Tern Stories

Code migration is transforming how modern software is built, but few are talking about the risks that come with it.In this episode, we explore how code migration is reshaping API security, infrastructure, and the very foundations of enterprise development.From GraphQL to AI-driven architecture, we uncover what’s really happening behind the buzzwords, and why companies are struggling to keep their systems secure during massive migrations.Whether you’re a developer, architect, or engineering leader, this conversation reveals the hidden trade-offs of code migration, the growing complexity it introduces, and how to protect your systems before it’s too late.If you’re planning your next modernization effort or already knee-deep in legacy refactors, this is a must-watch. We break down practical lessons, real-world examples, and strategies to make code migration work for you, not against you.Get Tern Stories in your inbox: https://tern.sh/youtube

In this episode, we dive into Snapchat’s bold code migration, a project that reshaped the way their app runs at scale.This code migration wasn’t just about rewriting code, it was about survival, speed, and creating a leaner system that could handle hundreds of millions of users.You’ll hear how the team faced challenges like supporting long-dead features, rebuilding APIs bug-for-bug, and even migrating conversations instead of entire users.These behind-the-scenes stories reveal the hidden complexity of a massive code migration and the lessons that can help any engineering team facing similar challenges.Whether you’re an engineer, a founder, or just fascinated by how the biggest apps in the world evolve, this deep dive into code migration will show you what it really takes to pull off a technical transformation at scale.Connect with Ben Hollis ➡️ https://stately.cloud/Get Tern Stories in your inbox: ➡️ https://tern.sh/youtube

Code migration is one of the toughest challenges engineers face at scale. In this episode, we dive deep into a real-world code migration that powered millions of queries daily.You’ll hear how Sourcegraph rebuilt their core parser, the testing strategies that prevented disasters, and why “unglamorous engineering” is often the work that matters most. From differential testing to temporary safety nets, this story shows how code migration can be done without breaking everything.Whether you’re planning a refactor, facing a large-scale rewrite, or just curious about engineering under pressure, the lessons here will help you approach your next code migration with confidence.Get Tern Stories in your inbox: https://tern.sh/youtube

Code migration isn’t hard because the code is complex, it’s hard because the real problems only reveal themselves once you’re already in the middle of it.In this episode, I break down why code migration projects so often drag on for months or years, and how AI can change that story completely.From Stripe and Pinterest to Airbnb, Zapier, Twitter, and Slack, you’ll see how teams faced huge migration challenges, and how better planning, faster learning, and smarter communication turned the tide.I’ll share lessons on why every code migration is unique, how small overlooked details can derail entire timelines, and how AI can uncover those issues before they blow up.If you want your next code migration to feel less like chaos and more like a smooth, predictable process, this episode will give you the roadmap.Get Tern Stories in your inbox: https://tern.sh/youtube

When a critical code migration goes wrong, the stakes can be nothing short of catastrophic.In this episode, we dive into the code migration that almost brought one of the world’s largest social platforms to its knees.You’ll hear the inside story of how engineers raced against time to prevent total failure, the technical hurdles that made this code migration uniquely challenging, and the high-pressure decisions that determined success or disaster.We break down the lessons learned, the strategies that worked, and how these insights can prepare you for your own future code migration.If you’ve ever wondered what happens when code migration becomes a matter of survival, this is the episode you can’t afford to miss.Get Tern Stories in your inbox: https://tern.sh/youtube

Code migration isn’t just a technical task, it’s a minefield.In this episode, we dive into a real-world code migration story from Slack that uncovered terrifying truths lurking deep in the system.From multi-user duplication chaos to security incidents hiding in plain sight, this is code migration at its most high-stakes.You’ll hear how Slack’s “Storm Chasers” team tackled six massive code migration prongs, rewrote critical data models, and avoided taking down the entire platform, all while operating at enterprise scale.If you’ve ever touched a legacy system, dealt with user provisioning, or tried to clean up a years-old data mess, this is your masterclass in what code migration really looks like.Whether you’re a staff engineer, EM, or just trying to survive your company’s next code migration, don’t miss this.Get Tern Stories in your inbox: https://tern.sh/youtubeConnect with Sarah:   linkedin.com/sarah-mann-14758844  

Code migration sounds like a technical task, but it’s a strategic minefield.In this episode, we explore how code migration projects fail not because of bugs, but because of broken decision-making and unclear architecture.You’ll hear about raw stories from engineers at Slack, Datadog, and other world-class teams who’ve battled through the chaos of code migration under pressure.If you’re relying on AI to do the thinking for you, this episode will make you rethink everything.Whether you’re planning a rewrite or deep in the trenches, you’ll learn how to survive your next code migration, and maybe even lead one right.Get Tern Stories in your inbox: https://tern.sh/youtube

Code migration sounds like a technical task, but it’s a strategic minefield.In this episode, we explore how code migration projects fail not because of bugs, but because of broken decision-making and unclear architecture.You’ll hear about raw stories from engineers at Slack, Datadog, and other world-class teams who’ve battled through the chaos of code migration under pressure.If you’re relying on AI to do the thinking for you, this episode will make you rethink everything.Whether you’re planning a rewrite or deep in the trenches, you’ll learn how to survive your next code migration, and maybe even lead one right.Get Tern Stories in your inbox: https://tern.sh/youtube

