What are the responsibilities and job description for the Senior Software Engineer position at twentyAI?
Senior Software Engineer (Full-stack)
New York City (Onsite)
$160,000 - $200,000 meaningful equity
No sponsorship available at this time
About the Company
Our client is a seed-stage, venture-backed startup building modern software for investment and finance teams. They’re creating a new product line focused on transforming complex, granular data into tools customers actively rely on to run their businesses. The team is small, highly motivated, and operating with a strong builder mindset as they scale their platform and customer base.
About the Role
This hire will be the first dedicated engineer focused on a brand-new product area inside the company. You’ll work directly with senior leadership and engineering to build an entirely new business line from the ground up.
It’s a high-autonomy role suited to someone who enjoys ownership, ambiguity, and startup pace. You’ll be expected to think like a mini founder, making technical and product decisions, shipping quickly, and laying foundations that will scale as the team grows.
What You’ll Do
- Design and build backend-heavy full-stack systems powering a new product
- Ingest, normalise, and structure complex, data-heavy inputs
- Build APIs and services that aggregate and reconcile large datasets
- Develop analytics and reporting tools customers are explicitly asking for
- Make clear trade offs between speed, scalability, and correctness
- Work closely with leadership to shape product direction and execution
- Help lay the groundwork for scaling the product and future hires
Requirements
- 4 years of professional software engineering experience
- Computer Science degree or equivalent technical background
- Strong backend experience with Python (FastAPI or similar)
- Experience with React and TypeScript on the frontend
- Solid understanding of data-heavy systems and API design
- Experience working in AWS or similar cloud environments
- Comfortable operating in small teams with high ownership
- Startup experience strongly preferred, fintech experience not required
Why Join
- Rare opportunity to build a core product line from zero inside a growing company
- Direct ownership over a product that is already driving customer demand and revenue
- Work closely with senior leadership and influence both technical and product direction
- High-trust environment with real autonomy and responsibility from day one
- Strong backing and clear long-term upside as the product and team scale
Salary : $160,000 - $200,000