Senior Backend Engineer (Platform and API)

About Buffer

At Buffer, we make social media and brand building software for small businesses, creators, and individuals. Our mission is to provide essential tools to help small businesses get off the ground and grow. Through exceptional customer service and uplifting content, we help our customers believe they can succeed and do good along the way.

We’re a fully distributed team, and we’ve always aimed to do things a little differently at Buffer. Since the early days, we’ve had a focus on building one of the most unique and fulfilling workplaces by rethinking a lot of traditional practices. We also default to transparency, so you can read all about our metrics, and our successes and failures along the way on our Transparency Dashboard.

We hire and work from all over the world. Please note that we do travel to work together in-person once or twice per year, and those events are highly encouraged to build deeper connections among our small team.

We're united by Buffer's values, and we celebrate our unique differences. We strive to create a diverse and inclusive work environment and are building a culture where underrepresented groups are welcome, and can flourish.

About the role

We’re looking for a senior backend engineer to join the Channels and Platform team at Buffer. You will play a key role in building our public API and creating a future plug-in ecosystem that would elevate Buffer into a platform other developers can build on top of, providing creators the next generation of tools for writing, editing, and managing content.

We’re looking for someone with first-hand experience designing, implementing, and maintaining public APIs and/or extensibility platforms, who enjoys going deep — designing data models, shaping APIs, improving performance, and helping our systems scale with clarity and confidence. You’ll work closely with product, design, and mobile + web engineers to bring ideas to life and keep the user experience smooth and resilient.

We work iteratively and in tight feedback loops, balancing thoughtful engineering with steady momentum. In addition to building a new platform, you’ll help us strengthen our internal systems, making them faster, more scalable, and better equipped to power content creation at scale. There’s real room here to shape this direction and make an impact.

What you’ll do

• Be part of a small, dedicated squad within the Channels and Platform team responsible for Public API development.

• Lead the development of the backend systems for the Buffer Platform. This includes creating an API for core Buffer features, internal services to ensure Public API stability, availability, high performance, and developer tools for platform clients.

• Improve and evolve our internal systems — helping consolidate services into a monorepo, improve tooling and observability, and reduce complexity across the board.

• Collaborate closely with engineers, product, and design to scope work, explore trade-offs, and find the simplest path to something great.

• Make steady improvements to performance, reliability, and data modeling, helping us scale quality over time.

• Participate in on-call rotation (all engineers take on a 24/7 week-long shift once a quarter on average) and day-to-day maintenance work required to keep the lights on the systems owned by the team (this includes bug fixing, addressing security vulnerabilities, incident follow-ups, etc.)

• Contribute to shaping our engineering culture by sharing knowledge, reviewing code, and leading by example.

Helpful skills and experience

• You have practical experience designing, implementing, and maintaining public APIs, plug-in ecosystems, or extensibility platforms.

• You have deep experience with modern stack — we use Node.js, TypeScript, GraphQL, and MongoDB.

• You’ve led backend projects from start to finish — shaping architecture, guiding trade-offs, and delivering reliable systems that support real-world product needs.

• You have strong systems thinking. You look beyond the immediate task, anticipate downstream effects, and help teams converge on architecture that supports the long game.

• You’ve worked across teams to drive platform or infrastructure improvements — whether simplifying service boundaries, improving observability, or evolving internal tooling.

• You’ve contributed to collaborative or multi-user product features, and you understand the data, consistency, and UX considerations that come with them.

• You’re fluent with modern AI tools — not just using them for code generation, but integrating them into how you debug, document, explore ideas, and reduce manual effort.

• You care about performance, scale, and clean abstractions — and know how to measure, prioritize, and improve them pragmatically.

• You’ve influenced engineering culture through code reviews, mentoring, or leading by example, and you’re comfortable being a resource for others on architectural decisions.

• You have a personal stake in the world of content creation; maybe you’ve run a newsletter, built an audience on social media, or regularly shared your own work online. You’ve used Buffer before and care about the experience of planning, creating, and publishing content.

• You thrive in remote, async environments. You’re clear in your thinking, generous with context, and don’t wait for perfect information to get started.

• You’ve likely been doing this for 7+ years, but experience depth and impact matter more to us than a specific number.

Our tech stack

• We use NodeJS, TypeScript, and MongoDB, but part of our core legacy systems are written in PHP (including old APIs)

• We are in the process of migrating to GraphQL, and we use Apollo Client in our web application.

• We are running our services on AWS with Kubernetes. We follow a microservices architecture and are currently moving our services into a central shared monorepo.

• On the frontend, we use React and TypeScript for our web frontends

• We have an internal design system called Popcorn that we started developing last year. It is built with Radix primitives, CSS modules, Storybook, and our own system of design tokens

• We write automated tests with jest, react testing library (for integration tests), and Playwright (for e2e tests)

Interview process

Here's what our hiring process for this role is like.

1. Application. When submitting your application and resume, tell us why you want to join Buffer and take your time. This is your chance to make a strong first impression.

2. Hiring manager interview. Chat with the hiring manager for your role to understand what it takes to work at Buffer. This is an opportunity for both sides to get to know each other and determine whether our expectations align. Good candidates prepare questions, use our product, and clearly articulate what they look for in their role.

3. Async assignment. 30-minute asynchronous assignment to help us understand how you'd collaborate with the team.

4. Technical interviews. 1-2 interviews focused on system design, technical leadership, and engineering craft. No whiteboarding, live coding, or trick questions. This gives you a chance to meet a few engineers from Buffer.

5. Collaboration period. Work with us on a real project for about 10 hours (we'll pay you for your time). Expect async Slack communication, Zoom meetings, pairing sessions, and heads-down coding. You'll also meet more team members, including product managers and designers.

6. Final interview. You will have the opportunity to meet with Joel Gascoigne, our CEO. This is a great chance for you to gain a deeper understanding of Buffer's strategy, values, and work processes.

7. Offer. We wrap it up with an offer and discuss the final details. We would align on the last bits before we make you part of the Buffer team 💛

At Buffer, we value diversity of experience, and we understand that comes in many forms. We’re dedicated to adding new perspectives to the team. So, if your experience is close to what we’re looking for, please consider applying.

By submitting the application, you consent to Buffer collecting and processing your personal data for recruiting purposes.