Full-Time Founding Engineer Needed for Live SaaS Product — React, Next.js, Firebase, Analytics

We are looking for a **full-time freelance full-stack engineer** to take ownership of a live SaaS product with real paying users. The product helps businesses track WhatsApp conversations and attribute them back to paid advertising campaigns such as Google Ads. It is used by businesses, agencies, and performance marketers in markets where WhatsApp is a primary sales and support channel. This is a **long-term contract role**, not a short bug-fixing task. We are looking for someone available **30–40 hours per week** who can work directly with the founder and take ownership of the product’s engineering, analytics, and user journey. ## Product Status The product has been live since May 2025 and already has paying users. The current codebase was built by a previous contract team. We now need one strong engineer to understand the existing system, stabilise it, improve the product experience, and help us build the next stage of the platform. ## First Priority: Analytics, Observability, and User Journey PostHog and Sentry are already implemented, but we are not confident that the setup is correct. Your first responsibility will be to audit and improve the existing analytics and monitoring setup. You will: * Audit the current PostHog implementation * Audit the current Sentry setup * Validate which events are being tracked correctly * Fix broken, duplicate, missing, or misconfigured events * Properly instrument onboarding and user journey tracking * Identify where users drop off, stall, or abandon onboarding * Separate actual product bugs from UX friction * Recommend improvements based on churn, retention, activation, and user impact * Help connect insights to lifecycle messaging through Customer.io or Intercom where useful We are not looking for someone who only gives status updates. We want someone who can investigate, analyse, and bring a clear point of view. ## Ongoing Responsibilities After the analytics and observability work is stable, you will help with: * Bug fixes and UI improvements * Code review and cleanup * Improving performance * Reducing technical debt * Improving dev, staging, and production workflows * Adding acceptance testing and automated validation * Preventing production releases from breaking existing functionality * Researching and building third-party integrations Future integrations may include Zapier, HubSpot, Zoho, OAuth-based tools, and other CRM or marketing platforms. Current integrations include Google Ads and Google Sheets. ## Tech Stack You should be comfortable with: * React * Next.js * Firebase * Google Cloud Platform * Cloud Functions * PostHog or similar analytics tools * Sentry or similar error monitoring tools * Stripe * Vercel Bonus experience: * WhatsApp Business API / WhatsApp BSPs * Meta Business Suite * Google Ads API * Google Sheets API * Customer.io * Intercom * HubSpot, Zoho, Zapier, or OAuth integrations WhatsApp Business API or BSP experience is a major plus. ## Who We Are Looking For We are looking for someone who is: * Independent and proactive * Comfortable owning an inherited codebase * Strong in React, Next.js, Firebase, and serverless backends * Product-minded, not just ticket-focused * Analytical and able to find user journey problems * Comfortable making recommendations, not just completing assigned tasks * Clear and direct in communication * Experienced with real production software * Actively using AI tools to move faster in development You should be able to take a direction, investigate, decide what matters, and execute. ## Requirements Please apply only if you have: * 1+ year of production engineering experience * Strong hands-on React and Next.js experience * Firebase / GCP / Cloud Functions experience * Experience with product analytics tools such as PostHog, Mixpanel, Amplitude, or similar * Experience debugging production issues * Availability for 30–40 hours per week * Interest in a long-term freelance contract ## First 30 Days In the first month, the main goal will be to: 1. Understand the current product and codebase 2. Audit PostHog and Sentry 3. Fix analytics and error-tracking issues 4. Map the onboarding and user journey 5. Identify user drop-offs and product friction 6. Recommend the highest-impact product and engineering fixes 7. Start improving release safety between dev, staging, and production Generic applications will be ignored. We are looking for someone who can think independently and take ownership.