Backend Python Developer Jobs in London, ON
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London, ON
Senior Backend Python Developer
Senior Backend Python Developer
Backend Software Developer - North America
Backend Software Developer - North America
Sr Python Developer/Engineer ( AI )
Sr Python Developer/Engineer ( AI )
Senior Application Developer- Python (Global Security)
Senior Application Developer- Python (Global Security)
Java Backend Developer
Java Backend Developer
Senior Full-Stack Developer
Senior Full-Stack Developer
Senior Developer (Backend) - Commerce Platform
Senior Developer (Backend) - Commerce Platform
Senior Fullstack Developer (AI)
Senior Fullstack Developer (AI)
Specialist - Data Engineering
Specialist - Data Engineering
Principal Backend Software Developer
Principal Backend Software Developer
Senior Backend Java Microservices Engineer role (Enterprise level)
Senior Backend Java Microservices Engineer role (Enterprise level)
Python & Large Language Model (LLM) Developer - Operate
Python & Large Language Model (LLM) Developer - Operate
Mobile Developer
Mobile Developer
Full Stack Developer
Full Stack Developer
Senior Automation Developer
Senior Automation Developer
Senior Full-Stack Developer, No-Code Team
Senior Full-Stack Developer, No-Code Team
Back-end Engineer
Back-end Engineer
API Platform Architect / Lead Backend Engineer (Golang)
API Platform Architect / Lead Backend Engineer (Golang)
Software Developer (Laravel/Symfony | Senior-Level Experience)
Software Developer (Laravel/Symfony | Senior-Level Experience)
Intermediate Software Developer - .NET / AWS / Full Stack
Intermediate Software Developer - .NET / AWS / Full Stack
Top Benefits
About the role
Location:
London, ON
Date Posted:
Mar 23, 2026
##Job Description
###Join a Successful and Growing Data Company
Cleanlist isCanada’s leading customer data company— and we’re on a mission to rid the world of bad customer data. We help hundreds of organizations clean, enrich, and acquire the data they need to drive marketing ROI, operational efficiency, and business growth. Our clients include some of the country’s most recognized brands — Costco, Loblaw, Rogers — and many others who trust us to power their customer data strategies.
Now, we’re scaling to the next level. To get there, we need aSenior Backend Python Developerwho can help Cleanlist stay on the leading edge with great products and infrastructure.
This is not a "ticket-taking" role. You will be working directly with our Lead Architect to analyze business problems, design secure solutions, and build them. While your focus will be heavy on the Backend (Python), you must be comfortable handling basic UI work (templating/CSS) to ship complete features.
As a SOC2 certified company, we prioritize security while maintaining a fast-paced development lifecycle. We are also beginning to explore AI and LLM integrations, making this an exciting time to join if you are looking to expand your skillset in that direction.
###What You’ll Do
-**Backend Development:**Build robust, scalable applications using Python (Django & Flask). -**Systems Analysis:**Work with the Lead Architect to break down vague requirements into concrete technical specs. -**Database Management:**Design efficient schemas and write optimized queries for PostgreSQL. -**Security & Compliance:**Write code that adheres to SOC2 controls and OWASP security standards. -**Basic Frontend:**Handle server-side rendering and templating (Jinja2/Django Templates) and basic CSS layout—no complex JavaScript frameworks required. -**Infrastructure:**Assist in deploying and monitoring services on AWS. -**AI Exploration:**Assist in integrating our existing ML model and help research future LLM implementations.
###What You Bring
-**Experience:**Minimum 5+ years of professional software development experience. -**Language:**Expert proficiency in Python. -**Data:**Strong proficiency with PostgreSQL (complex queries, optimization, schema design). -**Frameworks:**Solid experience with Django and Flask. -**Concurrency:**Understanding of Asynchronous programming in Python. -**Security:**A security-first mindset. You understand why inputs must be sanitized and why least-privilege access matters. -**Communication:**Clear, professional English communication skills (written and verbal). You can document your code and your decisions.
####Nice to Have
-**AI/ML Interest:**Previous exposure to Machine Learning concepts or LLM APIs. -**Compliance:**Previous experience working in a SOC2, HIPAA, or ISO 27001 environment.
###Our Tech Stack
-**Backend:**Python, Pandas, Django, Flask, Asyncio -**Database:**PostgreSQL -**Infrastructure:**AWS, Git -**Frontend:**HTML, CSS, Server-side Templates
###Why Cleanlist?
At Cleanlist, our culture is built on values that make us different:
-Think Like a Customer — Be the Solution -Systems Set Us Free — We scale through process and automation -We’re Here to Grow — as people and as a company -Curiosity Solves Problems — If we don’t know, we figure it out
We’re a tight-knit, growth-driven team that prizes innovation, collaboration, and everyday impact. You’ll join a company where your ideas matter, your work drives real results, and your career can grow as fast as Cleanlist itself.
###What We Offer
-Competitive compensation tied to results. -Comprehensive benefits: health, dental, and drug coverage. -A chance to make a direct, visible impact on Cleanlist’s client relationships and growth trajectory.
###How to Apply
If this role speaks to you, we’d love to hear why. Send us your resume — but more importantly, tell us in your cover letter why you’re the right person to help Cleanlist clients succeed. Please include your salary expectations and availability to start.
Click below to apply and start shaping the future of Cleanlist.
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