Senior Backend Engineer - AI Stream

Join nesto - proudly named Canadian Rocketship 2025. A Deloitte Fast 50 company evolving alongside Canada’s top tech innovators and disrupting a 2.1 Trillion-dollar mortgage industry at light speed by building the mortgage ecosystem of the future.

BUILD lending technology with the best developers, AI engineers, and mortgage experts in the country. Work on a modern tech stack and a development framework designed to unlock your full potential and accelerate your career.

Why join us

Hypergrowth: Deloitte Fast 50 - 3 years in a row

Tech community credibility: TechTO Canadian Rocketship 2025

Industry leadership: CLA Lending Company of the Year - 4 consecutive years

Talent magnet: CMP Top Mortgage Employer 2025

Trusted technology: powering major financial institutions across Canada

An entrepreneurial culture built on trust, speed, uncomfortable ambition, being stronger together, and a relentless obsession with our clients.

Who are you

Builders. Problem-solvers. Curious minds. People who move fast, embrace innovation, and believe we’re stronger together.

If you trust your skills and want to build real technology that reshapes an entire industry, join us now.

About nesto and Nesto Cloud

nesto is Canada’s leading provider of mortgage technology and financing solutions, managing $73B+ CAD in residential and commercial mortgages, with 1,000+ team members across 12 offices nationwide. You will be working on Nesto Cloud, Canada’s most advanced cloud platform. At the heart of this platform is Maestro, an AI-powered ecosystem that makes mortgage professionals dramatically more productive across sales, underwriting, and loan servicing.

As Senior Backend Engineer you will be responsible for owning the development of high-impact technical features and subsystems within our AI agent platform. You will be responsible for mentoring junior engineers through code reviews and collaborative problem-solving, helping them grow into successful, independent contributors.

About the team

Several major tech projects are progressing in parallel at a high delivery pace. Structured by squads, the tech teams are working on different products and nesto experiences based on strong algorithms and AI to meet business objectives. Our technology allows customers to shop and access mortgage products by enabling them to complete their mortgage applications and transactions digitally.

You'll be joining the AI Stream, working on Maestro - nesto's document validation platform for mortgage underwriting. This platform combines deterministic, rules-based validation with AI-powered document classification and matching (using models like Gemini, Claude, and OpenAI), so you'll work daily at the boundary between conventional backend systems and AI-assisted processing.

What you’ll be doing

Make sound technical trade-offs within that domain, communicating them clearly to your team lead

Contribute to code reviews and give useful feedback to peers

Collaborate with cross-functional team members to hit delivery timelines without compromising quality

Troubleshoot, debug, and improve performance/reliability within your area

Lean on senior engineers for guidance on novel or ambiguous architectural problems

Grow your understanding of how nesto's deterministic rules engine and AI perception/matching layers work together (Vertex AI-based classification, embedding-based name/address matching)

Who you are:

Bachelor's degree in Computer Science or related field (or equivalent experience)

3–5 years of experience as a software developer, with backend web development experience

Strong experience in backend programming, ideally with Python, FastAPI or a comparable web framework

Familiarity with relational databases (ex. MySQL)

Solid understanding of software engineering fundamentals: testing, design patterns, agile development process

Good interpersonal and communication skills, comfortable working with engineers senior to them

Genuine interest in AI/ML-adjacent backend work - no ML expertise required, but curiosity about how deterministic and AI-based systems interact

Exposure to LLM/embedding APIs (Vertex AI, OpenAI, or similar) is a plus

Track record of independently owning a feature or subsystem

The Reward

The A-Team: Work alongside high-performing talent in the industry.

Accelerated Growth: The slope of your learning curve here will be vertical. You will touch more production systems in one year than you would in five years at a bank.

Top-Tier Coverage: Premium benefits plan fully paid by nesto, including comprehensive insurance and unlimited access to telemedicine and mental health services for you and your family.

Rest & Recharge: 4 weeks of vacation to ensure you stay at peak performance.

Best-in-Class Tools: Access to the resources and tech you need to execute without friction.

Working framework: the environment that makes you productive and enables teamwork.

Diversity & Inclusion

At nesto, we believe that creativity and collaboration are the result of a diverse team. We are committed to fostering a culture of diversity, equity, inclusion, and belonging, and we strongly encourage women, people of colour, LGBTQIA+ individuals, and individuals with disabilities to apply. We are committed to creating a workplace that is inclusive and welcoming to all.

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