Senior Software Engineer .NET C#

Product Pulse; Warszawa; Hybrid; PLN 180,000 - 260,000; Full time

Benefits offered by this job

Hybrid work policy

Rydoo On Tour mobility

Flexible work environment

Training & coaching

Team events

Permanent contract

Onboarding programme

Job summary

Rydoo, the leading expense management platform, is seeking a Software Engineer in our G6 squad to design and build backend systems that power expense processing for thousands of users worldwide. You will work in a cross-functional, autonomous team focused on delivering fast, scalable solutions.

The role offers a hybrid work policy with the Warsaw hub, opportunities to explore AI-powered features, and a path to impact through modern cloud technologies.

Qualifications

• Several years of experience with backend development.
• Excellent knowledge of .NET and C#.
• Experience with ORM (Entity Framework or NHibernate) and SQL Server.
• Team player in a cross-functional, agile environment.
• Experience with cloud (Azure/AWS/GCP) and DevOps is a plus.
• Experience with LLMs is a plus.

Responsibilities

• Design and build backend systems that power the expense management platform.
• Collaborate in a cross-functional, autonomous squad to improve time-saving features.
• Explore AI-powered features and optimize performance for growing user base.
• Maintain clean, tested code and ensure scalability.

Skills

Backend development

C#

.NET

Entity Framework

SQL Server

REST APIs

Azure / AWS / GCP

Agile

DevOps

LLMs

Angular

Education

CS degree

Tools

Service Bus

NHibernate

Angular

Job description

About Rydoo & Semine

At Rydoo, we make expense management simple, so people can focus on the important work, not their receipts. More than one million users trust us to submit, approve, and control expenses faster and smarter.

Semine shares that same mission. Since 2015, the team has been building AI technology that removes the repetitive, time‑consuming parts of accounting, helping finance teams work smarter.

In July 2025, Semine joined forces with Rydoo to shape the future of financial automation. Together, we’re creating a complete, AI‑powered platform that simplifies accounts payable and expense management, helping businesses run simpler, faster, and smarter financial operations.

We’re a global team of over 200 people who believe great tech should make life easier. If you have big ideas and want to build something that actually helps people, you’ll fit right in.

Rydoo Snapshot

• Ambitious international team
• 33 nationalities speaking over 15 languages
• 6 hubs across 3 continents
• Easy‑to‑use spend management app available on iPhone and Android
• Supporting over 10,000 clients and 1 million users worldwide
• 4.6 employer score on Glassdoor
• Hybrid work policy

The Role

At Rydoo, we build smart, simple solutions that help people spend less time on expenses and more on what matters. As a Software Engineer in our G6 squad, you’ll shape the core of our product — designing backend systems that make expense management faster and smarter for thousands of users worldwide.

You’ll work in a cross‑functional, autonomous team focused on saving time for our end users. From improving pre‑filling and automating hotel itemisation to exploring AI‑powered features, your work will directly influence how companies experience automation every day.

AI is reshaping expectations, and G6 is leading that charge. This mission is just the starting point — as the squad grows, you’ll refine it together to maximise alignment, innovation, and impact.

Requirements

• Several years of experience with backend development.
• Excellent knowledge of .NET and C#.
• Good knowledge of Entity Framework (or any ORM like NHibernate) and SQL Server or similar.
• Team player with a passion for writing clean and testable code within a cross‑functional team.
• Experience optimizing the performance and scalability of applications to support an ever‑growing user base.
• Experience with Service‑Oriented Architecture using Service Bus is a plus.
• Knowledge of Azure Cloud (or AWS, GCP) is a plus.
• Agile and DevOps experience is a plus.
• Experience with LLMs is a plus.
• Ability to stay up‑to‑date with industry trends, best practices, and emerging technologies to continuously improve development processes and drive innovation.
• Optional: Full‑Stack experience, e.g., Angular, is a plus but not required.
• Preferable: A degree in computer science or a related field, but equivalent experience is equally valuable.

Benefits

• A competitive package, including salary and benefits
• €1000/year learning and development budget
• Rydoo Hybrid Work Policy: flexibility to work from home while also fostering team collaboration in our Warsaw hub once a week.
• Rydoo On Tour: an international mobility program that allows employees to temporarily relocate to a Rydoo office.
• Professional freedom and a flexible work environment
• Upskilling through training and coaching programs
• Regular company and team events
• Wonderful international team with more than 33 different nationalities
• Spectacular onboarding programme for all new Rydooers
• Permanent contract

Why Join Us

At Rydoo / Semine, we celebrate diversity and are committed to creating an inclusive environment for all employees. We value and encourage ongoing learning opportunities and career progression.

Even if you don't tick every box but see yourself contributing, we encourage you to apply. We’re more interested in finding a well‑rounded individual with a can‑do attitude. Your passion, dedication and desire to learn are what matter most to us.