AI Fullstack Engineer – Barcelona

About the role

SLNG is looking for an AI Fullstack Engineer to create the front‑end experiences that showcase its real‑time speech AI platform. You will work on the developer portal, demo UIs and real‑time applications, turning complex infrastructure into clean, usable products.

Key responsibilities

• Develop the SLNG developer portal using modern frameworks such as Next.js.
• Build real‑time transcription and text‑to‑speech dashboards.
• Integrate billing, compliance and usage analytics into the UI.
• Design and implement new voice experiences for existing and prospective customers.
• Collaborate with the Developer Relations team to create demo interfaces.

Required profile

• Strong proficiency in React, Next.js and Tailwind CSS.
• Experience building API‑driven, streaming user interfaces.
• Fluent English communication skills.
• Bonus knowledge of WebRTC and WebSockets.

Required skills

• React
• Next.js
• Tailwind CSS
• API integration
• Streaming UX
• WebRTC (optional)
• WebSockets (optional)

What we offer

• Top‑of‑market salary and equity (stock options) for all permanent roles.
• Hybrid work model – 3 days per week in the Barcelona office.
• Flexible benefits: health insurance, gym membership via Cobee.
• Learning & development budget up to €1,000 per year.
• Remote‑work stipend up to €50 per month.
• Equipment package: laptop of choice plus €500 for workstation setup.
• Additional 5 days vacation on top of statutory minimum.