At a Glance
- Tasks: Build and operate backend systems for AI voice generation, ensuring high-quality outputs.
- Company: Join Synthesia, the leading AI video platform trusted by top brands worldwide.
- Benefits: Competitive salary, stock options, 25 days leave, and a remote work environment.
- Other info: Dynamic, fast-paced culture focused on building and collaboration.
- Why this job: Be part of an innovative team shaping the future of AI and visual communication.
- Qualifications: Experience in backend development, preferably with Python/FastAPI and third-party APIs.
The predicted salary is between 130000 - 130000 £ per year.
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.
About the role
You will work on the core systems powering Synthesia’s script preview and voice generation experience, ensuring users can reliably generate high-quality voiceovers across a wide range of languages, providers, and use cases. You will build and operate backend services that orchestrate multiple text-to-speech (TTS) providers, alongside Synthesia’s in-house models, delivering a seamless and consistent experience to end users despite underlying system complexity.
You will be responsible for designing and evolving systems that handle provider reliability, request routing, and output consistency, ensuring users can generate and regenerate voice content with predictable, high-quality results. You will contribute to user-facing product problems from a backend perspective, working closely with frontend engineers to ensure APIs and workflows integrate cleanly into the product experience.
You will own projects that span multiple systems and domains, such as:
- Building robustness layers (retries, throttling, failover) to handle unreliable third-party providers
- Designing persistence systems to ensure consistent voice outputs across generations
- Improving how voice data is stored, retrieved, and reused
You will also work on newer initiatives around voice discovery and recommendations, helping users find the best voices by building evaluation systems, improving recommendation logic, and adding observability to monitor quality. You will evaluate your work through system performance and user experience metrics, using observability to debug and continuously improve reliability. You will collaborate closely with product, frontend, and R&D teams, ensuring backend systems support both current product needs and future innovation.
What we’re looking for
- You have several years of experience building and operating backend systems in production.
- You’re a strong backend engineer (we use Python/FastAPI) with experience designing reliable, observable services, ideally working with third-party APIs or distributed systems.
- You have a product mindset and focus on solving user-facing problems, not just backend architecture.
- You’re comfortable working close to the client, understanding how APIs are consumed and how backend decisions impact the end-user experience.
- You’re willing to step outside your comfort zone — including jumping into frontend code when needed to debug and understand end-to-end flows.
- You work well in an iterative, experiment-driven environment, shipping quickly and improving based on data and feedback.
- Experience with observability tools (e.g. Datadog), workflow systems (e.g. Temporal), or evaluation/recommendation systems is a plus, but not required.
- Comfortable with touching the frontend in any language and/or framework.
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.
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.
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.
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.
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.
The hiring process:
- 30-40min call with our Technical Recruiter
- 45min call with an Engineering Manager about your past projects
- 90min Live Coding interview, a collaboration exercise with our Engineer (not Leetcode style)
- 60min System Design, technical discussion usually about a real problem we had in production
- 45min call with leadership, focus on examples of collaboration, growth and going through details of your future team
The process does not need to take long - we can be done in seven working days.
Other important info:
- This is a remote role from an EU country, UK or Switzerland.
- The salary starts at EUR/GBP/CHF 130,000 base + stock option plan.
- This is full-time employment only - no contractors possible - usually through OysterHR.
- Everyone at Synthesia gets 25 days of leave + local holidays (no extra paid or unpaid leave possible).
- We only sponsor VISA if you are in the UK/EU country already and need support.
Staff Backend Engineer, Voices employer: Synthesia
At Synthesia, we pride ourselves on fostering a dynamic and innovative work culture that empowers our employees to excel in their roles. As a leading AI video platform headquartered in London, we offer competitive salaries, generous leave policies, and a collaborative environment where your contributions directly impact the future of visual communication. Join us to be part of a pioneering team that values creativity, growth, and ethical AI development.
StudySmarter Expert Advice🤫
We think this is how you could land Staff Backend Engineer, Voices
✨Tip Number 1
Get to know the company inside out! Research Synthesia's products, values, and recent news. This will help you tailor your conversations and show that you're genuinely interested in being part of the team.
✨Tip Number 2
Practice makes perfect! Prepare for the live coding interview by working on similar problems and collaborating with peers. This will boost your confidence and help you showcase your skills effectively.
✨Tip Number 3
Don’t shy away from asking questions during interviews! It shows your curiosity and willingness to learn. Plus, it gives you a chance to understand how you can contribute to the team.
✨Tip Number 4
Apply through our website! It’s the best way to ensure your application gets noticed. Plus, you’ll find all the details about the role and the hiring process right there.
We think you need these skills to ace Staff Backend Engineer, Voices
Some tips for your application 🫡
Tailor Your Application:Make sure to customise your CV and cover letter for the Staff Backend Engineer role. Highlight your experience with backend systems, especially in Python/FastAPI, and how you've tackled user-facing problems in the past.
Showcase Your Projects:Include specific examples of projects you've worked on that demonstrate your skills in building reliable services and working with third-party APIs. We love seeing how you've contributed to real-world solutions!
Be Clear and Concise:When writing your application, keep it straightforward. Use clear language to explain your experience and how it aligns with our needs. We appreciate brevity but also want to see your personality shine through!
Apply Through Our Website:Don’t forget to submit your application through our website! It’s the best way for us to receive your details and ensures you’re considered for the role. We can’t wait to hear from you!
How to prepare for a job interview at Synthesia
✨Know Your Tech Stack
Make sure you’re well-versed in Python and FastAPI, as these are key to the role. Brush up on your experience with backend systems and be ready to discuss how you've designed reliable services in the past.
✨Understand User Impact
This role is all about user-facing problems, so think about how your backend decisions affect the end-user experience. Prepare examples of how you've solved user issues through backend solutions in previous projects.
✨Be Ready for Collaboration
You’ll need to work closely with frontend engineers, so be prepared to discuss how you’ve collaborated across teams before. Highlight any experiences where you jumped into frontend code to debug or improve workflows.
✨Show Your Problem-Solving Skills
Expect to tackle real-world problems during the interview. Think of specific challenges you've faced in production and how you approached them. Be ready to demonstrate your iterative, experiment-driven mindset.
