In this episode of 1 to 100, Alex Beller from Postscript joins us to talk about rebuilding a scaled SaaS company from scratch with AI coding agents, moving from SMS into a broader marketing platform, and managing the organizational change that follows. Postscript has about 20,000 customers, an application shaped by eight years of work, and roughly 50 engineers. Alex explains why Adam started rebuilding the product alone as an experiment, then turned it into the company’s new direction after seeing what AI-native development could do. The new product, first called Acorn, competed with Oak, the existing Postscript platform. The company eventually decided to move all customers to Acorn and call it Postscript 2.0. Alex says the new codebase created a 10x to 50x improvement in speed and capacity compared with the old system. That rebuild also changed the product strategy. Email is no longer an add-on to an SMS platform. Email, SMS, and other channels are part of an AI-native CRM. Alex explains why starting from scratch made this multi-channel product easier to build. The internal transition was difficult. Some employees were excited by the new direction. Others were skeptical because the original system contained years of their work, including mistakes made by the founding team. Postscript gave people time to adjust, but some employees left and the company made proactive leadership changes. We also talk about the difference between adding AI to an old workflow and building around AI from the start. Alex argues that old CDPs are built around passive, structured data. The new system uses brand context, customer behavior, reviews, surveys, and results from ongoing experiments to create more proactive and personalized messages. Alex expects this to create revenue gains as well as cost savings. He describes a possible future where a small retention team can manage more work without an agency, while the software handles more of the campaign creation and orchestration. Adoption will take time. The product still needs to connect with familiar tools such as a brand’s marketing calendar and help teams move toward this new operating model. The lesson for SaaS founders is that some AI transformations may require a founder-led rebuild from scratch. One high-agency founder can build the new system while the rest of the company runs the existing business. It is painful and demanding, but it may be the fastest way to escape the constraints of an old product and old operating model. Chapters00:00 Cold open: tech at home, staying offline01:53 The co-CEO experiment and Adam going quiet04:10 Rebuilding Postscript from scratch08:03 Migration, the email launch, and multi-channel08:59 Telling the team: skeptics and change management12:30 Managing believers and leavers14:47 A customer churns for email and SMS17:35 Identity, dilution, and the advisory board19:54 Investors, category outcomes, business health23:02 Bolt-on AI versus AI-native26:00 Retention teams, agencies of one, revenue alpha28:48 Adoption stories: FERMAT and Foreplay34:16 Advice for founders: the rebuild playbook39:34 Hiring after the rebuild