Tern
@tern.sh
AI code migrations, because it shouldn't have to be so much work. https://tern.sh
AI doesn't just write better code with good abstractions, it writes dramatically better code.
Apollo's CEO on why concise, well-structured code is now a competitive advantage.
www.youtube.com/watch?v=Z0Ce...
Apollo's CEO on why concise, well-structured code is now a competitive advantage.
www.youtube.com/watch?v=Z0Ce...
November 4, 2025 at 10:03 PM
AI doesn't just write better code with good abstractions, it writes dramatically better code.
Apollo's CEO on why concise, well-structured code is now a competitive advantage.
www.youtube.com/watch?v=Z0Ce...
Apollo's CEO on why concise, well-structured code is now a competitive advantage.
www.youtube.com/watch?v=Z0Ce...
Your hotel reservation system is from 1987 and it's never going away.
Apollo's CEO on why enterprise silos are a feature, not a bug—and what that means for building with AI.
www.youtube.com/watch?v=Z0Ce...
Apollo's CEO on why enterprise silos are a feature, not a bug—and what that means for building with AI.
www.youtube.com/watch?v=Z0Ce...
November 3, 2025 at 8:44 PM
Your hotel reservation system is from 1987 and it's never going away.
Apollo's CEO on why enterprise silos are a feature, not a bug—and what that means for building with AI.
www.youtube.com/watch?v=Z0Ce...
Apollo's CEO on why enterprise silos are a feature, not a bug—and what that means for building with AI.
www.youtube.com/watch?v=Z0Ce...
AI code generation only works if you know what you want it to build.
Apollo's CEO on why systems thinking is the new bottleneck, not coding speed.
www.youtube.com/watch?v=Z0Ce...
Apollo's CEO on why systems thinking is the new bottleneck, not coding speed.
www.youtube.com/watch?v=Z0Ce...
November 1, 2025 at 2:19 PM
AI code generation only works if you know what you want it to build.
Apollo's CEO on why systems thinking is the new bottleneck, not coding speed.
www.youtube.com/watch?v=Z0Ce...
Apollo's CEO on why systems thinking is the new bottleneck, not coding speed.
www.youtube.com/watch?v=Z0Ce...
GraphQL isn't REST's competitor. It's SQL for your APIs.
Apollo's CEO explains why this matters more than you think.
www.youtube.com/watch?v=Z0Ce...
Apollo's CEO explains why this matters more than you think.
www.youtube.com/watch?v=Z0Ce...
October 30, 2025 at 10:03 PM
GraphQL isn't REST's competitor. It's SQL for your APIs.
Apollo's CEO explains why this matters more than you think.
www.youtube.com/watch?v=Z0Ce...
Apollo's CEO explains why this matters more than you think.
www.youtube.com/watch?v=Z0Ce...
At Snap, tool adoption wasn't mandated. It was inevitable.
Ben Hollis built infrastructure with loose coupling + declarative config. Teams could work without coordinating.
Design for the org structure you have, not the one you wish you had.
www.youtube.com/watch?v=5zJ5...
Ben Hollis built infrastructure with loose coupling + declarative config. Teams could work without coordinating.
Design for the org structure you have, not the one you wish you had.
www.youtube.com/watch?v=5zJ5...
October 28, 2025 at 9:04 PM
At Snap, tool adoption wasn't mandated. It was inevitable.
Ben Hollis built infrastructure with loose coupling + declarative config. Teams could work without coordinating.
Design for the org structure you have, not the one you wish you had.
www.youtube.com/watch?v=5zJ5...
Ben Hollis built infrastructure with loose coupling + declarative config. Teams could work without coordinating.
Design for the org structure you have, not the one you wish you had.
www.youtube.com/watch?v=5zJ5...
Snap killed payments in 2016.
In 2018, they had to support it again. Why? Saved messages.
"How do you even get one of those? You have to go find one."
Every quick experiment becomes archaeology later.
www.youtube.com/watch?v=5zJ5...
In 2018, they had to support it again. Why? Saved messages.
"How do you even get one of those? You have to go find one."
Every quick experiment becomes archaeology later.
www.youtube.com/watch?v=5zJ5...
October 27, 2025 at 4:12 PM
Snap killed payments in 2016.
