11/01/2026 updated
DM
100 % available
Senior Tracking & Analytics Engineer
Valencia, Spain
Only remote
Master's degree, Public Relations, Advertising and Applied CommunicationAbout me
I fix and rebuild measurement when purchases go missing, conversions get counted twice or reports don't match real orders. 13 years of independent practice, 547 Upwork jobs, Top Rated. Founder of Fixel Pixel, a server-side event product for Shopify. Remote from Valencia (CET), B2B.
Tracking & Tagging
Expertise in Google Tag Manager (web and server-side), GA4 including Measurement Protocol, Admin API and BigQuery export, Stape, Tealium iQ, self-hosted sGTM, dataLayer and tracking plans, Consent Mode v2 with CookieYes and Cookiebot, GPC, and cross-domain tracking.
Ad Platforms & Conversion APIs
Deep knowledge of Meta Pixel and Conversions API (dedup, EMQ), Google Ads enhanced and offline conversions, Ads API, Data Manager API, Microsoft Ads UET, TikTok, Pinterest, Merchant Center, Meta SDK, and SKAdNetwork for iOS.
Shopify & E-Commerce Development
Proficiency in Shopify and Shopify Plus including Admin GraphQL, Storefront API, Web Pixels, Checkout UI extensions, Functions, Carrier Service, Billing API, Liquid, App Bridge, Polaris, and headless setups; also Magento 2, WordPress, and Webflow.
Analytics & Data
Hands-on experience with SQL, BigQuery, dbt, Adobe Analytics, Amplitude, Looker Studio, Apps Script, Triple Whale, Clarity, Hotjar, order-by-order reconciliation, attribution analysis, statistical testing, A/B and MVT.
CRM, Payments & Automation
Integration experience with Stripe (webhooks, subscriptions), PayPal, Klarna, Shop Pay, HubSpot, Zoho, GoHighLevel, Klaviyo, Customer.io, Calendly, cal.com, n8n, Zapier, REST, GraphQL, and webhook integrations.
Programming Languages
Proficiency in TypeScript, JavaScript (Node.js), Python, SQL, Go, Bash, PHP, Liquid, Dart (Flutter), and HTML/CSS.
Frameworks & Libraries
Experience with React, Remix and React Router 7, Next.js, Astro, Fastify, Express, FastAPI, aiogram, grammY, Prisma, Zod, BullMQ, TanStack Query, Tailwind, Vite, and Turborepo.
Databases & Queues
Working knowledge of PostgreSQL, ClickHouse, Redis with BullMQ, SQLite (FTS5), MySQL and MariaDB, BigQuery, S3, and MinIO.
Infrastructure
Practical experience with Linux, Docker, Kubernetes, nginx, Caddy, Cloudflare (Workers, DNS, load balancing), Terraform, Google Cloud, GitHub Actions, Prometheus, Grafana, Loki, Sentry, OpenBao, and WireGuard.
Testing & QA
Use of Vitest, Jest, Playwright for capture harness, contract and end-to-end tests, acceptance conditions, negative tests, Core Web Vitals checks, and a rollback for every change.
AI Engineering
Application of Claude and OpenAI APIs, tool-calling agents with evals, MCP servers, LLM intake with human review, and multi-agent coding pipelines using Claude Code and Codex.
Expertise in Google Tag Manager (web and server-side), GA4 including Measurement Protocol, Admin API and BigQuery export, Stape, Tealium iQ, self-hosted sGTM, dataLayer and tracking plans, Consent Mode v2 with CookieYes and Cookiebot, GPC, and cross-domain tracking.
Ad Platforms & Conversion APIs
Deep knowledge of Meta Pixel and Conversions API (dedup, EMQ), Google Ads enhanced and offline conversions, Ads API, Data Manager API, Microsoft Ads UET, TikTok, Pinterest, Merchant Center, Meta SDK, and SKAdNetwork for iOS.
Shopify & E-Commerce Development
Proficiency in Shopify and Shopify Plus including Admin GraphQL, Storefront API, Web Pixels, Checkout UI extensions, Functions, Carrier Service, Billing API, Liquid, App Bridge, Polaris, and headless setups; also Magento 2, WordPress, and Webflow.
Analytics & Data
Hands-on experience with SQL, BigQuery, dbt, Adobe Analytics, Amplitude, Looker Studio, Apps Script, Triple Whale, Clarity, Hotjar, order-by-order reconciliation, attribution analysis, statistical testing, A/B and MVT.
CRM, Payments & Automation
Integration experience with Stripe (webhooks, subscriptions), PayPal, Klarna, Shop Pay, HubSpot, Zoho, GoHighLevel, Klaviyo, Customer.io, Calendly, cal.com, n8n, Zapier, REST, GraphQL, and webhook integrations.
Programming Languages
Proficiency in TypeScript, JavaScript (Node.js), Python, SQL, Go, Bash, PHP, Liquid, Dart (Flutter), and HTML/CSS.
Frameworks & Libraries
Experience with React, Remix and React Router 7, Next.js, Astro, Fastify, Express, FastAPI, aiogram, grammY, Prisma, Zod, BullMQ, TanStack Query, Tailwind, Vite, and Turborepo.
Databases & Queues
Working knowledge of PostgreSQL, ClickHouse, Redis with BullMQ, SQLite (FTS5), MySQL and MariaDB, BigQuery, S3, and MinIO.
Infrastructure
Practical experience with Linux, Docker, Kubernetes, nginx, Caddy, Cloudflare (Workers, DNS, load balancing), Terraform, Google Cloud, GitHub Actions, Prometheus, Grafana, Loki, Sentry, OpenBao, and WireGuard.
Testing & QA
Use of Vitest, Jest, Playwright for capture harness, contract and end-to-end tests, acceptance conditions, negative tests, Core Web Vitals checks, and a rollback for every change.
AI Engineering
Application of Claude and OpenAI APIs, tool-calling agents with evals, MCP servers, LLM intake with human review, and multi-agent coding pipelines using Claude Code and Codex.
Experience
Professional experience10+ years
Freelancer since2013
Languages
EnglishFluentRussianNative speakerSpanishGood
Project history
Built Fixel Pixel, a Shopify measurement product capturing storefront and checkout events and delivering them to Meta Conversions API, GA4 and Google Ads. Designed shared browser-server event identity and per-attempt delivery records. TypeScript monorepo on PostgreSQL, ClickHouse, Redis/BullMQ and Fastify with 2,950 commits since Nov 2025; self-managed Linux and Docker production. Built DeploTeka for provisioning and operating one dedicated Shopify app per store across the product fleet.
Serving ecommerce stores, lead-generation businesses, SaaS companies and agencies in the UK, US and EU via Upwork (Top Rated) and taskfordaniel.com. Every job includes agreed acceptance checks, test evidence and handover notes. Projects include rebuilding measurement for headless Shopify retailers, reconciling multi-currency fashion brands, fixing GA4 coverage for DTC brands, tracing Stripe subscriptions as offline conversions, writing event contracts for online marketplaces, statistical attribution analysis, and Core Web Vitals optimisation.
Conversion tracking and measurement setup, A/B and MVT experiment planning, hypotheses and reporting. Remote.