Senior Software Engineer - QuantumBlack, AI by McKinsey

United States Digital Space LLC; Toronto; On-site; CAD 120,000 - 180,000; Full time

Job summary

QuantumBlack in Toronto is seeking an experienced software engineering leader to own architectural decisions and set the technical direction for AI-enabled, production-grade systems. You will mentor and collaborate with clients and internal teams to deliver scalable software across the full stack.

You will drive design decisions across cloud, CI/CD, and API layers, working with designers, product managers, and industry experts to create lasting value for clients and accelerate AI adoption.

Qualifications

• Undergraduate or master’s degree; or equivalent experience.
• 5+ years of experience developing full‑stack applications, writing code that is readable, testable, maintainable, and scalable.
• Deep proficiency in at least two frontend or backend frameworks, with the ability to independently evaluate and select packages, define data structures, and deliver robust, scalable solutions across the full stack; hands‑on experience with languages and frameworks including JavaScript/TypeScript, React, Angular, Next.js, Vue.js, Java, Spring, C#, or Node.js; SQL and NoSQL databases; cloud platforms (AWS, Azure, or GCP); and CI/CD tooling (Jenkins, Docker, CircleCI, or similar)
• Demonstrated ability to design complex, secure APIs — including REST and GraphQL — with a focus on scalability and maintainability, implementing advanced features such as rate limiting, caching, and API gateways, grounded in expert knowledge of software design patterns including microservices and distributed architectures
• Proficiency across two cloud providers with the ability to build complex IaC and CI/CD pipelines from scratch, implement zero downtime deployment strategies, and apply cloud‑native architecture concepts to ensure scalability, reliability, and elasticity
• Advanced proficiency in AI‑assisted engineering, orchestrating specialized agents across parallel workstreams, building reusable agent tooling, and exercising sound technical judgment on AI safety and application boundaries
• Experience architecting AI systems and ensuring engineering quality, utilizing robust LLM evaluation frameworks, guardrails, and validation methodologies to deliver reliable, production‑grade AI applications
• A security‑first mindset, able to advocate for standards and compliance, implement authentication flows such as OAuth and OIDC, proactively identify and mitigate security issues during development, and mentor others in secure development practices; ensures quality through comprehensive testing strategies and performance optimization
• Experience leading collaborative, cross‑functional engineering teams and fostering a strong engineering culture
• Exceptional time management to meet your responsibilities in a complex and largely autonomous work environment
• Strong communication skills, both verbal and written, in English and local office language(s), with the ability to adjust your style to suit different perspectives and seniority levels
• Please review the additional requirements regarding essential job functions of McKinsey colleagues.Our unwavering commitment to integrity drives everything we do, guiding us to always act in the best interests of our clients, our people, and the communities we serve.

Responsibilities

• Own architectural decisions and set the technical direction for your workstream.
• Mentor client and internal teams, helping engineers grow their craft and adopt engineering practices.
• Collaborate with designers, product managers, and industry experts to deliver software solutions.
• Design robust systems and make architectural judgments on AI-enabled software.
• Partner with clients from technical teams to C-level executives to drive business value.

Skills

Full-stack development

JavaScript/TypeScript

Frontend frameworks

Backend languages

REST/GraphQL APIs

Cloud platforms

CI/CD tooling

AI-enabled systems

Security practices

Leadership

Education

Bachelor's or Master’s degree

Tools

Jenkins

Docker

CircleCI

Job description

Job ID: 111024Toronto

Do you want to do work that matters, alongside supportive leaders who will help you grow faster than you ever thought possible? Are you a creative problem-solver who is energized by challenges? You’ve come to the right place.

YOUR IMPACT

You will bring deep technical expertise and engineering leadership to some of the most complex and high-impact challenges facing clients across industries.

You will own architectural decisions, set the technical direction for your workstream, and ensure the team delivers scalable, production-ready solutions that create lasting value.

You will work hands-on across the full stack, designing robust systems and making technical judgments — on architecture, framework selection, cloud design, and the thoughtful application of AI — that shape what your team builds and how they build it. You will mentor both client and internal teams, helping engineers at all levels grow their craft and adopt the engineering practices that make great software possible. Your technical leadership will be felt not just in the code you write, but in the standards, you set and the people you develop along the way.

Your work will help solve some of the most complex and high-impact challenges facing clients across industries. Collaborating across QuantumBlack, AI by McKinsey and QuantumBlack Labs teams, you will help develop innovative software capabilities and scalable enterprise solutions. You will help build robust technical foundations for production-ready, AI-enabled systems. Your contributions will directly support the firm's ability to accelerate AI adoption, solve complex business problems at scale, and enable clients to achieve meaningful, lasting impact.

