The unwritten rule of software engineering is simple: No deploys on Fridays.
It’s a rule written in blood, sweat, and lost weekends. We’ve all been there. You merge a “small fix” at 4:30 PM. The tests pass. The staging environment looks fine (because nobody has updated the data in staging since 2023). You push to production.
At 6:00 PM, your phone buzzes. PagerDuty. The “fix” broke the login flow for 5% of users.
Goodbye, weekend.
The “Works on My Machine” Problem at Scale
Why does this happen? It’s not because we are bad developers. It’s because our verification environments are flawed.
- Localhost is a lie: It doesn’t have the network latency, the weird data states, or the exact configuration of production.
- Staging is a ghost town: It’s often shared, meaning if Alice breaks staging, Bob can’t test his feature. Or the data is so stale it’s useless.
- CI is just a gate: Passing tests only prove that the code does what the tests expect, not what the user needs.
We rely on “hope” as a deployment strategy. We hope that the difference between our laptop and the Kubernetes cluster isn’t significant.
The Fly.io vs. The Fear
I’ve been looking at tools like Fly.io. They are fantastic at solving the deployment problem. They let you put your app close to your users, running on Firecracker microVMs. They solve the infrastructure headache.
But they don’t solve the confidence headache. Even if I can deploy to 20 regions in seconds, I’m still terrified if I’m deploying a bug to 20 regions in seconds.
We need a layer before the deploy. A layer that isn’t just a CI check, but a full, living replica of the application.
How PrevHQ Changes the Equation
This is where PrevHQ comes in.
Imagine this workflow:
- I write the code for the Friday fix.
- I open a PR.
- PrevHQ Bot instantly comments with a link:
https://pr-123.prevhq.app. - This isn’t a mock. It’s my app, running in a container, connected to a seeded database, accessible to the whole team.
I click the link. I log in. I try the flow myself. I send the link to the PM. “Hey, does this look right?” They click it on their phone. “Looks good.”
I didn’t just read the diff. I used the app.
Breaking the Friday Curse
Last Friday, I had a critical update. It was 4:15 PM.
In the past, I would have waited until Monday. But with PrevHQ, I had already been “running” this code in a preview environment for hours. I had clicked every button. I had verified the mobile layout. I knew, with certainty, that it worked.
I hit merge. The deploy pipeline ran.
And then? I went home. I had dinner. I slept.
The weekend was mine again.
PrevHQ isn’t just about preview URLs. It’s about reclaiming your confidence. It’s about making Friday just another day to ship value.