Senior Software Developer, C#/.NET, React

Calliere Group

. Take ownership of complex features from early design through production support .

Posted 11/3/2026full-timeCanadaSeniorWebsite

Core Competencies

Role fit

Core Competencies

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Demonstrates expertise in building and supporting complex production systems with a strong focus on C#, .NET, React, and TypeScript. Capable of leading technical design, mentoring developers, and promoting best practices in security, testing, and documentation.

Highest-signal resume keywords

C# ProgrammingASP.NET DevelopmentReact DevelopmentSQL Server ExperienceTechnical Mentorship

ATS Keywords

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Applicant Tracking System Keywords

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Hard Skills

C#ASP.NETRESTful APIsReactTypeScriptJavaScriptSQL ServerAutomated TestingCI/CDTechnical Design

Soft Skills

Problem-SolvingCollaborationTechnical JudgmentMentoringCommunication

Tools & Technologies

AzureCloud PlatformsVersion Control SystemsCI/CD ToolsTesting Frameworks

Industry Keywords

PaymentsFintechSecurity-Sensitive FieldProduction SystemsTechnical Documentation

Tech Stack

Tools & technologies

AzureCloudJavaScriptReactSQLTypeScript.NET

About the role

Key responsibilities & impact

Take ownership of complex features from early design through production support
Turn loosely defined problems into clear, well-scoped technical work
Write clean, secure, maintainable and well-tested front-end and back-end code
Identify risks, dependencies and blockers early
Investigate production issues independently and fix root causes
Lead feature-level technical design covering APIs, data models and integrations
Evaluate trade-offs and recommend practical solutions
Consult the Technical Lead and architecture group on wider system decisions
Promote security, testing, observability, performance and documentation practices
Simplify and automate repetitive work
Build accessible, semantic and standards-compliant front-end experiences with usability and SEO considered
Conduct thorough code reviews
Mentor developers and help them become more independent
Share knowledge through documentation, pairing, demos and workshops
Influence solutions to recurring technical problems
Improve team processes and delivery practices
Collaborate with the Technical Lead, Product, QA and DevOps

Requirements

What you’ll need

Around 6 or more years building and supporting complex production systems
Strong C# and .NET skills, including RESTful APIs and back-end services
Solid working knowledge of React and TypeScript/JavaScript
Experience with relational databases such as SQL Server
History of troubleshooting production problems independently and leading design decisions
Good technical judgment and comfort working through ambiguity
Azure or another major cloud platform (nice to have)
Automated testing and modern CI/CD (nice to have)
Background in payments, fintech or another security-sensitive field (nice to have)
Experience mentoring developers or building a strong code review culture (nice to have)

Benefits

Comp & perks

Remote work arrangement
Occasional in-person team days in the Greater Toronto Area
Full-time, permanent employment
Inclusive workplace
Collaborative, flexible culture