Senior Backend Engineer - Payroll Platform (Hybrid Zurich)

quitt; Zürich; Hybrid; CHF 140,000 - 170,000; Full time

Job summary

quinn in Zurich is building a country-agn payroll platform. You will own backend modules end to end, from design to production, focusing on quinn ONE across Switzerland, Germany and the UK.

You will work with C#, .NET 10, PostgreSQL, and a modular monolith, ensuring data correctness to the cent, security by design, and observability.

You will mentor teammates in Zurich and our Armenia team, review code, and help shape the API surface and database upgrades.

Qualifications

• Shipped and run production systems in C# and modern .NET / ASP.NET Core.
• Knowledge of PostgreSQL: schema design, transactions, locking, indexing and query optimisation.
• Designed APIs and modules with clear boundaries and dependencies.
• Care for personal and financial data; security is part of design, not afterthought.
• Experience with AI-assisted development and measuring impact.

Responsibilities

• Develop backend modules end to end—from requirements to production.
• Manage the PostgreSQL data model, migrations, transactions and indexing.
• Implement audit trails, logging, and API/versioning strategies.
• Ensure reliability, performance, and security in production systems.
• Define module boundaries and manage dependencies within a modular monolith.
• Mentor and review code with Zurich and Armenia teams.

Skills

C#

.NET / ASP.NET Core

PostgreSQL

API design

Security by design

AI tooling usage

Mentoring

Code review

English communication

Tools

ASP.NET Core

Job description

quinn in Zurich is building a country-agn payroll platform. You will own backend modules end to end, from design to production, focusing on quinn ONE across Switzerland, Germany and the UK.

You will work with C#, .NET 10, PostgreSQL, and a modular monolith, ensuring data correctness to the cent, security by design, and observability.

You will mentor teammates in Zurich and our Armenia team, review code, and help shape the API surface and database upgrades.