Full Stack Software Engineer - Agentic AI Startup

Join NinjaTech AI as a Full Stack Software Engineer to build the future of autonomous AI agents : technology that doesn't just assist, but actually executes complex tasks end-to-end.

You will learn and use the latest tech to innovate, build and scale intelligent Apps and automations (B2B and B2C), powered by SuperNinja - our advanced agentic AI platform with full OS capabilities. For this role we will prioritize candidates who have strong experience in Frontend development (in React, Next.js).

Why this opportunity is exciting :

First FE-Leaning Engineer at HQ : you will work side-by-side with expert-level Full stack engineers

Founding Team Impact : Work directly with founding engineering team (mostly ex-AWS) and ex-Google Product / UX leaders

Cutting-Edge AI : Build infrastructure, OS and UI for autonomous AI agents that can actually do things end to end (intelligent Apps and automations)

High Velocity, High Impact : Ship features that millions of users will interact with (B2C and B2B)

Technical Ownership : Own significant parts of the product architecture and make decisions that will scale with the company!

About the Company :

NinjaTech AI is a generative AI startup with headquarters in Silicon Valley and a subsidiary in Sydney. NinjaTech AI is backed by Alexa Fund and Samsung Ventures and we are on track to raise Series A funding in 2026.

About the Role :

The Full Stack Engineer is a full-time position, based at our HQ office in Los Altos, California ( 5 days on-site ; great office space, free daily meals). Our team works in a fast-paced and collaborative environment. We get a lot done when we ideate together and iterate quickly.

As a Software Development Engineer, you'll design and build user-facing features as well as back-end infrastructure that make our autonomous AI agents accessible, fast and powerful. You will report to the VP of Engineering and will collaborate on a daily basis with the founder / CEO and the VP of Product.

What you will build :

As a key member of our engineering team , the Software Engineer will be responsible for translating our vision and customer needs into functional and appealing interactive applications, ensuring a great user experience.

Develop and implement serving architecture for our distributed systems with focus on scalability, observability, and efficiency

Design and build components for internal SDKs for services and integrate them in collaboration with other developers

Write robust and well-documented code, ensuring quality through automated testing and continuous integration and deployment

Work effectively in a fast-paced, dynamic team environment, contributing to multiple projects

Conduct code reviews and provide constructive feedback to other members of the team

Develop and maintain documentation for the platform, including API documentation, technical guides, and technical specifications

Explore new tools and technologies that can improve development efficiency and product quality

Required Experience :

3+ years of experience in software development, with a focus on building scalable and reliable web applications.

Expert-level experience in React.

Proficiency in Next.js and Python.

Experience with AWS Cloud.

Strong expertise in various API protocols, including RESTful API and WebSockets.

Familiarity with database technologies such as Firebase, Supabase, DynamoDB, NoSQL, PostgreSQL, or MySQL.

Hands-on experience in building microservices for service-oriented architecture (SoA) on top of AWS services, leveraging various components (e.g., SQS, Lambda, SNS, ECS, etc.).

In-depth understanding of the entire web development process (design, development and deployment).

Familiarity with RESTful APIs and integration of backend services.

Knowledge of version control systems (e.g., Git) and experience working with collaborative development tools.

Ability to perform well in a fast-paced environment where deadlines are tight and priorities can change rapidly.

Strong problem-solving skills and ability to work in a team environment.

Preferred Qualifications :

Bachelor's or Master's degree in Computer Science or Engineering

Experience with Large language models (LLMs) and AI agent frameworks, as well as machine learning model deployment and serving

Knowledge of real-time systems and WebSocket / streaming protocols

Experience with infrastructure as code (CDK, Terraform, CloudFormation)

Experience in a high-growth startup environment

Experience with observability tools (Grafana, DataDog)

Benefits :

Excellent Health insurance plans

401(k)

Generous Paid Time Off (Vacation, Sick & Holidays)

Paid meals and snacks

Equity grants (we are still pre-Series A so it's a great time to join the founding team!)