Senior Python Developer Jobs in Mississauga, ON (NOW HIRING)

Venture outside the ordinary - TMX Careers

The TMX group of companies includes leading global exchanges such as the Toronto Stock Exchange, Montreal Exchange, and numerous innovative organizations enhancing capital markets. United as a global team, we're connecting cross-functionally, traversing industries and geographies, moving opportunity into action, advancing global economic growth, and propelling progress. Through a rich exchange of ideas, meaningful collaboration, and a nimble operating model, we're powering some of the nation's most critical systems, fueling capital formation and innovation, bringing increased opportunity to business visionaries, product ingenuity to consumers, and career exploration to our team.

Ready to be part of the action?

Where the velocity of high-frequency trading meets the agility of modern cloud engineering, the TMX DataXchange Squad serves as a vital pillar of Canada's capital markets. The team is responsible for developing and managing month-end billing across all TMX markets-including equities, derivatives, and Canadian Depository Clearing Services. Additionally, the squad oversees the creation of settlement files for all TMX equity markets, ensuring that millions of trades are delivered to the CDS (Canadian Depository Services) for timely and accurate settlement.
We are looking for a versatile Senior Software Engineer to join our core team and help us build and maintain high-quality software. You will be a key contributor across our entire technical stack, working on everything from backend logic and data management to user-facing features.
The ideal candidate is a well-rounded developer who enjoys using the right tool for the job-whether that's writing Java or Python, managing SQL databases, or deploying projects to the Cloud (AWS/GCP/Azure). We value developers who stay efficient by leveraging AI agentic tools to speed up their workflow and automate routine tasks.
This role reports to: Senior Manager and Squad Lead, DataXchange Squad
This role is hybrid (2-3 days/week in the office) - based in Toronto, ON.

Key Responsibilities:

• Develop and implement high-performance C++ applications, ensuring code efficiency and system reliability.

• Lead code reviews, mentor junior engineers, and contribute to high-level architectural decisions that define the product's future.

• Develop sophisticated scripts (Python, Bash) to automate repetitive tasks, optimize CI/CD pipelines, and manage system monitoring.

• Debug and resolve complex production issues across the full stack, from application logic down to the database layer.

• Provide Tier-3 technical support for critical production escalations when required.

• Debug complex production issues across various layers of the stack, from the application level down to database.

Required Skills & Qualifications

• 5-6 years of professional experience with C++ (familiarity with modern standards like C++17/20 is a plus).

• 3-4 years of practical experience with Python, SQL, and Perl for system automation and data manipulation.

• Proven experience with containerized application development (Docker/Kubernetes) within AWS, GCP, or Azure.

• Solid understanding of CI/CD pipelines and IaC tools such as Terraform or CloudFormation.

• A proactive interest in leveraging AI Agents and LLM-based tools (e.g., GitHub Copilot, Cursor) to accelerate development speed and automate routine tasks.

• A self-starter with excellent communication skills, capable of working independently in a fast-paced, dedicated team environment.

• University degree in Computer Science, Information Technology, or a related field.

Nice to haves:

• Ability to work in a flexible environment and interest in continuous process improvement

• Sense of organization, focus, persistence and ability to work according to an established plan and deadline

• Excellent interpersonal skills and team player

• Ability to manage multiple tasks and deadlines

• Imagination and creativity in developing solutions

• Analytical and effective problem solver

This role is hybrid (2 - 3 days in the office) - based in Toronto, ON.

Salary Range: 120,000/year -130,000/year CAD

Please note that the salary range included is a guideline only. The salary offered may vary based on factors, including, but not limited to, the successful candidate's relevant knowledge, skills, and experience

The recruiting efforts for this role are intended to fill a vacant position

In the market for...

Excitement - Explore emerging technology and innovation, as well as ventures and digital finance that shape the future of global markets! Experience the movement of the market while grounded in the stability of close to 200 years of success.

Connection - With site hubs in some of the world's most multicultural cities, we leverage our size and structure to create rich connections and belonging while experiencing powerful global impact through our work.

Impact - More than a platform, we use our talents to power mission-critical systems that drive global economic advancement, innovation, and growth. As well, our employee-led Team Impact spreads social good via our giving strategy.

Wellness - From empathetic leadership to a culture of flexibility and balance, we believe wellness at work creates the maximum yield and a stronger "we". Plus, with a cloud-first and hybrid workstyle, as well as generous time-off and leaves, we support a life well lived!

Growth - From a growth mindset in our work, to expansion in our business, TMX is home to action-takers energized by the achievement of ambitious growth.

Ready to enrich your career with impactful work, leaders who truly care, and the flexibility and programs to help you thrive as part of #TeamTMX ? Apply now.

Please note that our company is not currently sponsoring work permit applications and the applicant must be authorized to work in the country where this position is located.

TMX is committed to creating and sustaining a collegial work environment in which all individuals are treated with dignity and respect and one which reflects the diversity of the community in which we operate. We provide accommodations for applicants and employees who require it.