Senior Software Engineer

100; United States; On-site; USD 140,000 - 190,000; Full time

Job summary

100, a PropTech platform, seeks a senior full-stack engineer who cares about what we build and why. You will own features across the stack, from frontend to API and database, and ship with speed and quality.

You thrive in a fast-moving startup, value pragmatic design, and collaborate with a small, senior team to move fast while keeping code solid. Fluency with AI-assisted development and a bias to action are essential, as you’ll shape architecture, improve performance, and push the stack forward

Qualifications

• 7+ years of professional software engineering experience.
• Strong TypeScript, Node.js, and React experience.
• Experience across the stack with Hono, Next.js, and React Router.
• Python experience with FastAPI and Django.
• Solid SQL knowledge, preferably PostgreSQL, and experience with Supabase.
• Hands-on fluency with AI coding tools in production.
• Proactive problem solver with low ego and bias to ship.

Responsibilities

• Ship full-stack features across our TypeScript and Python services.
• Own significant parts of the product end-to-end — frontend, API, database.
• Design the technical approach for individual features — data model, API shape, system fit.
• Use AI tools as a core part of how you build — code, debugging, docs, speed.
• Improve the platform: performance, reliability, developer experience.
• Help shape architecture decisions at the stack level.
• Make the call and ship an 80% solution today and iterate.
• Collaborate with a small, senior team to ensure quality for trusted applicants.

Skills

TypeScript

Node.js

React

AI tools usage

Code reviews

Performance optimization

Security-minded

DevOps familiarity

Tools

Hono

Next.js

React Router

FastAPI

Django

Supabase

PostgreSQL

Terraform

Kubernetes

Ansible

Linux

Job description

100 is a PropTech platform disrupting multifamily's rental process. 100 sets a new standard through cutting-edge verification and fraud prevention tools that eliminate bias, fraud, and friction. Built and backed by industry experts who know the challenges firsthand.

About this role

We're a seed-stage startup, which means what you bring matters more than at a bigger company. We move fast, ship often, and expect everyone to own outcomes, not just tickets.

We are looking for a senior full-stack engineer who is product-minded — you care about what we're building and why, not just how it's built, and you can tell the difference between a problem worth solving well and one worth solving fast. You ship, learn, and iterate rather than waiting for the "right" solution. You genuinely like solving problems — you notice things, a flaky test, a confusing error message, a slow query, and you fix them without waiting to be asked. You don't need a ticket to tell you something's broken. And you do it without ego: you ask questions instead of assuming, take feedback easily, give credit freely, and are just as happy fixing a small papercut as leading a big design decision.

You'll also need to be genuinely fluent with AI-assisted development — using tools like Claude Code or Cursor to move faster without sacrificing code quality, and knowing where AI helps and where it doesn't. When you find something that works — a better prompt pattern, a new tool, a smarter workflow — you share it, so the whole team levels up together. We are pragmatic about technology. We adopt new tools when they earn it and keep what works. You will have meaningful input into where the stack goes next.

What you will do

• Ship full-stack features across our TypeScript and Python services
• Own significant parts of the product end-to-end — frontend, API, database — and jump in wherever the problem is, whether or not it's "yours"
• Design the technical approach for individual features — data model, API shape, how it fits into the system it touches
• Use AI tools as a core part of how you build — for code, debugging, docs, and speed
• Improve the platform: performance, reliability, developer experience
• Help shape architecture decisions at the stack level — the tools, patterns, and infrastructure choices that affect the whole team, not just one feature
• Make the call and act — ship an 80% solution today over a perfect one next week, and iterate from there
• Collaborate closely with a small, senior team on a product where engineering quality directly affects whether properties trust us with their applicants

What you'll bring

• 7+ years of professional software engineering experience
• Strong TypeScript, Node.js, and React experience, with comfort working across the stack using tools like Hono, Next.js, and React Router
• Python — we have production services in FastAPI and Django alongside our TypeScript stack, so you should be comfortable building and maintaining Python backends, not just scripting
• Solid SQL, ideally Postgres, and experience with Supabase
• Real, hands‑on fluency with AI coding tools — not just curiosity, but daily use in production
• A track record of being the person who solves the problem in front of them, regardless of whether it's technically in scope
• Comfort with ambiguity and a fast‑moving, small‑team pace — priorities shift, and you adjust without needing a lot of hand‑holding
• Bias to action — you'd rather ship, learn, and adjust than deliberate for too long
• Low ego — you ask for help early instead of spinning, take feedback well, and give credit generously
• You share what you know — in code reviews, docs, or just answering questions — because a stronger team makes better products
• A deep, first‑principles understanding of web performance — caching, rendering, network waterfalls, why a page actually feels fast or slow
• Security‑minded — you think about auth, data handling, and attack surface as part of the job, not an afterthought
• You've dabbled in DevOps — Terraform, Kubernetes, Ansible, comfortable on Linux
• Experience building agentic systems — multi‑step, tool‑using AI workflows, not just calling a model for a single response