Lead Full-Stack Engineer — AI Agents & SaaS

About the role

We are building an AI-powered SaaS platform combining conversational agents, knowledge retrieval, document workflows, and analytical tools.

We are looking for a hands-on engineering lead to own technical design and delivery across our web applications and AI agent systems. You will work directly with the founder and product stakeholders, make architectural decisions, implement features, and guide other engineers.

This is a software engineering role focused on AI agent development and full-stack web application development. It does not involve machine learning research, model training, fine-tuning, or developing ML algorithms.

Expect approximately 80–90% of your time to involve implementation, debugging, testing, and code review, with the remainder focused on architecture and planning.

Mandatory experience — please read before applying

Applicants must meet both requirements below.

1. Production LLM integration and AI agent development

You must have personally built and deployed LLM-powered agents in a production application. Your experience must include tool/function calling or multi-step agent workflows, with responsibility for implementation and production behaviour.

You should be able to explain:

• How the agent interacted with tools, APIs, and application data.
• How you managed execution state, context, or memory.
• How you handled failures, retries, and unexpected model responses.
• How you evaluated agent behaviour and managed latency and usage costs.
• Which components you personally designed and implemented.

Using AI coding assistants, completing courses, building tutorial projects, or implementing a basic chatbot wrapper alone does not satisfy this requirement.

2. Demonstrable experience in at least ONE of these areas

• Mobile application launch: Substantial engineering contribution to an Android or iOS application released on Google Play or the Apple App Store. You can explain your contribution to development, release, and post-launch operation.
• FinTech application development: Substantial engineering contribution to a production application involving payments, lending, banking, investments, trading, insurance, or financial operations. You can explain the financial workflows you implemented and how you addressed correctness, security, and reliability.

Experience in either area qualifies. Prior mobile experience is a delivery credential; the primary work in this position is web applications and AI agents.

What you will do

• Own features from requirements and technical design through implementation, release, and production support.
• Build responsive web interfaces, backend services, APIs, and PostgreSQL data models.
• Develop agents using existing LLM APIs, including tool execution, multi-step workflows, streaming responses, and context management.
• Implement document ingestion and retrieval-augmented generation to support agent workflows.
• Build reliable background processing with retries, recovery, and protection against duplicate execution.
• Make architectural decisions across the customer application, administration tools, AI runtime, and shared services.
• Maintain secure authentication, authorization, and data-access boundaries.
• Improve testing, observability, performance, deployment reliability, and operating costs.
• Develop dependable billing integrations and usage tracking.
• Review code, mentor engineers, and document significant technical decisions.
• Work independently in an existing codebase and improve it incrementally.

Required qualifications

• 7+ years of professional software engineering experience.
• Strong hands-on TypeScript and JavaScript skills across frontend and backend development.
• Production experience with React, preferably Next.js, and backend API development.
• Strong PostgreSQL knowledge, including schema design, transactions, indexing, and query optimization.
• Production LLM integration and agent-development experience meeting the requirement above.
• Mobile application launch or FinTech development experience meeting the requirement above.
• Experience deploying and supporting cloud applications, asynchronous workflows, and third-party integrations.
• Practical knowledge of application security, automated testing, CI/CD, and production troubleshooting.
• Demonstrated ownership of architecture and delivery for a substantial feature or system.
• Clear written and verbal communication, …