Senior Software Engineer

Ersilia; San Francisco (CA); Hybrid; USD 180,000 - 240,000; Full time

Job summary

Ersilia is hiring a Senior Full-stack Engineer to own large parts of the product from ideation to implementation. You will balance frontend (React/TypeScript) and backend (Python/Flask) work while building AI-powered creator tools, collaborating with AI PMs and ML engineers, and shaping what AI can do in product.

You will lead frontend development with a strong focus on UI/UX and create scalable systems that handle millions of page views daily, with the goal of reaching billions as the platform

Qualifications

• 5+ years of full-stack engineering experience.
• AI-native work style with concrete examples from the last 6 months.
• Proficient in TypeScript and Python for frontend/backend.
• Based in SF or NY, hybrid in-office Tue–Thu.
• Experience with SQL and Postgres.

Responsibilities

• Build and iterate on AI-powered creator tools with AI PMs and ML engineers.
• Scale products to billions of views and ensure frontend excellence.
• Lead frontend development with delightful UI/UX.
• Create systems and understand how components interact.
• Apply AI as the default approach from scoping to code review.

Skills

Full-stack

AI-native

TypeScript

Python

SQL

Postgres

Customer empathy

Ambiguity tolerance

Tools

Cursor

Copilot

Claude Code

LLM tooling

Job description

About Us

We have the easiest way to build a website that your fans will love! We help creators centralize their online brand presences, connect with their audiences and partners in a streamlined way, and better understand how to build and improve their businesses. We're excited to tackle the rapidly growing, $200 billion creator economy. There's a huge opportunity to help creators build the businesses of tomorrow, and we're positioned to build the defining solution.

How the Team Works

AI is a core part of how the engineering team operates: not a productivity hack, but a fundamental shift in how the team scopes, builds, and ships. The team uses AI coding assistants in production workflows, LLMs for planning and spec-writing, and agentic tools to reduce manual toil. Every engineer is expected to work this way and to raise the bar over time. If you're still getting started with AI tooling, this probably isn't the right fit yet. If you have opinions on where it breaks down and you've already changed how you work because of it, the team wants to talk.

About the Role

We’re hiring a Senior Full-stack Engineer to lead and own large parts of the product from ideation to implementation. The role is balanced across frontend (React/TypeScript) and backend (Python/Flask). You will build and iterate on AI-powered creator tools, working alongside AI PMs and ML engineers, and be expected to have a point of view on what AI can and can't do in product. You will build products that get millions of page views per day and scale them toward billions, lead frontend development with delightful UI/UX, and create systems that hold up as the platform grows.

What You’ll Own

1. Build and iterate on AI-powered creator tools alongside AI PMs and ML engineers
2. Build products that get millions of page views per day and scale them toward billions
3. Lead frontend development with delightful UI/UX
4. Create systems and see how all the moving pieces interact
5. Reach for AI tools as your default starting point: scoping, planning, spec-writing, code generation, debugging, and code review

Requirements Must-Have

1. 5+ years of full-stack engineering experience
2. AI-native work style as a hard requirement. AI tools are your default starting point. You can speak concretely about how they've changed your output or pace in the last 6 months.
3. Real production usage of AI coding assistants (Cursor, Copilot, Claude Code, or comparable). Opinions on where they help and where they don't.
4. Comfort using LLMs beyond code generation: planning, spec-writing, debugging, code review
5. Proficient in TypeScript to power frontend React applications
6. Strong Python skills for backend development
7. Familiarity with SQL and Postgres
8. Customer-centric mindset with strong empathy for creators
9. Comfort thriving in ambiguity and scoping solutions with teammates
10. Based in or willing to relocate to SF or NY. Hybrid, Tuesdays to Thursdays in the office.

Nice-to-Have

1. Firebase experience
2. Flask experience
3. Prior experience at small, fast-paced startups
4. Experience with high-scale products (millions of page views per day or comparable)
5. Prior collaboration with AI PMs or ML engineers on AI-powered product features

Hybrid From These Work Locations

1. San Francisco, New York