Why You Should Never Let Juniors Ship to Production Without Guardrails

This is a kind reminder to both web3 clients and beginner programmers. Let me stress this again: Never allow junior engineers to push changes to production without strict architectural review and deployment controls! Especially in fintech.

Here’s why.

I’ve been working with Unibrix, a team of autonomous, dedicated developers focused mainly on fintech and healthtech. Both industries require enterprise-grade security and ability to process massive volumes of data safely. They’ve done amazing work and even won awards for it.

In fact, what I like most about these guys (apart from knowing them personally and their passion for LEGO) is the courage to share their f*ck-ups, too. Everyone makes mistakes, but admitting them PLUS sharing them with others as lessons learned requires guts.

That’s their dynamic, non-formal culture, and I am happy to share this short story with you.

For one web3 project (can’t disclose details for ethical and NDA reasons), they received a technical specification and implemented it quickly — within a week. The client was happy and decided to publish a new crypto wallet as soon as possible. Users got excited and started sending money in and out. Business as usual.

However, one witty user decided to do a so-called penetration test. There happened to be a code vulnerability that allowed the withdrawal of more crypto than the user actually had, within a certain limit. (To be honest, I’d probably test the limits myself too if I found something like that. White-hacking without the “hacking.”)

So the guy managed to drain the wallet of about $70 grand before the automatic security systems triggered a warning and froze operations. The client alarmed Unibrix about the incident, and they quickly fixed the loophole.

On the surface, everything looked correct. The first mistake was skipping a proper architectural and security review. Because the wallet seemed simple, some requirements suggested the task could be delegated to junior developers.

That simplicity turned out to be deceptive.

The architecture should have been reviewed properly from the beginning — something they now require 100%, regardless of budget constraints.

The second mistake followed quickly. To accommodate the client’s budget, Unibrix agreed that “the client would test everything themselves.” In reality, that never took place. The client checked that the API returned the expected responses and deployed the system to production.

Then the inevitable happened.

Both the client and Unibrix team paid the price — financially and reputationally.

The lessons are painfully clear:

• Junior developers should not have the ability to push code to production.
• Architecture and security reviews are mandatory, not optional.
• “The client will test it” is unacceptable; even if the organization is capable and asks to do it on their own.
• Financial systems require zero-trust assumptions by default.

Guardrails, code reviews, and disciplined deployment processes cost far less than a single security incident. Every. Single. Time.

Would your team share their failures in order to get better?

Why You Should Never Let Juniors Ship to Production Without Guardrails was originally published in Coinmonks on Medium, where people are continuing the conversation by highlighting and responding to this story.