Machine Learning Engineer / ML Engineer - Roleplay Sessions

Synthesia; Greater London; Hybrid; GBP 110,000 - 140,000; Full time

Benefits offered by this job

RSUs

25 days leave

Job summary

Synthesia, the world’s leading AI video platform, seeks an experienced ML-focused software engineer to build the coaching engine for roleplay scenarios. You will design models that listen to learners, score performance, and generate real-time feedback within a product‑oriented team.

This applied ML role requires strong software development skills, pragmatism, and a bias toward fast iteration to deliver tangible product outcomes.

Qualifications

• Must have seven years of software engineering experience, with at least two years at senior level.
• Experience in high‑performing teams operating at scale with strong engineering culture.
• Strong alignment with commercial success and product focus.

Responsibilities

• Build the ML engine that coaches role‑play sessions in real time.
• Score performance, generate feedback, and drive AI avatar responses based on learner input.
• Collaborate across products to ship practical ML features and improvements.

Skills

ML application into products

Software engineer experience

Senior level experience

Commercial focus

Bias toward action

Job description

Synthesia is the world’s leading AI video platform for business, used by over 90% of the Fortune 100. Founded in 2017, the company is headquartered in London, with offices and teams across Europe and the US.

As AI continues to shape the way we live and work, Synthesia develops products to enhance visual communication and enterprise skill development, helping people work better and stay at the center of successful organizations.

Following our recent Series E funding round, where we raised $200 million, our valuation stands at $4 billion. Our total funding exceeds $530 million from premier investors including Accel, NVentures (Nvidia's VC arm), Kleiner Perkins, GV, and Evantic Capital, alongside the founders and operators of Stripe, Datadog, Miro, and Webflow.

About the role

Synthesia Roleplay Sessions is a training tool that lets people practice real conversations with AI avatars. Instead of just watching training videos, learners do interactive roleplay exercises, like practicing a sales pitch or handling a customer complaint with an AI coach. The AI gives instant feedback so people know what they did well and what to improve.

Managers can use a dashboard to track which employees have completed their training, see how well they performed, and measure if the training actually improved their skills. The whole platform is built around learning by doing rather than just passive video watching.

For your ML engineer role, you'd be building the AI engine that makes the coaching work. That means creating the models that listen to what learners say during roleplay, score their performance, generate helpful feedback in real time, and decide how the AI avatar should respond next based on what the learner does.

This is an applied ML position, not a research one. We expect you to have a good understanding of ML but on the other side to be a good product-focused software developer as you will be expected to work on different products.

Please bring with you:

• Ability to apply your machine learning knowledge to solve real product problems.

• At least seven (7) years of experience as a software engineer, with at least 2 years at senior level.

• Experience in a high-performing engineering team operating at scale, whether in a scale-up or established organisation recognised for strong engineering culture.

• Strong alignment with commercial success.

• Pragmatism and bias towards action. This role requires comfort with fast iteration.

Why join us?

We’re living the golden age of AI. The next decade will yield the next iconic companies, and we dare to say we have what it takes to become one. Here’s why,

Our culture

At Synthesia we’re passionate about building, not talking, planning or politicising. We strive to hire the smartest, kindest and most unrelenting people and let them do their best work without distractions. Our work principles serve as our charter for how we make decisions, give feedback and structure our work to empower everyone to go as fast as possible.You can find out more about these principles here.

Serving 50,000+ customers (and 50% of the Fortune 500)

We’re trusted by leading brands such as Heineken, Zoom, Xerox, McDonald’s and more. Read stories from happy customers and what 1,200+ people say on G2.

Proprietary AI technology

Since 2017, we’ve been pioneering advancements in Generative AI. Our AI technology is built in-house, by a team of world‑class AI researchers and engineers. Learn more about our AI Research Lab and the team behind.

AI Safety, Ethics and Security

AI safety, ethics, and security are fundamental to our mission. While the full scope of Artificial Intelligence's impact on our society is still unfolding, our position is clear:People first. Always. Learn more about our commitments to AI Ethics, Safety & Security.

The hiring process:

1. Tech Recruiter Interview (30-40min) - Technical background, previous experience, and what you're looking for

2. Delivery and Impact Interview (60min) - Deep dive into your past projects, impact, and ways of working

3. Technical Rounds:

   • Work Scenario Round (BE Focus) (75-90min) - Hands‑on problem solving (not Leetcode style); collaboration exercise with one of our engineers. AI‑assisted coding welcome.

   • System Design Technical Discussion (60min) - Real architectural problems we've faced in production

   • Leadership Retrospective (60min) - Examples of collaboration and growth; your future manager or VP of Engineering will outline your role and what's ahead

4. Final debrief on our side which leads to an offer or the end of the process.

You can find more details on what to expect and how to prepare HERE. The process does not need to take long - we can be done in two weeks time.

Other important info:

• Our preference is for this role to based either in-office or remote in the following locations: UK, Germany, Switzerland or Ireland.
  We may also be able to support remote workers in other locations across Europe subject to compliance and right to work checks.

• The salary starts at EUR/GBP/CHF 120.000 base + RSU's.

• This is full-time employment only -no contractors possible - through our entities or EOR (OysterHR).

• Everyone at Synthesia gets 25 days of leave + local holidays.