In 2018, they had to support it again. Why? Saved messages.
"How do you even get one of those? You have to go find one."
Every quick experiment becomes archaeology later.
www.youtube.com/watch?v=5zJ5...
In 2018, they had to support it again. Why? Saved messages.
"How do you even get one of those? You have to go find one."
Every quick experiment becomes archaeology later.
www.youtube.com/watch?v=5zJ5...
Snap's CEO: redesign the app in 30 days.
They shipped on time. User growth went negative.
The problem: monolithic infrastructure couldn't support iteration. Big bang launch, no adjustments.
You can't throw people at system constraints.
www.youtube.com/watch?v=5zJ5...
They shipped on time. User growth went negative.
The problem: monolithic infrastructure couldn't support iteration. Big bang launch, no adjustments.
You can't throw people at system constraints.
www.youtube.com/watch?v=5zJ5...
October 25, 2025 at 2:18 PM
Snap's CEO: redesign the app in 30 days.
They shipped on time. User growth went negative.
The problem: monolithic infrastructure couldn't support iteration. Big bang launch, no adjustments.
You can't throw people at system constraints.
www.youtube.com/watch?v=5zJ5...
They shipped on time. User growth went negative.
The problem: monolithic infrastructure couldn't support iteration. Big bang launch, no adjustments.
You can't throw people at system constraints.
www.youtube.com/watch?v=5zJ5...
Snap rewrote infrastructure while bleeding users.
Why? They weren't trying to drive growth—they were trying to ship features in days instead of quarters.
18 months later: 500M DAU.
Migrations enable growth, don't drive it.
www.youtube.com/watch?v=5zJ5...
Why? They weren't trying to drive growth—they were trying to ship features in days instead of quarters.
18 months later: 500M DAU.
Migrations enable growth, don't drive it.
www.youtube.com/watch?v=5zJ5...
October 23, 2025 at 10:03 PM
Snap rewrote infrastructure while bleeding users.
Why? They weren't trying to drive growth—they were trying to ship features in days instead of quarters.
18 months later: 500M DAU.
Migrations enable growth, don't drive it.
www.youtube.com/watch?v=5zJ5...
Why? They weren't trying to drive growth—they were trying to ship features in days instead of quarters.
18 months later: 500M DAU.
Migrations enable growth, don't drive it.
www.youtube.com/watch?v=5zJ5...
"An API that can't be used by an agent is probably not that valuable."
Apollo CEO Matt DeBergalis on why the AI race is about surface area, not sophistication.
The companies winning aren't talking about it. Here's why: youtu.be/Z0Ceg4uEXmY
Apollo CEO Matt DeBergalis on why the AI race is about surface area, not sophistication.
The companies winning aren't talking about it. Here's why: youtu.be/Z0Ceg4uEXmY
October 13, 2025 at 4:48 PM
"An API that can't be used by an agent is probably not that valuable."
Apollo CEO Matt DeBergalis on why the AI race is about surface area, not sophistication.
The companies winning aren't talking about it. Here's why: youtu.be/Z0Ceg4uEXmY
Apollo CEO Matt DeBergalis on why the AI race is about surface area, not sophistication.
The companies winning aren't talking about it. Here's why: youtu.be/Z0Ceg4uEXmY
Real velocity isn’t “we shipped.”
It’s “we shipped and trust never flickered.”
How Sourcegraph added AND/OR/NOT while guarding the highest-risk path.
www.youtube.com/watch?v=kd4y...
It’s “we shipped and trust never flickered.”
How Sourcegraph added AND/OR/NOT while guarding the highest-risk path.
www.youtube.com/watch?v=kd4y...
October 1, 2025 at 4:09 PM
Real velocity isn’t “we shipped.”
It’s “we shipped and trust never flickered.”
How Sourcegraph added AND/OR/NOT while guarding the highest-risk path.
www.youtube.com/watch?v=kd4y...
It’s “we shipped and trust never flickered.”
How Sourcegraph added AND/OR/NOT while guarding the highest-risk path.
www.youtube.com/watch?v=kd4y...
Users saw “AND/OR/NOT.”
They didn’t see the scaffolding that made it safe.
Unglamorous engineering—parsers, ranking, caching, telemetry—so the UI stays calm.
www.youtube.com/watch?v=kd4y...