Working in cross-functional teams, you'll collaborate closely with designers, product managers, and industry experts to deliver software solutions. By partnering with clients from technical teams to C-level executives, you'll help solve complex problems that drive tangible business value and continue to grow your skills as a client-facing technologist.

Your work offers a unique opportunity to grow at the forefront of AI and software engineering. You'll develop expertise at the intersection of technology and business by tackling diverse challenges in the evolving AI landscape. Working alongside multidisciplinary teams, you'll gain a holistic understanding of how software engineering enables advanced AI while collaborating with some of the leading technologists and AI experts in the industry.

YOUR GROWTH

Driving lasting impact and building long-term capabilities with our clients is not easy work. You are the kind of person who thrives in a high performance/high reward culture - doing hard things, picking yourself up when you stumble, and having the resilience to try another way forward.

In return for your drive, determination, and curiosity, we'll provide the resources, mentorship, and opportunities you need to become a stronger leader faster than you ever thought possible. Your colleagues—at all levels—will invest deeply in your development, just as much as they invest in delivering exceptional results for clients. Every day, you'll receive apprenticeship, coaching, and exposure that will accelerate your growth in ways you won’t find anywhere else.

When you join us, you will have:

• Continuous learning: Our learning and apprenticeship culture, backed by structured programs, is all about helping you grow while creating an environment where feedback is clear, actionable, and focused on your development. The real magic happens when you take the input from others to heart and embrace the fast-paced learning experience, owning your journey.
• A voice that matters: From day one, we value your ideas and contributions. You’ll make a tangible impact by offering innovative ideas and practical solutions, all while upholding our unwavering commitment to ethics and integrity. We not only encourage diverse perspectives, but they are critical in driving us toward the best possible outcomes.
• Global community: With colleagues across 65+ countries and over 100 different nationalities, our firm’s diversity fuels creativity and helps us come up with the best solutions for our clients. Plus, you’ll have the opportunity to learn from exceptional colleagues with diverse backgrounds and experiences.
• World‑class benefits: On top of a competitive salary (based on your location, experience, and skills), we provide a comprehensive benefits package to enable holistic well‑being for you and your family.

YOUR QUALIFICATIONS AND SKILLS

Undergraduate or master’s degree; or equivalent experience

5+ years of experience developing full‑stack applications, writing code that is readable, testable, maintainable, and scalable

Deep proficiency in at least two frontend or backend frameworks, with the ability to independently evaluate and select packages, define data structures, and deliver robust, scalable solutions across the full stack; hands‑on experience with languages and frameworks including JavaScript/TypeScript, React, Angular, Next.js, Vue.js, Java, Spring, C#, or Node.js; SQL and NoSQL databases; cloud platforms (AWS, Azure, or GCP); and CI/CD tooling (Jenkins, Docker, CircleCI, or similar)

Demonstrated ability to design complex, secure APIs — including REST and GraphQL — with a focus on scalability and maintainability, implementing advanced features such as rate limiting, caching, and API gateways, grounded in expert knowledge of software design patterns including microservices and distributed architectures

Proficiency across two cloud providers with the ability to build complex IaC and CI/CD pipelines from scratch, implement zero downtime deployment strategies, and apply cloud‑native architecture concepts to ensure scalability, reliability, and elasticity

Advanced proficiency in AI‑assisted engineering, orchestrating specialized agents across parallel workstreams, building reusable agent tooling, and exercising sound technical judgment on AI safety and application boundaries

Experience architecting AI systems and ensuring engineering quality, utilizing robust LLM evaluation frameworks, guardrails, and validation methodologies to deliver reliable, production‑grade AI applications

A security‑first mindset, able to advocate for standards and compliance, implement authentication flows such as OAuth and OIDC, proactively identify and mitigate security issues during development, and mentor others in secure development practices; ensures quality through comprehensive testing strategies and performance optimization

Experience leading collaborative, cross‑functional engineering teams and fostering a strong engineering culture

Exceptional time management to meet your responsibilities in a complex and largely autonomous work environment

Strong communication skills, both verbal and written, in English and local office language(s), with the ability to adjust your style to suit different perspectives and seniority levels

Please review the additional requirements regarding essential job functions of McKinsey colleagues.Our unwavering commitment to integrity drives everything we do, guiding us to always act in the best interests of our clients, our people, and the communities we serve.