Senior Software Engineer (React, Next.js, Python) - Agentic AI Startup

We invite you to join NinjaTech AI as a Senior Software Engineer as we innovate together to build autonomous AI agents. For this role we will prioritize candidates who are leaning Frontend development (in React, Next.js). This is an onsite position designed to build web applications and agentic AI systems with our strong ex-AWS founding engineering team.

About the Company :

NinjaTech AI is a generative AI startup (B2C and B2B) with headquarters in Silicon Valley and offices in Sydney and Vancouver. Our all-in-one AI assistant, Ninja, combines the best AI models and custom AI agents to empower our customers to quickly complete tasks across research, writing, coding, image generation, and more (think of an AI agent placing orders online, making reservations or building websites for you by accessing your phone apps or installing software on a virtual computer for you when needed to complete a task).

NinjaTech AI is backed by Alexa Fund and Samsung Ventures and we are on track to raise Series A funding in 2025.

About the Role :

The Senior Software 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. Our velocity, scientific rigor and engineering excellence are exceptional.

The Senior Software Engineer will design, develop, integrate and deploy various AI technologies within NinjaTech’s Agentic AI product. You will report to the VP of Engineering (ex-AWS, onsite in Sydney) and will collaborate with the Chief Science and Technology Officer / Co-founder (also ex-AWS; onsite in Sydney) as well as our a remarkable team of Software Engineers and Applied Scientists, UX, QA and product managers.

What you will do :

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

Build features for our web app ( myninja.ai and https : / / super.myninja.ai)

Bring expertise in performance and optimization to improve our applications for smooth and fast user experience.

Develop and maintain documentation for the platform, including API documentation.

Write clean, efficient, and well-documented code in React, Next.js, Python and ensure code quality through automated testing and continuous integration and deployment.

Participate in code reviews and provide constructive feedback to other members of the team.

Troubleshoot and debug issues that arise in the platform, and implement solutions to prevent recurrence.

Collaborate with product management to define and prioritize product requirements, ensuring technical feasibility and alignment with company goals and user requests.

Leverage RESTful APIs and web sockets for fast communication with our backend systems.

Unit-test code for robustness, including edge cases, usability, and general reliability.

Continuously discover, evaluate, and implement new technologies to maximize development efficiency.

Required Experience :

5+ 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.

Experience working in an Agile development environment.

Bachelor's or Master's degree in Computer Science or relevant field preferred.

Benefits :

Excellent Health insurance plans

401k

Generous Paid Time Off (Vacation, Sick & Holidays)

Paid meals and snacks

Equity grants