Software Engineer 3

mongodb· AI Builder Experience
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About this role

The Agent Research and Tooling team, part of MongoDB's AI Builder Experience organization, owns the platform layer around agents: how teams author, distribute, evaluate, monitor, and improve agent skills and agent behavior. We are hiring a software engineer to build and maintain the tooling, evaluation systems, and quality gates behind MongoDB's agent skills.

This is a software engineering role at the intersection of developer tooling, applied AI, and software quality. You will take loosely defined agent and tooling problems, break them into workable plans, and ship durable internal systems: command-line tools, reusable libraries, evaluation harnesses, and CI workflows.

This role is open to remote work in Canada or can be based out of any of our Canada offices.

What you'll do

  • Build and maintain agent skills and the infrastructure to validate, evaluate, publish, and maintain them
  • Design evaluation datasets and workflows that compare agent behavior against a baseline and produce actionable quality signals
  • Build agent metrics and observability: skill selection and routing, success and failure outcomes, tool calls, latency, and token usage
  • Design safety and quality gates for agent-authored content: rule packs, static analysis, confidence thresholds, structured verdicts, and bounded suppression
  • Create CLIs, libraries, and MCP integrations that other repositories adopt and that run in local development and CI
  • Integrate tooling into GitHub Actions and other CI workflows, including secrets, annotations, exit codes, and artifacts
  • Build code-generation quality checks, such as anti-pattern catalogs and linting for AI-generated MongoDB code
  • Investigate real failures such as nondeterministic results, false positives, and unsafe generated guidance, and turn them into reusable improvements
  • Collaborate with engineers, security partners, and product teams; communicate trade-offs, risks, and ownership across teams

Examples of the problems you'll solve

  • How can tests verify an agent tool's structured result when item order may vary, but counts, required fields, and values must remain correct
  • How can a CI gate flag unsafe instructions in an agent skill without treating every neutral mention as an incident or letting cautionary wording hide a real instruction
  • How can an evaluation suite show whether a skill improves answers over a baseline and give authors enough signal to improve it

What we're looking for

  • 2+ years of experience building production software, developer tools, internal platforms, or automation systems
  • Software engineering fundamentals in API design, testing, error handling, and maintainability
  • Experience building CLIs, libraries, test infrastructure, static analysis, or CI/CD workflows
  • Ability to design systems that are usable by developers and reliable in automation
  • Experience reasoning about correctness and safety with ambiguous input, nondeterministic output, false positives, or untrusted content
  • Comfort in an evolving R&D environment where the right abstraction emerges through prototypes and feedback
  • Written and verbal communication, including explaining technical trade-offs and aligning stakeholders across teams

Nice to have

  • Experience with agentic systems, LLM applications, prompt or rubric-based evaluation, or AI-assisted development
  • Experience building eval harnesses, benchmark datasets, quality metrics, LLM-as-judge workflows, or human-review tooling
  • Experience with Go, Python, JavaScript/TypeScript, Java, or C#
  • Experience with GitHub Actions security, secret handling, static rule engines, or policy enforcement
  • Experience moving prototypes into production

What success looks like

In your first year, you will:

  • Ship tooling that makes agent skills or developer workflows easier to test, review, and adopt
  • Improve the quality and interpretability of evaluations, not just their count
  • Convert recurring manual work and fragile scripts into documented, reusable automation
  • Make security, correctness, and operational trade-offs explicit in the designs you ship
  • Earn adoption from partner teams through clear interfaces and reliable CI
  • Own projects independently while collaborating on shared systems

About MongoDB

MongoDB is built for change, empowering our customers and our people to innovate at the speed of the market. We have redefined the data platform for the AI era, enabling builders to create, transform, and disrupt industries with software. MongoDB’s unified data platform, the most widely available, globally distributed data platform on the market, helps organizations modernize legacy workloads, embrace innovation, and unleash AI. Our cloud-native platform, MongoDB Atlas, is the only globally distributed, multi-cloud data platform and is available across AWS, Google Cloud, and Microsoft Azure.

With offices worldwide and over 67,000 customers, including 75% of the Fortune 100 and AI-native startups, relying on MongoDB for their most important applications, we’re powering the next era of software.

Our compass at MongoDB is our Leadership Commitment, guiding how and why we make decisions, show up for each other, and win. It’s what makes us MongoDB. 

To drive the personal growth and business impact of our employees, we’re committed to developing a supportive and enriching culture for everyone. From employee affinity groups, to fertility assistance and a generous parental leave policy, we value our employees’ wellbeing and want to support them along every step of their professional and personal journeys. Learn more about what it’s like to work at MongoDB, and help us make an impact on the world!

MongoDB is committed to providing any necessary accommodations for individuals with disabilities within our application and interview process. To request an accommodation due to a disability, please inform your recruiter.

MongoDB is an equal opportunities employer.

Red ID: 2273504602

AI is used to review applications based on job-related criteria and does not replace human decision-making. The hiring team decide who moves forward.

MongoDB’s base salary range for this role is posted below. Compensation at the time of offer is unique to each candidate and based on a variety of factors such as skill set, experience, qualifications, and work location. Salary is one part of MongoDB’s total compensation and benefits package. Other benefits for eligible employees may include: equity, participation in the employee stock purchase program, flexible paid time off, 20 weeks fully-paid gender-neutral parental leave, fertility and adoption assistance, Registered Retirement Savings Plan (RRSP) with employer match, mental health counseling, backup child and elder care, and health, dental, and vision benefits offerings. Please note, the base salary range listed below and the benefits in this paragraph are only applicable to candidates based in Canada.

MongoDB’s base salary range for this role in Canada is:
$108,000$149,000 CAD

Frequently Asked Questions

What is the salary for the Software Engineer 3 role at mongodb?
The listed salary for this Software Engineer 3 position at mongodb is CAD 108K–149K. This is an full-time role.
Where is the Software Engineer 3 position at mongodb located?
This Software Engineer 3 role at mongodb is based in Alberta; British Columbia; Manitoba; Nova Scotia; Ontario; Quebec. The position is listed as on-site or hybrid. Check the full job description or apply directly to confirm the work arrangement.
Which team or department does the Software Engineer 3 at mongodb belong to?
This Software Engineer 3 position is part of the AI Builder Experience department at mongodb. See the full job description for more information about the team structure and responsibilities.
How do I apply for the Software Engineer 3 position at mongodb?
Click the "Apply Now" button on this page. You will be redirected to mongodb's official application portal hosted on greenhouse where you can submit your application directly.
When was the Software Engineer 3 job at mongodb posted?
This Software Engineer 3 position at mongodb was posted on Aug 5, 2026. Apply as soon as possible — early applications are often reviewed first.
Software Engineer 3
mongodb · 💰 CAD 108K–149K
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