Staff Engineer

Sonio

Staff Engineer at Sonio enhancing prenatal screening and diagnosis using AI technology. Leading technical decisions and driving engineering velocity within a hybrid role.

Posted 4/30/2026full-timeParis • 🇫🇷 FranceLead💰 €85,000 - €100,000 per yearWebsite

Tech Stack

Tools & technologies

CloudDistributed SystemsElixirPostgresReactTypeScript

About the role

Key responsibilities & impact

Architect high-scale, resilient systems and arbitrate complex technical decisions to ensure the platform remains performant as we grow
Be the in-house Elixir / Phoenix expert squads rely on for the deepest problems
Drive architecture for scale: concurrency, fault tolerance, clustering, back-pressure, recovery patterns
Own the hardest problems end-to-end—from scoping and design to implementation—while distributing knowledge across the team
Author RFCs / ADRs for cross-squad changes and review others' designs
Drive the refactors and tech-debt reductions that unlock velocity
Grow the team through pairing, code reviews, design reviews and internal talks
Contribute to senior / staff hiring (case design, tech deep-dives)

Requirements

What you’ll need

8+ years of software engineering, with 3+ years in Elixir in production at scale (real bottlenecks debugged)
You have expertise in web & cloud native environment
Deep BEAM mastery: GenServers, Phoenix, Ecto / PostgreSQL performance
Distributed systems in a cloud context: fault tolerance, clustering, consistency/availability trade-offs, back-pressure, and recovery
Strong architecture and API design; comfortable with event-driven, data-intensive systems
Written communication is strong enough to author RFCs / ADRs that others use as a reference
Technical leadership without authority: drives consensus across squads, mentors peers
Fluent English; French a plus
Bonus: experience in a regulated environment (medical devices, fintech…), React / TypeScript familiarity

Benefits

Comp & perks

10% bonus 📊 Check your resume score for this job Improve your chances of getting an interview by checking your resume score before you apply. Check Resume Score

ATS Keywords

✓ Tailor your resume

Applicant Tracking System Keywords

Tip: use these terms in your resume and cover letter to boost ATS matches.

Hard Skills & Tools

ElixirPhoenixBEAMGenServersEctoPostgreSQLdistributed systemsAPI designevent-driven systemsdata-intensive systems

Soft Skills

technical leadershipmentoringwritten communicationconsensus buildingknowledge distribution