Synthetic AI is building an autonomous AI system that replaces traditional bookkeeping services for small and medium-sized businesses. The Staff / Principal Software Engineer will join the founding engineering team to build AI agents, financial integrations, accounting infrastructure, and full-stack product systems while owning major technical projects and architectural decisions.

Responsibilities:

Build and enhance AI agents capable of autonomously handling end-to-end bookkeeping workflows
Develop AI-powered systems that automate complex financial operations for SMB customers
Own financial provider integrations with platforms such as Ramp, Brex, and Gusto
Take financial integrations from initial scoping through production deployment
Design and build the company's accounting ledger from the ground up
Architect core financial data infrastructure supporting bookkeeping workflows
Build reliable systems for financial data ingestion, processing, reconciliation, and reporting
Ship new product features rapidly across the full stack using TypeScript and Next.js
Work across frontend and backend systems with an approximately 60/40 frontend-to-backend split
Build and improve LLM-powered workflows and AI/ML infrastructure
Integrate AI agents with financial systems and customer workflows
Work directly with test customers to understand product requirements and workflow pain points
Collaborate directly with integration partners and financial technology providers
Translate customer feedback into product and engineering decisions
Own major technical projects from concept through production
Identify high-impact engineering problems independently and execute solutions with minimal direction
Make architecture and technical decisions across product, backend, financial infrastructure, and AI systems
Build reliable production systems capable of handling sensitive financial workflows
Help define the technical direction of the founding engineering organization
Operate with extreme ownership in a highly iterative startup environment

Requirements:

- 5+ years of professional software engineering experience
- Strong experience building production software systems
- Experience owning complex technical projects end-to-end
- Experience working across both frontend and backend systems
- Experience building AI-powered or AI-native products
- Experience integrating third-party APIs and financial platforms
- Experience working in early-stage or high-growth startups
- Strong product engineering experience with significant ownership
- Experience operating independently without extensive processes or management
- Strong track record of shipping production features quickly
- Strong builder mentality and willingness to work across the entire product stack
- Expert-level TypeScript experience
- Strong Next.js and Node.js experience
- Strong full-stack software engineering fundamentals
- Experience building production backend systems
- Experience building LLM-powered applications or AI agents
- Experience integrating AI/ML capabilities into production products
- Experience designing APIs and third-party integrations
- Strong database and data modeling experience
- Experience designing reliable production systems
- Strong understanding of distributed systems and backend architecture
- Experience with modern AI/LLM tooling
- Experience building autonomous workflows or agentic systems
- Strong software architecture and system design capabilities
- Ability to write clean, maintainable production code
- Experience with Node.js and modern JavaScript/TypeScript infrastructure
- Strong computer science and software engineering fundamentals
- Equivalent practical engineering experience accepted
- Exceptional engineering ownership
- Extremely high execution velocity
- Strong product intuition
- Excellent problem-solving ability
- Comfortable operating independently
- Comfortable working without extensive direction
- Strong customer empathy
- Excellent communication skills
- Comfortable speaking directly with customers and integration partners
- Strong startup mentality
- Bias toward action
- Willingness to work across frontend, backend, AI, and infrastructure
- Comfortable with rapidly changing priorities
- Strong technical judgment
- Low-ego collaborative mentality
- Passion for building AI-native products
- Comfortable working in an extremely small engineering organization
- Willingness to operate at high intensity
- Experience working with financial systems, fintech, accounting, or financial APIs preferred
- Experience working directly with customers or external partners preferred
- Experience with financial APIs or fintech infrastructure preferred
- Experience building financial data systems, ledgers, or accounting infrastructure preferred
- Experience working with LLMs, AI/ML systems, or agent orchestration preferred
- Bachelor's degree or higher in Computer Science, Engineering, Mathematics, or related technical field preferred
- Strong technical depth in systems, backend engineering, AI, or financial infrastructure preferred

Staff/Principal Software Engineer

Key skills

About this role

Responsibilities:

Requirements: