Lead Software Developer

Lead Backend Developer

On the lookout for a Lead Backend Developer to join Trainerize powered by ABC Fitness Solutions. ABC Fitness Solutions builds comprehensive, scalable technology and software designed to manage and grow fitness businesses of all sizes. We need a Lead Backend Developer to design APIs and data layers, improve performance and reliability, and grow the backend practice - including code review, standards, and mentoring.

This is a Canada-based individual contributor role. You will lead through technical direction, influence, code quality, mentoring, and cross-functional partnership — not through people management.

If that vision excites you, this is where it gets built. You'll spend your days on the high-volume APIs that power fitness experiences for millions, in an environment where AI agents are part of how you think, build, and review. Every feature you ship and every standard you set helps prove that AI-native engineering isn't a side project here - it's how we build.

Responsibilities:

• Design, develop, test, and document software for existing and new products
• Build, maintain, and optimize.NET backend services (ASP.NET Core, REST APIs) and related data access
• Own and evolve the backend architecture for our products, including RESTful APIs and Microsoft SQL Server (schema, queries, performance)
• Own API strategy: set standards for design, versioning, security, and cross-team contracts, including third-party integration surfaces
• Establish and uphold team practices and guardrails for agentic-IDE development (Cursor or similar), including review standards for agent-generated code
• Partner with frontend (web and mobile), product, and design to define APIs and deliver cohesive, high-quality features
• Work with DevOps on builds, releases, patching, and operational readiness
• Review code, handle merge requests, and help keep code quality, structure, and automation (testing, CI/CD) at a high bar
• Identify bottlenecks, debug production issues, and improve reliability and performance
• Provide technical estimates and communicate progress and risks clearly
• Lead and coach junior and intermediate developers; raise the bar through pairing and feedback
• Improve engineering practices and processes (testing, observability, release discipline) in ways that fit the team
• Share ownership of production health: monitor, respond to critical incidents, and drive fixes for instability or regressions

Qualifications:

• Bachelor's Degree in Computer Science or a related field
• Typically, 7+ years of.NET experience and/or other object-oriented programming languages
• Experience with Microsoft Visual Studio
• Familiar with C#, WebAPIs, MVC, ASP.NET
• Deep RESTful API experience: owning API design, versioning, security, performance, and cross-team contracts at scale
• Habitual use of an agentic coding IDE (Cursor or similar) and a track record of setting review standards for AI-generated code across a team
• In-depth understanding of JavaScript programming and familiar with ES6
• Work effectively in a cloud-based environment; experience with AWS is a strong plus
• Familiar with object-oriented design patterns
• Familiar with RESTful APIs
• Experience with MS SQL Server and T-SQL language
• Understanding of SQL best practices and methodologies and experience investigating and solving SQL performance issues
• Proficient understanding of code versioning tools such as Git and the associated best practices
• Familiarity with Agile methodologies and experience with leading a scrum team

It's Great To Have:

• Prior exposure to fitness/wellness products, multi-tenant SaaS, high-traffic APIs, or cloud-native tooling (containers, observability)
• Experience designing and operating third-party API integrations at scale
• General familiarity with a modern TypeScript / cloud-native SaaS stack is a plus, but not required

Please note that the salary information shown below is a general guideline only and based on employees in Canada and may be different in other countries. Salaries are based upon candidate experience, qualifications, and location, as well as market and business considerations. Our pay range for Canada based candidates for this position is $118,000.00 -- $128,000.00 CAD annually. Your recruiter can share more about the specific salary range for the job location during the hiring process. Also, certain positions are eligible for additional forms of compensation such as bonuses and commissions.

At ABC Fitness, we don't just build technology—we build communities and transform lives. Your work matters here, your growth is supported, and your voice is heard. We welcome diverse talent and encourage you to apply, even if you don't meet every requirement.

ABC'S COMMITMENT TO DIVERSITY, EQUALITY, BELONGING AND INCLUSION:

ABC is an equal opportunity employer committed to diversity, equity, and inclusion. We strive to create a workplace where every employee, client, and partner feels valued, inspired, and empowered to reach their full potential. For us, inclusion isn't just the right thing to do—it's a business imperative. Learn more at abcfitness.com.

About ABC Fitness:

ABC Fitness is the #1 software provider for fitness businesses of any size, all around the world. Supporting 30K clubs, 650K coaches, 40M members, and processing more than $12B in payments every year, ABC Fitness provides scalable, data-driven solutions to simplify club management and engage members and clients.

From personal trainers, boutique studios, and gyms, to international franchise health clubs, ABC Fitness will move your business forward through technology and industry insights. Innovation is at the center of everything we do, across ABC Glofox, ABC Ignite, ABC Trainerize, and ABC Evo. Let's make your fitness vision a seamless reality, together. Learn more at abcfitness.com