Code migration doesn’t have to be slow and painful. In this episode, Madeline and I break down a proven method to speed up your code migration process without sacrificing code quality or stability.You’ll learn actionable insights from a real-world team who successfully tackled code migration at scale, and did it faster than most thought possible!If you’re planning a code migration, currently in one, or trying to avoid the common pitfalls, this episode is packed with the perspective you need.Let's break down a real world example with Madeline, which is a smarter way to approach your code migration strategy and accelerate delivery without cutting corners!Get Tern Stories in your inbox: https://tern.sh/youtubeConnect with Madeline!➡️ https://www.linkedin.com/in/madelineshortt/

Tom Elliott joined Yext in 2015 as an iOS developer. Within a year, both his mobile projects were canceled.But Tom's career crisis was nothing compared to what was happening with Yext's infrastructure. The company was hitting the limits of homegrown tools built by ex-Google engineers who had recreated their own version of Borg called Khan. It worked when Yext was small. Now they were running thousands of microservices—Tom calculated they had a higher microservice-to-employee ratio than Uber.The real breaking point? Server upgrades. Every time the infrastructure team needed to upgrade a machine, they had to manually edit code to move services off, do the upgrade, then edit code again to move everything back."Everything was manually configured as to where things lay," Tom recalls.Khan had been built by "one or two people" as a coalition of the willing.Now Yext had grown past 20 teams, and adding the features they desperately needed—like automatic workload migration—would require massive investment in a homegrown system.---Get Tern Stories in your inbox: https://tern.sh/youtubeConnect with Tom! : https://www.ocuroot.com/

IBM was dropping RethinkDB support. No migration path. No alternatives. Just an end date.Andy Monroe's team at LaborChart had five engineers and an entire construction scheduling platform built on a database that was already dead. They'd watched every other RethinkDB hosting provider shut down, leaving only Compose.io.When IBM acquired Compose, they knew it was just a matter of time.Andy's air conditioning had died two hours before our interview. It was 90 degrees in Kansas, and as we talked about this moment, the irony wasn't lost on either of us.The company he'd helped build solved scheduling problems for construction workers—the very people who might have fixed his AC. Now he had a different kind of emergency to handle.Get Tern Stories in your inbox: https://tern.sh/youtubeConnect with Andy! - andymonroe.dev

Back in 2011, PagerDuty had a problem that would make any infrastructure engineer wince: they were using MySQL as a queue. In this episode, we dive into the fascinating journey of using Cassandra as a queue, the challenges faced, and the lessons learned along the way.Arup Chakrabarti, former Senior Director of Engineering at PagerDuty, shares his insights on the early days of the company, the technical decisions made, and how they navigated the complexities of using a NoSQL database in unconventional ways.Check out Arup's work! ➡️ arupchak.comGet Tern Stories in your inbox: ➡️ https://tern.sh/youtube

In this episode of Turn Stories, I dive deep into my experiences with Bobby Grayson, the first engineer at Quantierra, a YC-backed startup.Bobby shares his journey from the chaos of WeWork to the unique challenges of a small startup, where he faced a messy codebase and low reliability. We discuss the impressive app he helped build, which aggregates vast amounts of data from New York City, and how he transformed the system to better support users' workflows.If you're curious about the intersection of technology and real estate, or if you're an engineer looking for inspiration on tackling complex projects, this episode is a must-listen. Join us as we explore the future of software development and the exciting possibilities that lie ahead.Connect with Bobby! ➡️ https://bsky.app/profile/bobbby.onlineGet Tern Stories in your inbox! ➡️  https://tern.sh/youtube

In this episode, Cooper Bethea, a senior staff engineer at Slack, shares his journey of transforming Slack's architecture to a cellular model, allowing for more resilient operations.Cooper recounts the frustrations of dealing with outages and the decision-making process that led to the migration to a cellular architecture. He explains how the initial struggles with service discovery and load balancing prompted a reevaluation of their infrastructure.The key insight was that draining an AZ should not be a rare, high-stakes event but rather a routine operation that could be executed with confidence. Cooper discusses the importance of incremental changes and how they were able to practice draining traffic from AZs during peaceful times, ultimately leading to a more robust system.This episode is a must-listen for anyone interested in infrastructure, reliability, and the challenges of scaling systems in a cloud environment.-----Get Tern Stories in your inbox: https://tern.sh/youtubeConnect with Cooper ➡️ https://www.linkedin.com/in/cooper-bethea-521936201/

