Blaxel

The perpetual sandbox platform

Fullstack Design Engineer

San Francisco
Job type
Full-time
Role
Engineering, Full stack
Experience
Any (new grads ok)
Visa
US citizen/visa only
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Thomas Crochet
Thomas Crochet
Founder

About the role

The role

We're looking for a world-class Founding Design Engineer to own product design end-to-end at Blaxel: from the first exploration to production code running in front of real users. You'll design the experience of a new category of cloud computing, then build it yourself, using AI to ship at a speed that wasn't possible even two years ago.

This is a designer-who-ships role, not a handoff role. We need someone who thinks like a mini design founder, treats the product as their own, and closes the full loop: watch how people use Blaxel, design what should change, implement it in production, measure it, repeat.

What you'll do

Working with the cofounders and leveraging AI as much as possible, you'll own the Blaxel Console product experience from end to end.

  • Design and ship. Take features from concept to polished UI to merged PR. Your designs land in production and get used by real customers, not archived in a Figma graveyard.

  • Use AI as your implementation engine. Pair with AI coding tools to translate your designs into our front-end codebase, accurately and fast, and get them through review like any other engineer.

  • Monitor how humans and AI agents actually use the platform. Watch sessions, dig into usage data, and proactively propose how the UX should evolve. You don't wait for a product owner to hand you a ticket.

  • Close the loop. Ship improvements, measure their impact on activation and platform usage, double down on what works, kill what doesn't.

  • Raise the design craft bar everywhere users touch Blaxel: console, onboarding, docs, emails, marketing site.

  • Build the foundations: design system, component library, and interaction patterns that scale with the product.

Who you are

  • Designer first. Exceptional taste and craft are the bar, and the one thing we won't compromise on. Taste is the rarest skill in this role and the hardest to learn.

  • Obsessive about detail. Spacing, motion, microcopy, empty states, edge cases. You notice the 1px misalignment and it bothers you until it's fixed.

  • Technical enough to own a codebase. Solid front-end fundamentals (TypeScript, React, CSS), and you understand how a production codebase is structured, reviewed, and shipped.

  • Deeply AI fluent. You are extremely curious about AI, and use it as a force multiplier on real design and engineering judgment, not a substitute for it. You're genuinely hungry to push the limit of what one person can ship.

  • Product-minded. You think in user problems and KPIs, not just screens. Comfortable with analytics, session replays, and forming your own hypotheses about what to build next.

  • Mini design founder. Strong ownership, high ambition, and comfort with the pace and ambiguity of an early-stage startup. You'd rather own the outcome than execute a spec.

Why us?

  • Design a new kind of product: Blaxel is used by humans and by AI agents directly. The playbook for designing interfaces that serve both has yet to be written. You'll write it, at the cutting edge of AI infrastructure.

  • Fast growth: We're growing extremely fast, and a substantial proportion of our revenue already comes from AI agents directly using us. We have strong customer love and close to zero churn on the product.

  • Direct impact & autonomy: You'll own the product experience on Blaxel Console end to end, with the full backing of the founders.

  • Tier-1 backing: We're repeat founders & backed by the best in the business (First Round, YC), giving us the resources and network to build a generation-defining company.

About Blaxel

Blaxel is the perpetual sandbox platform for AI agents that need to run code fast. We let you keep infinite, secure code sandboxes on automatic standby while co-hosting your agents for near instant latency. This is enabled by our own technical backbone: a 25ms cold-start serverless compute engine.

Now processing billions of requests, we power the coding agents and background AIs for top AI startups & scaleups like Webflow or HumanBehavior. We solve the agentic infrastructure problems that traditional clouds aren’t built for, such has running AI code securely, statefully and with ultra-low latency — so that AI companies can focus on building generational products.

We raised a $7.3M seed round, led by First Round Capital.

Blaxel
Founded:2024
Batch:P25
Team Size:8
Status:
Active
Location:San Francisco
Founders
Thomas Crochet
Thomas Crochet
Founder
Charles Drappier
Charles Drappier
Founder
Mathis Joffre
Mathis Joffre
Founder
Nicolas Lecomte
Nicolas Lecomte
Founder
Christophe Ploujoux
Christophe Ploujoux
Founder
Paul Sinaï
Paul Sinaï
CEO & Co-Founder