Jonathan Demers, Developer in Montreal, QC, Canada
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Jonathan Demers

Verified Expert  in Engineering

Software Developer

Montreal, QC, Canada
Toptal Member Since
November 15, 2021

Jonathan is a creative, hands-on leader. He has extensive experience in software engineering in the banking, finance, insurance, and R&D spaces, delivering multiple high-profile projects. He is a strategic decision-maker with a propensity to perform in fast-paced environments and is an inspiring and highly technical model for other leaders and teams. Morgan Stanely, the Canadian Space Agency, Desjardins, and the National Bank of Canada have all benefitted from Jonathan's expertise.


National Bank of Canada
Java 11, Spring Boot, React, TypeScript, REST, OAuth 2, GraphQL, MariaDB...
TD Bank Group
Java, Spring, Apache Maven, JBoss, OAuth 2, REST, SOAP, Angular, TypeScript...
Mule ESB, Java, JPA, MariaDB, REST, JSON, OAuth 2, JSON Web Tokens (JWT), Auth0...




Preferred Environment

Java, React, REST, SQL, NoSQL, OAuth 2, Node.js, JavaScript, TypeScript, Spring Boot

The most amazing... banking and instant messaging solutions I've delivered for Thales improved performance and stability of the back end up to 1,000 tx/second.

Work Experience

Full-stack Developer Lead (Consultant)

2020 - PRESENT
National Bank of Canada
  • Led an agile team of front-end, back-end, SQL, and test-automation developers.
  • Recruited, onboarded, motivated, assigned tasks, unblocked, and evaluated the performance of team members.
  • Advised on project estimates and delivery planning.
  • Completed hands-on development on the back end, front end, and CI/CD pipeline.
Technologies: Java 11, Spring Boot, React, TypeScript, REST, OAuth 2, GraphQL, MariaDB, Sybase, Apache Maven, NPM, OpenShift, Kubernetes, Docker, Jenkins, Git, Agile, Selenium, Java

Developer Lead (Consultant)

2018 - 2020
TD Bank Group
  • Led teams of developers and DevOps on numerous successful enterprise projects.
  • Advised the department senior director on organizational matters.
  • Facilitated communications between business stakeholders and technical teams.
  • Conducted hands-on development on the back end (Java and Node.js), CI/CD pipeline, and some front end.
Technologies: Java, Spring, Apache Maven, JBoss, OAuth 2, REST, SOAP, Angular, TypeScript, Node.js, PM2, NPM, Oracle, RHEL, Linux, Git, Jenkins, Ansible, Agile

Senior Software Engineer (Consultant)

2017 - 2018
  • Contributed to the architecture and development of the online financing platform for businesses.
  • Integrated with multiple external systems, including SalesForce and Equifax.
  • Contributed to the automated API test suite build with JMeter.
Technologies: Mule ESB, Java, JPA, MariaDB, REST, JSON, OAuth 2, JSON Web Tokens (JWT), Auth0, Swagger, Spring Boot, Elasticsearch, Docker, Apache Maven, Anypoint Studio, Eclipse IDE, Git, Jenkins, Jira, Apache JMeter

Senior Software Engineer and Architect (Consultant)

2008 - 2017
Various Clients
  • Designed, developed, hosted, and maintained the TERNingpoint quote and policy management system for TERN Financial Group as the senior software engineer and architect (2014-2021).
  • Served as a senior software engineer at Morgan Stanley. Managed a team while completing an NDA project (2015-2017).
  • Contributed to the development of a new insurance policy management system with service oriented architecture (SOA back end) for Intact Insurance as the senior software engineer (2013-2014).
  • Contributed to the architecture and development of the new fixed income trading platform Bond Trader for Industrial Alliance Securities as the senior software engineer (2013). Multiple system integrations included Bloomberg TOMS, CBID trading platform, and IBM ISM (SIS).
  • Led back-end development of a new online trading platform (stocks, options, mutual funds, etc.) for Desjardins as the tech lead and senior software developer (2012-2013 and 2010-2011).
  • Developed mobile banking and instant messaging solutions on the back end and front end (Android) for Gemalto (now Thales) as the senior software engineer (2011-2012 and 2008-2009). Improved performance and stability of the back end up to 1,000 tx/second.
  • Migrated and enhanced several financial applications from the IBM ISM platform to Broadridge platform for Penson Financial Services as the senior software developer (2010).
Technologies: Java, Jakarta EE, Apache Maven, Spring, OSGi, JPA, Hibernate, FIX Protocol, JSch, Apache Struts, Apache Tomcat, Jetty, Mule ESB, WebSphere, Jenkins, Apache JMeter, REST, JSON, JAXB, Web Services Description Language (WSDL), XSD, MySQL, Oracle, Microsoft SQL Server, Elasticsearch, HTML, CSS, Bootstrap, jQuery, Cloud, Amazon Web Services (AWS), Amazon EC2, Amazon RDS, Amazon Virtual Private Cloud (VPC), DNS, Transport Layer Security (TLS), Certbot, Linux, Ubuntu, Red Hat Linux, Debian, Eclipse, Android SDK, Git, Jira