They didn’t see the scaffolding that made it safe.
Unglamorous engineering—parsers, ranking, caching, telemetry—so the UI stays calm.
www.youtube.com/watch?v=kd4y...
September 27, 2025 at 2:18 PM
Users saw “AND/OR/NOT.”
They didn’t see the scaffolding that made it safe.
Unglamorous engineering—parsers, ranking, caching, telemetry—so the UI stays calm.
www.youtube.com/watch?v=kd4y...
They didn’t see the scaffolding that made it safe.
Unglamorous engineering—parsers, ranking, caching, telemetry—so the UI stays calm.
www.youtube.com/watch?v=kd4y...
Confidence is a deliverable.
Reference impl → grammar-guided fuzzing → differential tests.
Same inputs through old+new; investigate every delta. High-risk change, low-drama release.
www.youtube.com/watch?v=kd4y...
Reference impl → grammar-guided fuzzing → differential tests.
Same inputs through old+new; investigate every delta. High-risk change, low-drama release.
www.youtube.com/watch?v=kd4y...
September 24, 2025 at 4:12 PM
Confidence is a deliverable.
Reference impl → grammar-guided fuzzing → differential tests.
Same inputs through old+new; investigate every delta. High-risk change, low-drama release.
www.youtube.com/watch?v=kd4y...
Reference impl → grammar-guided fuzzing → differential tests.
Same inputs through old+new; investigate every delta. High-risk change, low-drama release.
www.youtube.com/watch?v=kd4y...
New features get launch teams.
Who protects the core?
Treat “don’t break the core” as a deliverable: owners, golden tests, shadow compares, clear gates.
www.youtube.com/watch?v=kd4y...
Who protects the core?
Treat “don’t break the core” as a deliverable: owners, golden tests, shadow compares, clear gates.
www.youtube.com/watch?v=kd4y...
September 16, 2025 at 9:03 PM
New features get launch teams.
Who protects the core?
Treat “don’t break the core” as a deliverable: owners, golden tests, shadow compares, clear gates.
www.youtube.com/watch?v=kd4y...
Who protects the core?
Treat “don’t break the core” as a deliverable: owners, golden tests, shadow compares, clear gates.
www.youtube.com/watch?v=kd4y...
Sourcegraph's parser handled millions of queries daily. Rijnard had to rewrite it without anyone noticing. His decision framework: "timeline and vibes."
0 bugs.
Full episode → youtu.be/kd4yYjc6LrE
0 bugs.
Full episode → youtu.be/kd4yYjc6LrE
September 15, 2025 at 7:26 PM
Sourcegraph's parser handled millions of queries daily. Rijnard had to rewrite it without anyone noticing. His decision framework: "timeline and vibes."
0 bugs.
Full episode → youtu.be/kd4yYjc6LrE
0 bugs.
Full episode → youtu.be/kd4yYjc6LrE
Migrations aren’t hard because the code is hard.
They’re hard because teams only discover what to do once they’ve already started.
AI won’t do the migration for you. But it can help teams learn earlier, together. That moves the needle.
🎥 Full episode: www.youtube.com/watch?v=xzjm...
They’re hard because teams only discover what to do once they’ve already started.
AI won’t do the migration for you. But it can help teams learn earlier, together. That moves the needle.
🎥 Full episode: www.youtube.com/watch?v=xzjm...
September 13, 2025 at 2:19 PM
Migrations aren’t hard because the code is hard.
They’re hard because teams only discover what to do once they’ve already started.
AI won’t do the migration for you. But it can help teams learn earlier, together. That moves the needle.
🎥 Full episode: www.youtube.com/watch?v=xzjm...
They’re hard because teams only discover what to do once they’ve already started.
AI won’t do the migration for you. But it can help teams learn earlier, together. That moves the needle.
🎥 Full episode: www.youtube.com/watch?v=xzjm...
Stripe shipped Flow→TS with 33,000 @ts-expect-errors.
Not reckless. They made problems explicit so the team could move forward.
Migrations don’t need perfection. They need visibility.
AI can help pull those surprises forward.
🎥 Full episode: www.youtube.com/watch?v=xzjm...
Not reckless. They made problems explicit so the team could move forward.
