Senior Back-End 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.

As you get to know Buffer and consider joining the journey, feel free to read more from Kirsti, who recently documented her first 30 days at Buffer, as well as from Hailley, who captured why she still calls Buffer home after 8 years.

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.

• 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 API for core Buffer features, internal services to ensure Public API stability, availability and 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.

• You have a practical experience designing, implementing, and maintaining public APIs, plug-in ecosystem 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 share 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.

• 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, we use Apollo Client in our web application

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

• On the front-end, we use React and TypeScript for our web front-ends

• 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)

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.

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