Staff Software Engineer, Voices

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.

Benefits

• This is a remote role from an EU country, UK or Switzerland.
• Salary starts at EUR/GBP/CHF 130,000 base + stock option plan.
• Full‑time employment only - contractors not accepted.
• 25 days of leave + local holidays (no extra paid or unpaid leave).
• Visa sponsorship only if you are already in the UK/EU and need support.