Senior Software Engineer - .NET, C# & APIs

Capco; Toronto; On-site; CAD 118,000 - 152,000; Full time

Benefits offered by this job

Health, life, and disability insurance

RRSP or retirement plan with matching

Virtual health care and EFAP

Parental leave top-up

Wellness support and coaching

Job summary

Capco in Toronto is seeking a Senior Software Engineer specializing in C#, .NET, ASP.NET Core, and API development to design, build, and modernize enterprise applications and APIs for clients. The role emphasizes secure, scalable backend services and collaboration across cross-functional teams in an Agile environment.

The ideal candidate has 8+ years of hands-on experience with C#/.NET, RESTful APIs, SQL Server, and modern development practices, including CI/CD, Docker, and AI-assisted tools.

Qualifications

• 8+ years of professional software engineering experience with C#/.NET.
• Strong background in ASP.NET Core, Web API, and RESTful services.
• Experience with SQL Server and data access technologies (EF Core or Dapper).
• Solid understanding of security (OAuth2, JWT) and secure coding.
• Experience with Git, CI/CD, automated testing, and Agile delivery.

Responsibilities

• Design, develop, and maintain scalable backend services and enterprise apps using C#, .NET, ASP.NET Core, and SQL Server.
• Build, enhance, and secure RESTful APIs including authentication, authorization, data validation, and error handling.
• Modernize existing applications, refactor legacy code, and improve performance and reliability.
• Apply secure coding practices and API security standards.
• Participate in design reviews, testing, debugging, and performance optimization.
• Support CI/CD pipelines, containerized deployments with Docker, and modern development workflows.
• Collaborate with engineers, product teams, and QA in an Agile setting; share knowledge and raise engineering standards.

Skills

C#

NET

ASP.NET Core

API development

SQL Server

OAuth2

JWT

CI/CD

Docker

Git

Agile

Backend design

AI-assisted development tools

Tools

Entity Framework Core

Dapper

SQL tooling

Docker

Kubernetes

Job description

Senior Software Engineer - .NET, C# & APIs

The Role

Capco is seeking a Senior Software Engineer with strong expertise in C#, .NET, ASP.NET Core, and API development to join our Technology & Engineering practice in Toronto.

In this role, you will design, develop, modernize, and maintain enterprise applications and APIs that support business-critical solutions for our clients.

We are looking for an experienced, hands-on engineer who brings strong backend development capabilities, an understanding of modern frontend frameworks, and experience delivering secure, scalable, and reliable software.

You will collaborate with cross-functional engineering teams, contribute to technical design decisions, and leverage modern development practices, including AI-assisted engineering tools, to improve software quality and delivery efficiency.

Why This Role Is Open

We are currently hiring for this role due to an existing or newly created vacancy within our organization. This position is open as part of our ongoing business needs, and we are actively reviewing applications to fill this role with a qualified candidate who can make an immediate impact.

What You’ll Do

• Design, develop, and maintain scalable backend services and enterprise applications using C#, .NET, ASP.NET Core, and SQL Server.
• Build, enhance, and integrate secure RESTful APIs, including authentication, authorization, data validation, and error handling.
• Contribute to the modernization of existing applications, including refactoring legacy code, improving performance, and enhancing system reliability.
• Apply secure coding principles and API security practices, including OAuth2, JWT, and common application security standards.
• Participate in technical design discussions, code reviews, automated testing, troubleshooting, and performance optimization.
• Support CI/CD pipelines, containerized deployments, and development workflows using tools such as Docker.
• Collaborate with engineers, product teams, and quality specialists to deliver high-quality solutions in Agile environments.
• Leverage AI-assisted development tools responsibly to support coding, testing, debugging, and documentation while maintaining security and engineering standards.
• Share technical knowledge and contribute to continuous improvements in development practices and software quality.

What We’re Looking For

• 8+ years of professional software engineering experience, with strong hands-on development expertise in C# and .NET.
• Solid experience building and maintaining applications using ASP.NET Core, Web API, and RESTful services.
• Strong understanding of backend architecture, API design, system integrations, and object-oriented programming principles.
• Experience working with SQL Server or comparable relational databases, including data access technologies such as Entity Framework Core or Dapper.
• Understanding of application security principles, including authentication, authorization, OAuth2, JWT, and secure coding practices.
• Experience working with Git, code reviews, automated testing, CI/CD pipelines, and Agile software delivery.
• Strong problem-solving and troubleshooting skills, with the ability to investigate and resolve complex technical issues.
• Ability to collaborate effectively with cross-functional teams and communicate technical concepts clearly.

Bonus Points For

• Experience modernizing legacy .NET applications or migrating enterprise systems to modern architectures.
• Exposure to Azure or AWS cloud environments, Docker, Kubernetes, or cloud deployment troubleshooting.
• Experience with performance optimization, application monitoring, and production support.
• Familiarity with accessibility standards such as WCAG or AODA.
• Experience with Snowflake, data warehouses, or enterprise data integrations.
• Experience with Tailwind CSS, shadcn/ui, or other modern frontend component libraries.
• Experience using AI-assisted software development tools such as GitHub Copilot, ChatGPT, or other AI-powered coding and testing solutions.
• Experience mentoring developers, contributing to technical documentation, or improving engineering standards.

Why Join Capco

• Deliver high-impact technology solutions for Tier 1 financial institutions.
• Work in a collaborative, flat, and entrepreneurial consulting culture.
• Access continuous learning, training, and industry certifications.
• Be part of a team shaping the future of digital financial services.
• Help shape the future of digital transformation across FS & Energy.
• Comprehensive Benefits Coverage – 100% company-paid health, life, and disability insurance effective from Day 1 of employment.
• Retirement Savings Program – Registered Retirement Savings Plan (RRSP) with the option of receiving a matching employer contribution.
• Virtual Health Care and Employee & Family Assistance Program (EFAP) available to employees and their dependents/partners.
• Parental Leave Top-Up, New Parent Gift, and Wellness Support including fitness reimbursement benefits.
• Business Coach from Day 1 with personalized one-on-one coaching to support career growth and professional development.

Inclusion at Capco

We’re committed to making our recruitment process accessible and straightforward for everyone. If you need any adjustments at any stage, just let us know – we’ll be happy to help. We value each person’s unique perspective and contribution. At Capco, we believe that being yourself is your greatest strength. Our #BeYourselfAtWork culture encourages individuality and collaboration – a mindset that shapes how we work with clients and each other every day.

Use of Artificial Intelligence in Talent Acquisition

At Capco, we use artificial intelligence (AI) tools to support and enhance several parts of talent acquisition. This includes using AI-enabled features within LinkedIn to help source potential candidates, speeding up routine recruitment communications such as emails and creating compelling and brand-aligned job postings that accurately reflect role requirements, and AI-scheduling applications to improve the efficiency of interview coordination.

AI is used as a support tool only. All hiring decisions are made by talent acquisition and hiring teams.

#LI-SM1

Pay Transparency

The salary range for this position is listed below. Additionally, this position may also be eligible to receive an annual discretionary/variable bonus payment.

Capco is committed to providing fair and equitable compensation to our people. Our compensation policies and salary ranges are designed to allow our people to progress through the salary range as they demonstrate strong performance and develop in their role over time. The base pay offered to selected candidates will be within the salary range and the placement will vary based upon a variety of factors, including, but not limited to job-related knowledge, skills, experience and internal equity.

$118,000 - $152,000 CAD