piotrlitwa.com/articles/md/en/power-bi-what-is-it-complete-guide.md)
- [Power BI: Co To Jest i Jak Dziala? Kompletny Poradnik 2025](https://piotrlitwa.com/articles/pl/power-bi-co-to-jest-kompletny-poradnik.html): Poradnik o platformie BI Microsoft: dashboardy, zrodla danych, ceny i porownanie z Looker Studio. [Markdown](https://piotrlitwa.com/articles/md/pl/power-bi-co-to-jest-kompletny-poradnik.md)
- [Adobe Launch (AEP Tags): What Is It and How Does It Work? 2025 Guide](https://piotrlitwa.com/articles/en/adobe-launch-what-is-it-guide.html): Adobe's tag management system guide covering extensions, rules, GTM comparison, and publishing workflow. [Markdown](https://piotrlitwa.com/articles/md/en/adobe-launch-what-is-it-guide.md)
- [Adobe Launch (AEP Tags): Co To Jest i Jak Dziala? Poradnik 2025](https://piotrlitwa.com/articles/pl/adobe-launch-co-to-jest-poradnik.html): Poradnik o systemie zarzadzania tagami Adobe: rozszerzenia, reguly, porownanie z GTM i workflow publikacji. [Markdown](https://piotrlitwa.com/articles/md/pl/adobe-launch-co-to-jest-poradnik.md)
- [Adobe Analytics: What Is It and How Does It Work? Complete 2025 Guide](https://piotrlitwa.com/articles/en/adobe-analytics-what-is-it-complete-guide.html): Enterprise analytics platform guide covering features, GA4 comparison, pricing, and implementation. [Markdown](https://piotrlitwa.com/articles/md/en/adobe-analytics-what-is-it-complete-guide.md)
- [Adobe Analytics: Co To Jest i Jak Dziala? Kompletny Poradnik 2025](https://piotrlitwa.com/articles/pl/adobe-analytics-co-to-jest-kompletny-poradnik.html): Poradnik o platformie analitycznej enterprise: funkcje, porownanie z GA4, wdrozenie i ceny. [Markdown](https://piotrlitwa.com/articles/md/pl/adobe-analytics-co-to-jest-kompletny-poradnik.md)
- [Google Analytics 4: What Is It and How Does It Work? Complete 2025 Guide](https://piotrlitwa.com/articles/en/google-analytics-4-what-is-it-how-it-works.html): Comprehensive guide to GA4 - what it is, event-based tracking, key reports, setup steps, and common mistakes. [Markdown](https://piotrlitwa.com/articles/md/en/google-analytics-4-what-is-it-how-it-works.md)
- [Google Analytics 4: Co To Jest i Jak Dziala? Poradnik 2025](https://piotrlitwa.com/articles/pl/google-analytics-4-co-to-jest-jak-dziala.html): Kompletny poradnik GA4 po polsku - czym jest, model zdarzen, kluczowe raporty, instalacja i czeste bledy. [Markdown](https://piotrlitwa.com/articles/md/pl/google-analytics-4-co-to-jest-jak-dziala.md)
- [5 GTM Mistakes That Are Silently Costing You Conversions](https://piotrlitwa.com/articles/en/5-gtm-mistakes-costing-you-conversions.html): The five most common GTM misconfigurations found during audits and how to fix them. [Markdown](https://piotrlitwa.com/articles/md/en/5-gtm-mistakes-costing-you-conversions.md)
- [5 bledow GTM, ktore po cichu kosztuja Cie konwersje](https://piotrlitwa.com/articles/pl/5-bledow-gtm-ktore-kosztuja-konwersje.html): Najczestsze bledy konfiguracji GTM i jak je naprawic. [Markdown](https://piotrlitwa.com/articles/md/pl/5-bledow-gtm-ktore-kosztuja-konwersje.md)

## Product Documentation

Each product × platform combination has its own stable URL so it can be shared with platform reviewers or linked from marketplace listings. Polish versions live under `/pl/docs/products/...` with hreflang linking.

- [Documentation Hub](https://piotrlitwa.com/docs/products/) - all products and their per-platform integration guides.
- [Purchase & E-commerce DataLayer](https://piotrlitwa.com/docs/products/purchase.html): Full e-commerce events (purchase, cart, checkout, product impressions). Server-side webhooks + GA4-ready dataLayer. Unified format across platforms.
- [Meta Conversions API (CAPI)](https://piotrlitwa.com/docs/products/meta-capi.html): Server-side Meta/Facebook event tracking via Graph API v21.0. SHA256 hashing, EMQ 8/10+, Polish diacritics handling.
- [Google Product Feed](https://piotrlitwa.com/docs/products/google-feed.html): Product data sync to Google Merchant Center via Content API v2.1.
- [Facebook Product Feed](https://piotrlitwa.com/docs/products/facebook-feed.html): Facebook/Instagram catalog sync via Marketing API v21.0 for dynamic ads.
- [Server-Side Tracking (S2S)](https://piotrlitwa.com/docs/products/s2s.html): Universal server-to-server event forwarder with configurable authentication.
- [First Party Data Collection](https://piotrlitwa.com/docs/products/fpd.html): Unified customer profiles from purchase events; your own first-party data warehouse.
- [Consent Management Module](https://piotrlitwa.com/docs/products/consent.html): Google Consent Mode v2 integration with GDPR audit logging.
- [AI Visibility](https://piotrlitwa.com/docs/products/ai-visibility.html): Product purchase signals for AI-powered recommendations and visibility optimization.

## Contact

- Website: https://piotrlitwa.com
- LinkedIn: https://linkedin.com/in/piotr-litwa
- GitHub: https://github.com/piotrlitwa

## Expertise

Google Tag Manager, GA4, Consent Mode v2, Server-Side Tagging, BigQuery, Google Ads conversion tracking, Meta Conversions API, data layer architecture, cookie compliance, GDPR, analytics accuracy, agency accountability.