Migrations don’t need perfection. They need visibility.
AI can help pull those surprises forward.
🎥 Full episode: www.youtube.com/watch?v=xzjm...
September 10, 2025 at 4:08 PM
Stripe shipped Flow→TS with 33,000 @ts-expect-errors.
Not reckless. They made problems explicit so the team could move forward.
Migrations don’t need perfection. They need visibility.
AI can help pull those surprises forward.
🎥 Full episode: www.youtube.com/watch?v=xzjm...
Not reckless. They made problems explicit so the team could move forward.
Migrations don’t need perfection. They need visibility.
AI can help pull those surprises forward.
🎥 Full episode: www.youtube.com/watch?v=xzjm...
Twitter’s “Twitpocalypse” wasn’t really about databases.
The ALTER TABLE was trivial.
The real bottleneck was communication. Sharing surprises fast across thousands of customers.
AI solves this. Or at least help, hugely.
🎥 Full episode: www.youtube.com/watch?v=xzjm...
The ALTER TABLE was trivial.
The real bottleneck was communication. Sharing surprises fast across thousands of customers.
AI solves this. Or at least help, hugely.
🎥 Full episode: www.youtube.com/watch?v=xzjm...
September 4, 2025 at 10:04 PM
Twitter’s “Twitpocalypse” wasn’t really about databases.
The ALTER TABLE was trivial.
The real bottleneck was communication. Sharing surprises fast across thousands of customers.
AI solves this. Or at least help, hugely.
🎥 Full episode: www.youtube.com/watch?v=xzjm...
The ALTER TABLE was trivial.
The real bottleneck was communication. Sharing surprises fast across thousands of customers.
AI solves this. Or at least help, hugely.
🎥 Full episode: www.youtube.com/watch?v=xzjm...
AI’s real migration unlock isn’t codegen.
It’s helping teams learn faster.
From Stripe→TS to Twitter’s Twitpocalypse to Slack’s GovSlack, the same 3 lessons repeat:
1. Research upfront
2. Share mid-stream
3. Spot the long pole
🎥 youtu.be/xzjmlRKLuQM
It’s helping teams learn faster.
From Stripe→TS to Twitter’s Twitpocalypse to Slack’s GovSlack, the same 3 lessons repeat:
1. Research upfront
2. Share mid-stream
3. Spot the long pole
🎥 youtu.be/xzjmlRKLuQM
September 2, 2025 at 1:53 PM
AI’s real migration unlock isn’t codegen.
It’s helping teams learn faster.
From Stripe→TS to Twitter’s Twitpocalypse to Slack’s GovSlack, the same 3 lessons repeat:
1. Research upfront
2. Share mid-stream
3. Spot the long pole
🎥 youtu.be/xzjmlRKLuQM
It’s helping teams learn faster.
From Stripe→TS to Twitter’s Twitpocalypse to Slack’s GovSlack, the same 3 lessons repeat:
1. Research upfront
2. Share mid-stream
3. Spot the long pole
🎥 youtu.be/xzjmlRKLuQM
Twitpocalypse 2: Nothing supported 64-bit integers in 2010.
Java? No unsigned type.
Ruby MySQL? Broken.
JavaScript? Stores them as floats.
But this time when Twitter said "urgent," everyone believed them.
→ www.youtube.com/watch?v=gfsw...
Java? No unsigned type.
Ruby MySQL? Broken.
JavaScript? Stores them as floats.
But this time when Twitter said "urgent," everyone believed them.
→ www.youtube.com/watch?v=gfsw...
August 30, 2025 at 2:18 PM
Twitpocalypse 2: Nothing supported 64-bit integers in 2010.
Java? No unsigned type.
Ruby MySQL? Broken.
JavaScript? Stores them as floats.
But this time when Twitter said "urgent," everyone believed them.
→ www.youtube.com/watch?v=gfsw...
Java? No unsigned type.
Ruby MySQL? Broken.
JavaScript? Stores them as floats.
But this time when Twitter said "urgent," everyone believed them.
→ www.youtube.com/watch?v=gfsw...
Twitter had 6 weeks before running out of tweet IDs. The fix took 1 hour.
They spent 4.5 weeks on it.
Why? Every mobile app was third-party in 2009. Break their assumptions, break Twitter.
