Developer Experience Engineer

Black Forest Labs; Paris; A distancia; EUR 140.000 - 190.000; Jornada completa

Descripción de la vacante

Black Forest Labs, the team behind Latent Diffusion and FLUX, is hiring to own the developer experience end-to-end. You’ll shape API, SDKs, dashboards, and onboarding so external developers and agents can build on our platform with speed and confidence.

Work closely with API/platform engineering, research, and DevRel to ship frictionless surfaces, from OpenAPI contracts to Python/TypeScript SDKs, and ensure the MCP server and agent tooling deliver a best-in-class experience.

Formación

• 4+ years building software with developer-facing products.
• Full-stack experience: TypeScript/React/Next on frontend and Python on backend.
• Strong instincts on API design, error handling, and pagination.

Responsabilidades

• Own DevExp as a product surface; ship the next bottleneck.
• Collaborate with platform engineering on API design prior to launch.
• Develop developer-facing dashboard surfaces: playground, API keys, usage, request inspectors, debugging.
• Own MCP server, skills, onboarding paths for agents and the SDK primitives developers rely on.
• Manage entry points: SDKs (Python, TypeScript), MCP server, skills, OpenAPI surfaces.
• Partner with Growth and Product on the developer funnel and DevExp fixes.
• Be opinionated on versioning and change policy, ensuring a smooth developer experience.

Conocimientos

Full-stack development

TypeScript

Python

Go or Rust

API design

SDKs & APIs

Herramientas

OpenAPI

MCP server

Descripción del empleo

We’re the team behind Latent Diffusion, Stable Diffusion, and FLUX—foundational technologies that changed how the world creates images and video. We’re creating the generative models that power how people make images and video—tools used by millions of creators, developers, and businesses worldwide. Our FLUX models are among the most advanced in the world, and we’re just getting started.

Headquartered in Freiburg, Germany with a growing presence in San Francisco, we’re scaling fast while staying true to what makes us different: research excellence, open science, and building technology that expands human creativity.

Why This Role

FLUX is the model developers want. BFL still has to become the platform they choose. In 2026 that platform is judged by a single question, asked by both humans and the agents acting on their behalf: how fast can I go from idea to a production-shaped call, and how good does it feel along the way?

We're hiring one person to own that answer end-to-end. Not the SDK alone, not the dashboard alone, not the API alone — the whole developer experience, for both the humans building on BFL and the agents building on their behalf. You're the person on the team who breathes DevExp: spotting where the platform is friction for a developer or for an agent, deciding whether the fix lives in the API contract, the SDK, the console, the docs surface, the MCP server, or the onboarding flow — and then shipping it.

You sit inside product engineering. You work shoulder-to-shoulder with the API/platform eng team (think: designing the next API revision), with research as new capabilities land, and with DevRel. Your job is to make BFL the platform that wins on developer experience, the way Stripe won payments and Vercel won frontends.

What You’ll Work On

• Own DevExp as a product surface — wherever the bottleneck is, that's where you ship next. One sprint that might be the API contract, the next it's the dashboard onboarding, the next it's an MCP server, the next it's a Python SDK abstraction

• Partner with platform engineering on API design before it ships, not after — bring the developer-and-agent perspective into the room when the contract is being decided

• Work with product engineering on the developer-facing surfaces of the dashboard — playground, API keys, usage, request inspectors, webhook debugging — bringing the DevExp lens to features the rest of the team is already shipping

• Make BFL the best visual AI platform for agents to use. Own the MCP server, skills, agent onboarding paths, and the machine-readable surfaces of the platform. Design the reference patterns and SDK primitives developers reach for when building agentic workflows on FLUX. Stress-test every API and SDK change against "would Claude / GPT / an autonomous agent get this right on the first try?" — and treat agents as a first-class user across the whole product (errors an LLM can recover from, capabilities discoverable without a human reading docs, audit trails that make sense when most of the traffic on an account isn't a person).

• Own the portfolio of entry points developers and agents reach for — SDKs (Python, TypeScript, more on demand), MCP server, skills, OpenAPI / typed surfaces — and treat them as a portfolio, not a hierarchy. SDKs add composable workflows and sane defaults for async / polling / retries; MCP and skills make BFL trivially usable from any agent loop. DevRel and the Creative Technologist team partner on examples, content, and showcase work on top of these surfaces — you own the surfaces themselves.

• Partner with the Growth engineer and Product on the developer funnel — signup → first key → first call → first production call → repeat — and own the DevExp fixes for the cliffs they surface

• Be opinionated. Versioning, error formats, breaking change policy, idempotency, naming — you have takes and you can defend them. The bar is Stripe: an API and SDK so well-designed the docs almost feel unnecessary.

What We’re Looking For

• 4+ years building software, with meaningful time on developer-facing products — SDKs, APIs, dashboards, consoles, platforms developers actually use

• Full-stack comfortable. TypeScript / React / Next on the front, Python (and ideally Go or Rust) on the back. You don't need a separate person to wire the two halves of a feature together.

• Deep instincts on API design — you have opinions about error formats, pagination, async job shapes, breaking changes, and you've lived with the consequences of bad ones

• Fluent in the 2026 agent stack — MCP, tool use, the major agent runtimes — and you know what breaks when an LLM is the one reading your error message or browsing your API

• You've shipped developer-facing product that real external developers depend on. Not internal tooling.

• You ship. This is product engineering, not product management with an IDE open.

Nice to Have

• Background at a developer platform where DevExp was a top-level metric (Stripe, Vercel, Cloudflare, Modal, Replicate, Resend, Linear, Anthropic platform, etc.)

• You've built or meaningfully contributed to an MCP server real users / agents rely on

• Experience with media-generation or other high-latency, async, job-shaped APIs — and the UX puzzles that come with them (polling, webhooks, partial results, cost surprises)

• A public surface — OSS, a writeup, a dashboard you're proud of — that lets us see your taste before the interview

How We Work Together

We’re a distributed team with real offices that people actually use. Depending on your role, you’ll either join us in Freiburg or SF at least 2 days a week (or one full week every other week), or work remotely with a monthly in-person week to stay connected. We’ll cover reasonable travel costs to make this possible. We think in-person time matters, and we’ve structured things to make it accessible to all. We’ll discuss what this will look like for the role during our interview process.

Everything we do is grounded in four values:

• Obsessed. We are a frontier research lab. The science has to be right, the understanding deep, the product beautiful.

• Low Ego. The work speaks. The best idea wins, no matter who said it. Credit is shared. Nobody is above any task.

• Bold. We take the ambitious bet. We ship, we do not wait for conditions to be perfect.

• Kind. People over politics. We treat each other with genuine warmth. Agency without empathy creates chaos.

Base Annual Salary:

EU €140,000 - €190,000 + Equity

Note: Our recruitment process uses AI-assisted tools to help manage and organize applications. All hiring decisions are always made by our team.