Here collection of good articles / blog posts for Extension framework. I just completed the customization using extension. Initially, it’s really tough for me. But with passage of time and my library of code snippet increased, I  felt the power of extensions over old classic overlay concept. Even I used extension in custom forms instead write old age methods in controls and data sources. Here are some  links which are very helpful for me and worth to share. Event handling: https://us.hitachi-solutions.com/knowledge-center/customize-dynamics-365-user-interface-extension-event-handler/ https://community.dynamics.com/365/financeandoperations/b/newdynamicsax/archive/2016/10/11/code-behind-extension-forms-how-to-add-state-variable-and-override-methods-without-overlayering https://community.dynamics.com/ax/b/dynamicsaxconcoction/archive/2017/05/17/d3fo-customizing-interaction-classes-using-extensions https://devserra.wordpress.com/2016/04/19/ax7-using-table-event-handler/ https://community.dynamics.com/365/financeandoperations/b/howtodynamics365/archive/2018/04/24/how-to-create-display-method-for-table-extension-in-dynamics-365 https://axility.net/en/access-stuff-in-the-new-event-subscriptions/ Workflow: http://d365technext.blogspot.com/2018/07/avoid-over-layering-in-development-of.html https://community.dynamics.com/365/financeandoperations/b/nareshsdynamicsaxblog/archive/2017/03/15/create-custom-workflow-in-d365-dynamics-365 https://devmusings.blog/2018/03/18/custom-workflows-in-microsoft-dynamics-365-for-operations/ https://community.dynamics.com/365/financeandoperations/b/dynamics365foaxhub/archive/2018/10/06/create-custom-workflow-participant-assignment-provider-type-in-ax-2012 https://workflowax.wordpress.com/2009/10/30/participant-provider-example/ https://www.lexisnexis-es.co.uk/blog/2018/10/22/workflows-in-microsoft-dynamics-365-for-finance-and-operations/ Model: https://stoneridgesoftware.com/what-is-the-modelutil-exe-good-for/ https://community.dynamics.com/365/financeandoperations/f/765/t/223547 https://www.cloudfronts.com/model-importexport-in-dynamics-365-operations/ https://docs.microsoft.com/en-us/dynamics365/unified-operations/dev-itpro/dev-tools/models-export-import Email templates https://www.sikich.com/insight/how-to-email-purchase-orders-in-dynamics-365-for-operations/ Vendor Collaboration: https://gfeaxblog.wordpress.com/2018/05/16/vendor-collaboration-in-microsoft-dynamics-365-for-finance-and-operations/ Reports through extension: https://docs.microsoft.com/en-us/dynamics365/unified-operations/dev-itpro/analytics/custom-designs-business-docs https://blogs.msdn.microsoft.com/dynamicsaxbi/2017/01/02/customizing-app-suite-reports-using-extensions/ https://docs.microsoft.com/en-us/dynamics365/unified-operations/dev-itpro/analytics/customize-app-suite-reports-with-extensions Custom form: https://dynamicsaxinsight.wordpress.com/2017/06/23/ax7-d365-operations-create-details-master-pattern-form/