Senior Fullstack Engineer

About Scalar:

Building on a great API is one of the best feelings in software — every interface you want is right there, and it all just works. Building on a bad one is the opposite: out-of-date docs, no SDK in your language, no MCP server. We started Scalar to fix that.

We're a small team (around ten engineers and designers) who wear a lot of hats and obsess over our craft. We think every company deserves Stripe-level docs, SDKs, and MCP servers from day zero — not just the ones with a platform team to build them. Open-source is in our DNA: our whole team contributes to and maintains repositories across the API ecosystem, including the standards everyone relies on, like OpenAPI.

We keep things lean and move without layers of process — engineers pick up problems, talk to each other, and ship. We're looking for owners with high agency: people who see what needs doing and do it. If you do your best work with a lot of autonomy and very little ego, you'll feel at home here.

The role

You'll work across the entire product surface — Docs, SDKs, the API Client, and Agent Scalar (our MCP servers) — shipping features from the API all the way to a polished UI. This is a high-ownership role for someone who likes to take something from an idea to production and out the door, then keep making it better.

As a senior engineer, you'll also raise the bar for the people around you — through code review, design discussions, and good defaults — without becoming anyone's manager.

What you'll work on

• A modern TypeScript stack, end-to-end

• Docs — the documentation platform: Markdown/MDX, OpenAPI and AsyncAPI references, two-way Git sync, and AI/MCP chat, owned from backend to UI

• SDK generation — turning a customer's OpenAPI document into type-safe client libraries across TypeScript, Rust, Python, Go, PHP, Java, and Ruby.

• The API Client — our open-source, offline-first Postman alternative, built on open standards and shipping across macOS, Windows, and Linux

• Agent Scalar — secure MCP servers and AI features for chatting with APIs, built on the Vercel AI SDK, the MCP SDK, and Vertex AI

You might be a fit if

• You're a strong generalist who has shipped real product end to end, and you've operated at a senior level on a TypeScript-heavy stack

• You can take broad ownership of a feature — from conception to production deployment — and move between areas as the work demands

• You're comfortable in a modern frontend framework and happy working in Vue 3 (or ramping into it quickly)

• You make decisions and communicate them clearly without waiting to be told what to do

• You care about craft and developer experience, and you'd rather collaborate to the right answer than win the argument

• You operate with a high level of kindness and clear communication

Nice to have

• Experience building developer tools, or working with OpenAPI and JSON Schema

• Vue 3 / Vite depth, and a feel for server- and static-rendered front ends

• Experience with real-time or collaborative editing (CRDTs, Yjs, or similar)

• Experience shipping AI/LLM or MCP-powered product features

• An in-house-first instinct — we build our own tooling and work hard to reduce external dependencies

Where we work

Remote. Most of the team overlaps with US time zones (PT–ET), and we prefer candidates in the US or Western Canada for that overlap. If you're a strong fit in a European time zone and can make the overlap work, apply anyway and say so.

We're fully remote and offer flexible, unlimited time off. We believe prioritizing the team's well-being makes the work better and more meaningful.

Other Notes:

• While the role will involve a significant portion of backend service management, the candidate will also be expected to contribute to the frontend and may be asked to lead the development of new features in either space.

• We are a small team of 10 developers and wear many hats. We expect everyone to pitch in and help out where needed.

• We are open to both fixed-term contract and full-time permanent positions. Compensation Range: $150-250k (CAD)/$105-180 (USD) based on experience