Sometimes coordination IS the engineering.
→ www.youtube.com/watch?v=gfsw...
They spent 4.5 weeks on it.
Why? Every mobile app was third-party in 2009. Break their assumptions, break Twitter.
Sometimes coordination IS the engineering.
→ www.youtube.com/watch?v=gfsw...
August 27, 2025 at 4:06 PM
Twitter had 6 weeks before running out of tweet IDs. The fix took 1 hour.
They spent 4.5 weeks on it.
Why? Every mobile app was third-party in 2009. Break their assumptions, break Twitter.
Sometimes coordination IS the engineering.
→ www.youtube.com/watch?v=gfsw...
They spent 4.5 weeks on it.
Why? Every mobile app was third-party in 2009. Break their assumptions, break Twitter.
Sometimes coordination IS the engineering.
→ www.youtube.com/watch?v=gfsw...
Twitter's hackiest fix was supposed to last 6 months.
It ran for 2 years.
By the end: new database partition every 2 weeks. DBA living at the datacenter.
Everyone hated it. It never broke.
→ www.youtube.com/watch?v=gfsw...
It ran for 2 years.
By the end: new database partition every 2 weeks. DBA living at the datacenter.
Everyone hated it. It never broke.
→ www.youtube.com/watch?v=gfsw...
August 23, 2025 at 2:19 PM
Twitter's hackiest fix was supposed to last 6 months.
It ran for 2 years.
By the end: new database partition every 2 weeks. DBA living at the datacenter.
Everyone hated it. It never broke.
→ www.youtube.com/watch?v=gfsw...
It ran for 2 years.
By the end: new database partition every 2 weeks. DBA living at the datacenter.
Everyone hated it. It never broke.
→ www.youtube.com/watch?v=gfsw...
8 months building the "right" solution with Cassandra. VP killed it.
Ryan's takeaway: bad→ok→awesome
You can't swim to the horizon when you're drowning. First get to shore.
→ www.youtube.com/watch?v=gfsw...
Ryan's takeaway: bad→ok→awesome
You can't swim to the horizon when you're drowning. First get to shore.
→ www.youtube.com/watch?v=gfsw...
August 20, 2025 at 4:06 PM
8 months building the "right" solution with Cassandra. VP killed it.
Ryan's takeaway: bad→ok→awesome
You can't swim to the horizon when you're drowning. First get to shore.
→ www.youtube.com/watch?v=gfsw...
Ryan's takeaway: bad→ok→awesome
You can't swim to the horizon when you're drowning. First get to shore.
→ www.youtube.com/watch?v=gfsw...
Six weeks to no new tweets. A three-week hack saved Twitter and ran for two years. Then came Snowflake .... and canceling a Cassandra rewrite.
Ryan King tells it: www.youtube.com/watch?v=gfsw...
Ryan King tells it: www.youtube.com/watch?v=gfsw...
August 19, 2025 at 12:38 PM
Six weeks to no new tweets. A three-week hack saved Twitter and ran for two years. Then came Snowflake .... and canceling a Cassandra rewrite.
Ryan King tells it: www.youtube.com/watch?v=gfsw...
Ryan King tells it: www.youtube.com/watch?v=gfsw...
Don’t query prod.
Snapshot → warehouse → alert.
Slack’s way to catch bad data early → youtu.be/HkgVceJN1fc
Snapshot → warehouse → alert.
Slack’s way to catch bad data early → youtu.be/HkgVceJN1fc
August 14, 2025 at 10:06 PM
Don’t query prod.
Snapshot → warehouse → alert.
Slack’s way to catch bad data early → youtu.be/HkgVceJN1fc
Snapshot → warehouse → alert.
Slack’s way to catch bad data early → youtu.be/HkgVceJN1fc
Hundreds of millions of users.
One source of truth.
How Slack killed n+1 user data → youtu.be/HkgVceJN1fc
One source of truth.
How Slack killed n+1 user data → youtu.be/HkgVceJN1fc
August 13, 2025 at 4:05 PM
Hundreds of millions of users.
One source of truth.
How Slack killed n+1 user data → youtu.be/HkgVceJN1fc
One source of truth.
How Slack killed n+1 user data → youtu.be/HkgVceJN1fc