In this episode of Tern Stories, I spoke with Maude Lemaire about a migration that started with SQL and ended with people taking shifts at dawn.  She joined Slack less than two years out of college, and within months, she was leading a core part of the company’s efforts to keep up with their biggest customer, IBM. The project: unifying Slack’s channel membership model—one of the most central, performance-sensitive parts of the product.At one point, the system was so fragile that engineers had to be in the office at 6 A.M. every day, just to watch IBM’s login spike and make sure the system didn’t collapse.  -----  Go check out what Maude does! ➡️ https://maudethecodetoad.com/  Her book, Refactoring at Scale, is available now 📖: https://www.oreilly.com/library/view/refactoring-at-scale/9781492075523/  Get Tern Stories in your inbox: https://tern.sh/youtube 

If you’ve worked on more than one code migration, you already know the punchline: none of them are the same.  Sure, it sounds like a React 17 → 18 upgrade should follow the same plan for everyone.   But a real-world code migration always find a way to be uniquely painful. Your app uses different corners of the library.  Your plugin stack has its own fingerprint.  Your engineers wrote some “just for now” code that’s still running five years later.  Whatever you thought the code migration would be, it won’t be.  This was one of the biggest takeaways in a recent episode of Tern Stories, where we looked inward for once.  My cofounder Ryan and I talked through what we’ve seen in our own migrations and the ones we’ve supported across companies.  Despite the variety, a few consistent truths emerged.---Get Tern Stories in your inbox: https://tern.sh/youtube

Alright, picture this. It's March 2020. Everybody just went to work from home. You work at Slack, which is suddenly one of three applications keeping the entire business world connected.  And nobody owns Memcache.  Today's episode of Turn Stories is with Glen Sanford, who decided he was going to own Memcache and he was going to migrate it.  I am stretching that word today.  Whether you're an aspiring engineer or a seasoned professional, Glen's insights will inspire you to take ownership of your projects and strive for continuous improvement!

In this episode of Turn Stories, I sit down with Anthony Sottile, who led Lyft's migration from Python 2 to 3.  They did 150 services in less than six months. But what stood out wasn't just the scale or the timeline, it was the approach.  They really leaned on tooling so they could ratchet progress forward, and then they'd lock it in with CI rules so nothing backslid.  They would ship automated PRs, and if nobody complained but nobody looked at them, they would just purge them, and they trusted their infrastructure.  They would do deployments where even if there were errors, they knew the system would retry, and there wouldn't be any user visible impact.  And that made for a really powerful migration story. So we talk about what worked, we talk about what didn't, and some of the most hilarious failures across a couple of key services.  -----  Get Tern Stories in your inbox: https://tern.sh/youtube  Go subscribe to Anthony! ➡️ https://www.youtube.com/anthonywritescode

“If I could wipe out one technology? TCP/IP.”   That was Mike Jervis’ answer. He was half-joking. Sort of.   Mike’s a cybersecurity and privacy lawyer at Mullen Coughlin. He works with companies after the worst has happened—when ransomware locks down production, customer data is exfiltrated, and legal deadlines start ticking. His job is to figure out what broke, what the law demands, and how to respond.  This episode of Tern Stories is about the aftermath of a breach. What’s surprising isn’t just the chaos—it’s how much of the outcome hinges on infrastructure, habits, and technical decisions made months or years before the incident.  Get Tern Stories in your inbox: https://tern.sh/youtube

What does it take to replace the core data store at a company like Datadog? That's the question I asked Ian Noland, who led Datadog's migration from Elasticsearch to a new system called Husky.  In this insightful conversation, Ian shares the challenges and triumphs of this monumental task, including why APM was the first product to move, how they used Kafka to run both systems in parallel, and the importance of deliberately preserving a system's bugs.  Join us as we delve into the world of observability and data management, and discover how Ian and his team successfully navigated this challenging journey.  Get Tern Stories in your inbox: https://tern.sh/youtube

When Postgres 11 approached end-of-life, a major travel company brought in site reliability engineer Ninad Pundalik to lead the upgrade. The setup: multiple Ruby on Rails apps, with multiple Postgres 11 instances on AWS RDS. No in-house infra team.  No clear ownership. Some tables still in use, others long forgotten.  Despite the uncertainty, the migration went smoothly. The team cut over cleanly, avoided downtime, and ended up with a simpler, more reliable setup than they started with.  Get Tern Stories in your inbox: https://tern.sh/youtube

Hal Anil, Staff Engineer at Braze, joined just as the company hit a turning point: KnockOutJS and CoffeeScript were no longer cutting it. In this episode of Tern Stories, Hal walks through how they migrated to React and TypeScript—without pausing product work or losing developer trust.We talk about: • Why they started with workshops, not code • How a single collapsible UI unlocked momentum • The real value of tooling (hint: it’s not automation) • Making migrations feel safe, even exciting

Yesterday, I got the chance to talk with Matt Ouille about their code migration of a critical internal service, their service catalog, and how they moved it from a struggling Python monolith to an event-driven architecture.   This code migration journey was not just a technical challenge; it was a transformative experience that turned reluctant stakeholders into enthusiastic champions of change.   If you've ever felt trapped by tech debt or wondered how real-world teams overcome messy scaling problems, this episode is for you.  Get Tern Stories in your inbox: https://tern.sh/youtube