Backend Engineer, AI/ML

We're looking for a Backend Engineer to join our team in Toronto to work on LLM-powered search and retrieval agents. In this role, you will build and optimize the retrieval infrastructure, APIs, and data pipelines that power our ML team’s agentic workflows, enabling fast, accurate, and scalable retrieval for advanced user-facing systems.

Q: Klue who?

A: Klue is a VC-backed, capital-efficient growing SaaS company. Tiger Global and Salesforce Ventures led our US$62m Series B in the fall of 2021. We’re creating the category of competitive enablement: helping companies understand their market and outmaneuver their competition. We benefit from having an experienced leadership team working alongside several hundred risk-taking builders who elevate every day.

We’re one of Canada’s Most Admired Corporate Cultures by Waterstone HC, a Deloitte Technology Fast 50 & Fast 500 winner, and recipient of both the Startup of the Year and Tech Culture of the Year awards at the Technology Impact Awards.

Q: What are the responsibilities, and how will I spend my time?

You will work closely with machine learning engineers, ensuring our backend systems can support rapid experimentation while remaining production-ready.

What you’ll do on a day to day basis

• Design, implement, and maintain retrieval infrastructure and APIs that interface seamlessly with LLM-based agent workflows.

• Integrate dense retrieval, hybrid retrieval, and re-ranking models into live systems.

• Optimize latency, scalability, and throughput of retrieval systems for real-time agentic pipelines.

• Build and maintain vector database infrastructure (FAISS, Milvus, Weaviate, Pinecone, PGVector) and traditional search engines (Elasticsearch, OpenSearch).

• Support retrieval-augmented generation (RAG) workflows, including efficient query execution, chunk retrieval, and caching strategies.

• Develop monitoring and observability tools for retrieval pipelines to ensure reliability and transparency.

• Work with ML engineers on data pipelines for indexing and re-indexing, enabling continuous improvement of search relevance.

• Contribute to the architecture of multi-step retrieval agents, ensuring clean abstractions between the backend and ML layers.

Q: What experience are we looking for?

• 3+ years of backend engineering experience, ideally in search, retrieval systems, or high-scale APIs.

• Strong programming skills in Python, Ruby, or similar backend languages.

• Experience with search infrastructure (Elasticsearch, OpenSearch, Vespa) and vector search systems.

• Understanding of retrieval pipelines, dense retrieval, and hybrid search.

• Familiarity with real-time data pipelines (Kafka, Pub/Sub) for indexing workflows.

• Experience with distributed systems and microservices, with a focus on reliability and performance.

• Familiarity with cloud infrastructure (AWS, GCP, Azure) and container orchestration (Kubernetes).

• Ability to work collaboratively with ML Engineers, understanding their experimentation workflows and constraints.

• Strong debugging and profiling skills for production systems.

Nice to Have

• Experience with retrieval-augmented generation (RAG) or agentic retrieval workflows.

• Exposure to prompt engineering and LLM system integration.

• Contributions to open-source projects in search or retrieval.
  

Q: What makes you thrive at Klue?

A: We're looking for builders who:

• Take ownership and run with ambiguous problems

• Jump into new areas and rapidly learn what's needed to deliver solutions

• Bring scientific rigor while maintaining a pragmatic delivery focus

• See unclear requirements as an opportunity to shape the solution

Q: What technologies do we use?

• LLM platforms: OpenAI, Anthropic, open-source models

• ML frameworks: PyTorch, Transformers, spaCy

• Search/Vector DBs: Elasticsearch, Pinecone, PostgreSQL

• MLOps tools: Weights & Biases, MLflow, Langfuse

• Infrastructure: Docker, Kubernetes, GCP

• Development: Python, Git, CI/CD

Q: What is your working style at Klue?

• Hybrid. Best of both worlds (remote & in-office) You and your team will be in the office 2 days a week.

• Our main Canadian hubs are in Vancouver and Toronto, and most of our teams are located in EST and PST.

Q: What about Compensation & Benefits:

• Competitive base salary

• Benefits. Extended health & dental benefits that kick in Day 1

• Options. Opportunity to participate in our Employee Stock Option Plan

• Time off. Take what you need. Just ensure the required work gets done and clear it with your team in advance. The average Klue team member takes 2-4 weeks of PTO per year.

• Direct access to our leadership team, including our CEO

⬇️ ⬇️ ⬇️ ⬇️ ⬇️ ⬇️ ⬇️ ⬇️ ⬇️ ⬇️

Not ticking every box? That’s okay. We take potential into consideration. An equivalent combination of education and experience may be accepted in lieu of the specifics listed above. If you know you have what it takes, even if that’s different from what we’ve described, be sure to explain why in your application.

At Klue, we're dedicated to creating an inclusive, equitable and diverse workplace as an equal-opportunity employer. Our commitment is to build a high-performing team where people feel a strong sense of belonging, can be their authentic selves, and are able to reach their full potential. If there’s anything we can do to make our hiring process more accessible or to better support you, please let us know, we’re happy to accommodate.

We’re excited to meet you and in the meantime, get to know us:

🌈 Pay Up For Progress & 50 - 30 Challenge

✅✅ Win-Loss Acquisition (2023)

🐅 Series B (2021)

🏆 Culture, culture, culture!

🎧 Winning as Women & More!

🐝 About Us

🥅 Product Demo Arena

🔍 Glassdoor

🎥 Youtube

☕️ LinkedIn

🦄 Wellfound (AngelList)