Job Description

We are looking for a senior full-stack developer to help build and scale SMSNinja, a modern messaging platform designed for charities and fundraising teams.

SMSNinja combines two-way SMS, AI-assisted reply drafting, and team review workflows to help organisations manage supporter conversations more effectively. We are rebuilding the platform on a modern multi-tenant architecture and need an experienced developer who can help turn a strong foundation into a reliable production product.

This is a hands-on role for someone who is comfortable working across frontend, backend, database design, third-party integrations, and production delivery.

Key Responsibilities

- Build new product features across the messaging inbox, admin tools, and settings flows
- Improve and extend AI-assisted workflows for drafting and reviewing SMS replies
- Develop background job and processing flows for async tasks, retries, and syncing
- Integrate and harden webhook-driven systems such as Twilio
- Design and ship database migrations to support current functionality safely
- Improve reliability, observability, and operational safety across the platform
- Support fundraising-related integrations and related product workflows
- Help shape the product architecture as the platform grows

Skill & Experience





- Strong experience building production web applications with TypeScript and React
- Comfortable using AI to increase workflow velocity
- Strong experience with Next.js
- Confidence working on both frontend product work and backend application logic
- Solid experience with relational databases, schema design, and migrations
- Experience integrating third-party APIs and webhook-based systems
- Ability to debug production issues and ship pragmatic fixes quickly
- Comfortable owning work end to end, from implementation through rollout
- Advantage if have these skills:
- Experience with Supabase
- Experience with Twilio or other messaging platforms
- Experience with queue or job processing systems
- Experience building multi-tenant SaaS products
- Experience working with AI-powered product features
- Experience in fundraising, nonprofit tech, CRM, or supporter engagement tools

- You’re likely a strong fit if you:

- enjoy building real products, not just prototypes
- can move between UI, APIs, data modeling, and infrastructure concerns
- are pragmatic, fast, and technically rigorous
- are comfortable in an evolving product environment
- like taking ownership of meaningful product and platform work

📌 Senior Full-Stack Developer (Sydney)
🏢 Digital Ninjas
📍 Sydney