Software Engineer | Rust | Advertising Technology SaaS

round8 talent search; France; Remote; EUR 59,000 - 72,000; Full time

Job summary

round8 talent search is seeking a Software Engineer to join a fast-growing Advertising Tech SaaS company focused on Rust-backed services and high-throughput APIs. The role is remote with Paris time zone, CDI contract, and a €65,000.00 yearly salary.

The team designs, builds and operates backend services with end-to-end ownership, including architecture, testing, deployment and observability. Strong experience with typed languages and APIs is required.

Qualifications

• 5+ years backend software engineering experience, with production API ownership.
• Experience designing and operating APIs in production.
• Fluency in English; French fluency is mandatory.

Responsibilities

• Design, build and operate backend services and APIs at significant scale.
• Own architecture, development, testing, deployment and observability of services.
• Collaborate via pair programming and PR reviews, challenging requirements when needed.

Skills

Backend engineering

Rust

APIs

OpenAPI/gRPC

SQL

ClickHouse

Kubernetes

CI/CD

Observability

Production ownership

Terraform

OpenRTB

Prebid

Tools

ClickHouse

BigQuery

Snowflake

Druid

Kubernetes

Terraform

GitHub Actions

Job description

Software Engineer | Rust | Advertising Technology SaaS

Remote | Paris Time Zone | CDI contract | €65,000.00 per year

We’re working with a fast-growing B2B SaaS / AdTech business that builds high-performance technology used by some of Europe’s leading digital publishers and media companies. They’re now looking to hire a Software Engineer to join their experienced engineering team and help scale a platform already processing several billion requests every day.

PLEASE NOTE

Fluency in French is mandatory for this role

This is a great opportunity for a backend engineer who enjoys high-throughput, real-time systems, APIs and genuine end-to-end ownership. You don’t need to be a Rust expert already (though Rust experience would be preferred) – strong experience with another typed or systems language such as Go, C++, Kotlin or Scala, combined with the motivation to learn Rust, is still very relevant.

The role

You’ll join a small, highly experienced engineering team working closely with Product to design, build and operate backend services and APIs at significant scale.

You’ll have genuine ownership of what you build – from architecture and development through to testing, deployment, observability and production. The team works collaboratively through pair programming and PR reviews, and engineers are encouraged to challenge requirements rather than simply execute tickets.

What we’re looking for

We’re looking for 5+ years of backend software engineering experience, and you will have previously designed and operated an API in production.

We’d particularly like to speak with engineers who have experience across:

• REST, OpenAPI and/or gRPC APIs, including authentication, versioning, quotas and documentation


• Rust, or production experience with a typed/systems language such as Go, C++, Kotlin or Scala


• SQL and large-scale analytical data platforms such as ClickHouse, BigQuery, Snowflake or Druid


• Cloud infrastructure, containers and Kubernetes


• CI/CD and production observability


• Owning services in production, including incidents, monitoring and on-call responsibilities.


• Experience with AdTech/programmatic, OpenRTB, Prebid, MCP/LLM integrations, TypeScript or Terraform would be a bonus, but isn't essential. Tech environment

The core backend is Rust, with ClickHouse for data. Infrastructure spans AWS and OVH managed Kubernetes, alongside Cloudflare, Terraform and Argo Rollouts. The engineering environment also includes GitHub Actions and Datadog, while the team has strongly adopted AI-assisted development using Claude and Claude Code.

The engineering culture

This isn\'t an environment for engineers who simply want a backlog of tightly defined tickets. The team values people who are comfortable with ambiguity, taking ownership, challenging product decisions constructively and that care about the commercial impact of what they\'re building.

The engineering team is around 10 experienced engineers, with technical decisions owned collaboratively by the team. It\'s fully remote and aligned to Paris working hours, with the team getting together in person for two days every three months.