Senior Software Engineer

Ersilia; San Francisco (CA); Hybrid; USD 180,000 - 250,000; Full time

Job summary

Ersilia is seeking a Senior Full-stack Engineer to own major product areas from ideation to implementation. You will work across frontend (React/TypeScript) and backend (Python/Flask) to build AI-powered creator tools with input from AI PMs and ML engineers.

You will shape scalable systems, ship features powering millions of page views, and collaborate in a hybrid setup with in-office Tuesdays to Thursdays in SF or NY.

Qualifications

• 5+ years of full-stack engineering experience.
• AI-native work style is mandatory; AI tools are your default starting point.
• Real production usage of AI coding assistants (Cursor, Copilot, Claude Code, or comparable).
• Comfort using LLMs beyond code generation: planning, spec-writing, debugging, code review.
• Proficient in TypeScript for frontend React applications.
• Strong Python skills for backend development.
• Familiarity with SQL and PostgreSQL.
• Customer-centric mindset with strong empathy for creators.
• Based in or willing to relocate to SF or NY. Hybrid, Tue–Thu in office.

Responsibilities

• Build AI-powered creator tools alongside AI PMs and ML engineers.
• Lead frontend development with delightful UI/UX.
• Scale products to millions of page views per day and toward billions.
• Scope, plan, spec write, code, review using AI tools.
• Create systems and coordinate moving parts across the platform.

Tools

Cursor

Copilot

Claude Code

Flask

Firebase

PostgreSQL

SQL

TypeScript

Python

AI coding assistants

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