From Intern to Senior Software Developer and Architect (Employee)

2001 - 2008
Various Employers
  • Developed, architected, and customized supply chain management applications for clients. Started as a software developer in R&D and was promoted to solutions architect in the Custom Enhancement division at Tecsys (2006 - 2008).
  • Created a distributed financial system for trade allocation of fixed income securities at Morgan Stanley as a systems architect (2004 - 2006).
  • Built many applications for clients from CMS to custom eCommerce solutions at Logient as a software developer (2002 - 2004).
  • Developed real-time software and hardware integration for an underwater robot at the Institut de recherche d'Hydro-Quebec as a software developer (2002) to inspect hydroelectric dams.
  • Developed a testbed to measure the performance of spatial RF communication modules for the Canadian Space Agency as an intern (2001).
Technologies: Java, Jakarta EE, Apache Tomcat, JBoss, WebSphere, Java Servlets, Jakarta Server Pages (JSP), Taglibs, HTML, JavaScript, XML, DTD, XSLT, XPath, JAX-WS, SOAP, MQSeries, Linux, AIX, Oracle, IBM Informix, Sybase, PostgreSQL, MATLAB, C++, Inertial Navigation System (INS), Kalman Filtering, QNX, Real-time Operating System (RTOS)

TD MyInsurance
TD MyInsurance provides customers with a simple way to review their policy, make changes, or check on the status of a claim. It's a secure online service that allows them to manage and review their home and car insurance policies and get answers to commonly asked questions from our information center.


The system allowed customers to follow and maintain their insurance products 24/7, improving customer service and customer satisfaction while reducing the load on call centers.

I led back end developers and DevOps teams of this product. I also conducted hands-on development on the back end (Java and Node.js), CI/CD pipeline, and some front end.

DevConnector - MERN Stack Front to Back
A complete MERN stack application from the hands-on course "MERN Stack Front To Back: Full Stack React, Redux & Node.js" by Brad Traversy.

The application features additional improvements outside of the course: CORS, a front end deployed in CDN (GitHub Pages), upgraded to React Router v6, and extra bug fixes.
1998 - 2002

Bachelor of Engineering Degree in Engineering

Polytechnique Montreal - Montreal, Canada


MERN Stack Front To Back



TensorFlow Developer



Deep Learning



Leading People and Teams

University of Michigan


JAXB, React, Node.js, JMS, jQuery, TensorFlow, Keras, Pandas, NumPy, Matplotlib, Java Servlets, Taglibs, JAX-WS, GitHub API


Jenkins, Git, Apache Tomcat, Eclipse IDE, Certbot, Apache Maven, NPM, ActiveMQ, Apache JMeter, MQSeries, IBM MQ, Ansible, PM2, Auth0, Anypoint Studio, Jira, SBT, Autosys, Jetty, Amazon Virtual Private Cloud (VPC), MATLAB, GitHub Pages


OAuth 2, Spring Boot, Spring, Hibernate, JSON Web Tokens (JWT), Jakarta Server Pages (JSP), Bootstrap, Selenium, JPA, Swagger, Spring 5, Angular, OSGi, Apache Struts, Android SDK, Express.js, Redux


Java, SQL, Bash Script, Java 11, XML, XPath, Java 6, JavaScript, TypeScript, HTML, Web Services Description Language (WSDL), XSLT, Python, CSS, GraphQL, Scala, XSD, C++


REST, Agile


Linux, Amazon EC2, Ubuntu, Debian, Eclipse, Amazon Web Services (AWS), Docker, Oracle, WebSphere MQ, Jakarta EE, Red Hat Linux, Kubernetes, OpenShift, JBoss, Mule ESB, WebSphere, AIX, Heroku


JSON, MariaDB, PostgreSQL, MySQL, NoSQL, Sybase, Elasticsearch, IBM Db2, Microsoft SQL Server, IBM Informix, MongoDB


Leadership, Talent Management, Team Leadership, Programming, Software Engineering, Cloud, DNS, Transport Layer Security (TLS), SOAP, Optimization, FIX Protocol, Amazon RDS, Deep Learning, RHEL, Influencers, Software, Electronics, Artificial Intelligence (AI), Machine Learning, Convolutional Neural Networks (CNN), Natural Language Processing (NLP), Time Series, Prediction Markets, Neural Networks, Hyperparameters, Regularization, Sequence Models, Kerberos, JSch, DTD, Inertial Navigation System (INS), Kalman Filtering, QNX, Real-time Operating System (RTOS), CORS, Axios, Generative Pre-trained Transformers (GPT)

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