Full Stack Engineer

About the role

WAct is looking for a full‑stack engineer to improve and maintain its SaaS platform that tracks WhatsApp conversions for performance marketers. You will work directly with the founder, own the product backlog and turn data‑driven insights into fast, reliable releases.

Key responsibilities

• Monitor user behavior with PostHog to spot bugs and retention problems.
• Identify drop‑off points, design UX improvements and ship fixes based on data.
• Build and maintain integrations with Google Ads API, Stripe, WhatsApp Business Service Provider APIs and Customer.io.
• Set up observability: error monitoring (Sentry), uptime alerts and structured logging.
• Deploy updates via Vercel and manage cloud functions on Firebase/GCP.
• Prioritise weekly work together with the founder and take ownership of the product roadmap.

Required profile

• Experience shipping production React/Next.js applications and working with Firebase or a comparable backend.
• Proven use of analytics tools (PostHog, Mixpanel, Amplitude) to drive product decisions.
• Business‑oriented mindset with the ability to prioritize features that improve user retention.
• Comfortable owning a codebase alone and debugging unfamiliar code.
• Self‑starter who proposes plans and works with minimal supervision.
• Clear written communication in an async‑first, founder‑led environment.

Required skills

• React
• Next.js
• Firebase / Google Cloud Platform (Cloud Functions)
• PostHog
• Stripe
• Customer.io
• Sentry
• Vercel
• Google Ads API
• WhatsApp Business API / BSP providers