AI / Fullstack Engineer
You will build frontends for developer portals and real-time voice applications. The role offers equity, flexible benefits, and a learning budget.
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88,000+ live jobsHybrid in Barcelona·Full-time·Added over a year ago
This job was published a year ago
Full-time hours
Per the ad.
Hybrid
Office and home days — the ad has the split.
Have the right to work in Spain
SLNG doesn't mention sponsorship in the ad.
Work in English
English is required, per the ad.
Be near Barcelona for hybrid days
No relocation package mentioned.
We pay top of the market → We want serious talent in the team, and we benchmark compensation accordingly.
Equity → All full-time, permanent roles include stock options - we want everyone to share in the upside as we build.
Flexible benefits: Health insurance, gym, and more via Cobee.
L&D: Annual budget (up to €1000) for training, courses, or conferences.
Remote work support: Monthly stipend (up to €50) to cover wifi or other costs.
Great equipment: Laptop of your choice plus €500 to set up your workstation in year one, with top-ups in the following years.
Time off: Additional +5 days vacation on top of the statutory minimum
About The Role → You'll make speech models fast.
Strong background in ASR/TTS.
PyTorch/ONNX experience.
Familiar with GPU profiling and optimisation.
Fluency in English.
SLNG is building the backbone for real-time speech AI, enabling developers to run voice applications anywhere in the world with local compliance and ultra-low latency.
Our founding team comes from the core of AI and developer tooling in the USA, with experience scaling platforms trusted by the world's best builders. Meet Luke, Founder & CEO, and Ismael, Founder & CPO at SLNG.
We're bringing the San Francisco mindset to Europe with our first hub in Barcelona, and we have the support of leading international VCs and Angel investors who are backing the SLNG journey.
Challenge → Today, most speech infrastructure is US-centric, unreliable, and difficult to deploy globally. SLNG is changing that by delivering a platform that is:
Local: deployed close to users and compliant with regional regulations
Fast: designed for real-time voice experiences
Open: built to integrate with the tools and workflows developers already use.
From real-time transcription to voice AI applications, SLNG is creating the Voice AI gateway that will empower the next generation of speech-powered products.
As Speech Model Performance Engineer, you'll work closely with Ismael and the founding tech team to shape the technical foundation of SLNG. From TTS voices to multilingual ASR, you'll benchmark, optimise, and productionize speech inference at scale.
Quantise neural TTS and STT models to run with minimal latency on heterogeneous GPU hardware.
Benchmark ASR models across dialectal variations, measuring Word Error Rate (WER) and latency trade-offs.
Implement continuous batching and KV-cache reuse for streaming inference.
Profile GPU utilisation with CUDA kernels to identify bottlenecks in large-scale inference.
Hybrid by design → 3 days/week in the Barcelona office for collaboration and culture.
Intro call with one of the founders
Case Study
Panel conversation with members of the SLNG Team
Final discussions
Job offer
SLNG is an early-stage artificial intelligence company building infrastructure for real-time voice agents. Its platform sits between a customer's orchestrator and their speech models, providing routing, noise cancellation, transcription and text-to-speech optimization with claimed reductions of 53% in LLM cost and 39% in latency. The company promotes UNMUTE//, an open standard for describing voice agents as code, and runs compute across 15 sovereign regions with 30+ models served through one API. It holds ISO 27001 and SOC 2 Type II certifications and states HIPAA and GDPR compliance.
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