Senior Full-Stack Developer

Location: Australia

Type: Full-time

About The Role

We are looking for a senior full-stack developer to help build and scale SMSNinja, a contemporary 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.

What You’ll Work On

- 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 new 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

Our Stack

- Next.js
- React
- TypeScript
- Supabase
- PostgreSQL / SQL migrations
- Tailwind CSS
- Twilio
- OpenAI APIs
- Vercel

What We’re Looking For

- 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

Strong Advantages

- 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

What Success Looks Like

In this role, you’ll help take an already-started platform and move it forward through the next phase of delivery. That means shipping reliably, improving system quality, and making sound product and technical decisions without creating unnecessary complexity.

You should be someone who can:

- work independently
- make sensible technical tradeoffs
- communicate clearly
- keep momentum without cutting corners on important platform concerns like auth, tenant isolation, and integration reliability

Ideal Profile

- 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

Engagement

Open to contract, fractional, or the right longer-term arrangement depending on fit and availability.

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