Forward Deployed Engineer - ML (London)

Modal Labs; Greater London; On-site; GBP 70,000 - 120,000; Full time

Job summary

Modal in London is seeking Forward Deployed ML Engineers who work at the intersection of deep technical work and direct customer impact. As an ML FDE, you’ll partner with leading AI teams to optimize production workloads, including LLM serving and model training.

You’ll join a team of engineers and researchers who build, demo, and instrument real-world AI systems, collaborating with product and sales to deliver customer value while advancing Modal’s platform.

Qualifications

• 2+ years of professional ML engineering experience.
• Experience with inference optimization, model training, GPU programming, or ML infrastructure.
• Familiar with serving and training toolchains (e.g., vLLM, SGLang); depth in at least one.
• Strong communicator capable of technical architecture discussions with engineers and leadership.
• Interested in working directly with customers; energized to understand problems and help solve them.
• Willing to work in person in London.

Responsibilities

• Architect and optimize production AI workloads with customer use cases.
• Collaborate with product and sales teams, contributing as an engineer and product stakeholder.
• Build trusted relationships with technical leaders at client companies.
• Conduct technical demos, experiments, and proofs of concept to demonstrate Modal’s advantages.
• Contribute to open‑source projects and publish technical content showcasing Modal’s capabilities.

Skills

ML engineering

Inference optimization

GPU programming

ML infrastructure

Customer-facing

Tools

vLLM

SGLang

Job description

About Us:
AI needs a new infrastructure layer. We're building it at Modal.

Every era of computing brought new workloads that previous infrastructure couldn't support: mainframes, databases, and the cloud. Each time, the company that rebuilt the layer underneath defined the decade. AI is no different, except it touches everything instead of one slice, and the window to build the layer underneath it is open right now.

Our customers include category-defining companies like Ramp, Cognition, DoorDash, and Suno. They rely on Modal for instant GPU access, sub-second container starts, and native storage, so it's simple to serve low-latency inference, fine-tune models, and access production-ready sandboxes at scale.

We've passed $1B in annualized run rate, up 15x from a year ago. In October 2026 we raised a $750M Series D led by Accel at a $15.75B valuation.

Our team includes creators of popular open‑source projects (e.g.,Seaborn,Luigi), academic researchers, international olympiad medalists, and experienced engineering and product leaders with decades of experience.

The Role:

We’re looking for Forward Deployed ML Engineers who want to work at the intersection of deep technical work and direct customer impact. As an ML FDE, you’ll partner with leading AI companies and foundation model labs to help them achieve state‑of-the‑art performance on their most demanding workloads: LLM serving, model training (SFT, RLHF), audio pipelines, scientific computing, and more. You’ll help teams reach outcomes most engineers can’t on their own.

The FDE team today includes world‑class software engineers, computational scientists, ML engineers, and former founders. We’re looking for people with strong engineering fundamentals, deep curiosity across the AI stack, and energy for working directly with customers on hard problems.

What You’ll Work On:

• Work hands‑on with companies like Suno, Cognition, and Meta to architect and optimize production AI workloads on Modal


• Contribute to open‑source projects (members of the team are active contributors to SGLang) and publish technical content that demonstrates Modal’s capabilities across the AI stack


• Collaborate with Modal’s product and sales teams, contributing to the platform as both an engineer and a product stakeholder


• Build trusted relationships with technical leaders (CTOs, VPs of Engineering, ML leads) at companies doing frontier AI work


• Conduct technical demos, experiments, and proofs of concept that make Modal’s performance advantages tangible

You May Be a Fit If:

• You have 2+ years of professional ML engineering experience, ideally with hands‑on work in inference optimization, model training, GPU programming, or ML infrastructure


• You’re familiar with the serving (e.g., vLLM, SGLang) and training (e.g., slime, verl, TRL) toolchains and can go deep on at least one (you don’t need all of them)


• You’re a strong communicator who can go deep on technical architecture with an engineering team and clearly articulate tradeoffs to technical leadership


• You have a genuine interest in working directly with customers: you find it energizing to understand someone else’s problem and help them solve it


• You’re willing to work in person in London

Nice‑to‑Have:

• Side projects, open‑source contributions, or published work you’re proud of in ML or systems performance