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 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.

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

Solid 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

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 setting 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.

To Apply

Please apply using the form below and include:

– a short introduction

– links to relevant projects or GitHub work

– a summary of your experience with Next.js, TypeScript, and backend/product delivery

– any relevant experience with messaging, AI workflows, or fundraising/nonprofit platforms

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