Senior Fullstack Engineer

About Circleback Circleback is building the source of truth for everything said at a company–starting with best-in-class AI meeting notes, action items, and search. Every company runs on conversations — meetings, calls, emails — but almost none of that context is usable after the fact. We’re building the platform that captures, organizes, and acts on all of it, so teams can actually use what they know. We're a small team backed by Y Combinator. Profitable, growing virally, and thousands of paying customers including PostHog, Browserbase, Gumloop, and more.

Why join

• We ship fast with a high bar for quality.

• Small team, large problem: the category we're building didn't exist a few years ago.

• Profitable and growing virally through word of mouth, not paid acquisition.

• Build software people actually love and use every day.

• Free lunch and dinners, competitive salary and equity.

• Flexible health coverage and 401K matching.

The Role This is a senior individual contributor role for someone who can take a genuinely ambiguous problem, figure out what the team should build, and carry it through to production. You’ll work across the product and stack, make technical decisions that shape how we build beyond a single feature, and help raise the bar for the rest of the engineering team. We’re looking for someone who can see how the pieces fit together, make good calls without a lot of structure, and still stay close to the code.

What you'll do

• You’ll build across the product: web with React, Next.js, Prisma, and SWR; desktop with Electron and Swift; and mobile with React Native.

• Take on ambiguous problems, figure out the right approach, and ship them across the full stack.

• Set technical direction, not just execute it.

• Work on AI-powered workflows, search, transcription, automations, and performance.

• Raise the engineering bar through code review, mentorship, and shared tooling.

• Experiment with the latest AI models and help decide what's worth building.

• Work directly with the founders. No layers or handoffs.

You might be a good fit if

• You have 3-5+ years of experience shipping production software and owning real outcomes.

• You have strong product judgment and enjoy making decisions, not just implementing them.

• You think about systems, leverage, and long-term engineering quality.

• You're low ego, direct, and comfortable operating without much process.

• You're excited by how AI is changing both products and software engineering.

People who've done well here have often been former founders, early startup engineers, or engineers who've owned major systems end-to-end.

Interview process

• Intro conversation (30 min)

• Technical interview (1 hour)

• Product-focused technical interview (1 hour)

• Paid two-day work trial in San Francisco