Sr. Back-end Developer (.NET)

TL;DR

Sr. Back-end Developer (.NET): Building and scaling the core financial engine and platform infrastructure for a leading accounting SaaS with an accent on performance optimization and system-technical excellence. Focus on refactoring critical applications, implementing robust APIs, and mentoring junior developers to ensure system reliability under heavy load.

Location: Hybrid in Rotterdam, Netherlands

Company

hirify.global is an international IT scale-up providing a business-critical SaaS solution for accounting and financial administration, backed by the Visma Group.

What you will do

• Scale and optimize the core financial engine and platform infrastructure to handle heavy system loads.
• Refactor existing codebases to improve overall performance, readability, and maintainability.
• Develop new features, APIs, and system integrations with external parties and Visma solutions.
• Implement high-performance code following industry best practices and software craftsmanship.
• Mentor and coach junior developers through peer reviews and technical guidance.
• Collaborate with cross-functional teams and stakeholders within an Agile/Scrum environment.

Requirements

• At least 4 years of experience as a back-end developer using .NET technologies (C# or VB.NET).
• Strong proficiency with relational database engines, specifically MSSQL.
• Experience in API development utilizing HTTP, REST, and .NET Web API.
• Proven track record of coaching and mentoring junior team members.
• Hands-on experience with Azure DevOps, GitHub, and Agile methodologies.
• Must be based in or able to work in a hybrid setup in Rotterdam, Netherlands.

Nice to have

• Familiarity with AWS services such as S3, SNS, and SQS.
• Experience with JavaScript frameworks like Vue, Angular, or Prototype.
• Knowledge of OCR systems and Machine Learning (ML).
• Experience with NoSQL databases (e.g., MongoDB, DynamoDB).
• Experience with ASP.NET.

Culture & Benefits

• Generous training budget for certifications and professional courses.
• 28 vacation days with the option to purchase 5 additional days.
• Workation benefit allowing up to 5 weeks of remote work per year.
• Competitive base salary with full pension coverage.
• Home-office budget and high-quality hardware provided.
• Wellness perks including lifestyle coaches and healthy lunches.

Hiring process

• Initial application and screening by the Talent Acquisition Team.
• Technical test to showcase coding and architectural skills.
• Technical deep-dive interview with a Cloud Engineer.
• Cultural and management fit interview with People & Culture and Software Development managers.