Judgment Is a Skill — Personalis

Introduction

Judgment is a skill. It is learned and needs to be practised. Good decisions are not obvious when they are made; they take time and results to evaluate. Big decisions do not come along often. The combination of these facts makes developing good judgment difficult, but not impossible. You should start practising now.

Background

When I became a manager in 2024, I was promoted from a junior engineer position straight into managing a team of software engineers. There were engineers in that team with decades more experience than me, and now I needed to guide them. To make it more difficult, the team was formed out of two smaller groups and so we had not all worked together.

It felt like I was thrown in the deep end. I immediately needed to make decisions for the team, set priorities and communicate to management. This was incredibly uncomfortable; imposter syndrome was in full effect. I tried to overcome this anxiety by constantly looking for consensus within the team. All decisions became team votes and this slowed us down.

After six months, my manager surveyed the team on my performance, in preparation for my official transition. In general, the team was happy and we were performing well, but they gave consistent feedback. I was asking for too much input and not deciding for myself often enough. At first, I was happy about this critical feedback because I thought that it meant I had done the right thing and not disenfranchised the team. But I had overcorrected and hadn't given myself the opportunity to develop good judgment. So, I changed gears and with my official transition into management, I set myself the goal of developing and practising the skill.

What I Learned

Trust Is the Foundation

I did overcorrect, but I do believe that building a foundation of trust is the first step. Building trust can happen in many ways, as I describe later on, but the one direction that I did take from the beginning was acknowledging the experience and skill of my team members.

In my first 1:1s with them, I stated: 'You are here because you are a strong engineer and have the technical experience. For judgments of technical direction I will look to you to make the first suggestion.' This approach acknowledged their strength and knowledge and set the framing going forward.

As you build trust, you can move quicker. There is less need to check in and reach consensus, because team members can trust that you are making decisions with the correct amount of data and input from stakeholders.

Data and the Lack of It

Speaking of data, I like the idea of data-driven decisions, and you would have to search far and wide to find someone who doesn't. The problem is that data-driven is not a binary property. The amount of data available to you and the amount you use in the decision-making process can vary widely and for good reason. With this in mind, I have found the mental model of one-way and two-way doors to be a helpful framing.

Figure out whether the decision you are making is reversible. For example, starting the first production run of your product may use all your available capital and therefore it is an irreversible decision. Whereas, prototyping an idea using one of a couple of commoditised API services is highly reversible. Using the model, you can then aim to gain as much data as needed to understand whether it is a one-way or two-way door decision. If it is a two-way door decision, get 70% of the data you feel you need. In the case of a one-way door decision, break it down into two-way door decisions to decrease the overall risk.

Repetition and Feedback

Practising judgment requires making many decisions and having a good feedback loop to be effective. You can create a feedback loop by actively seeking feedback from stakeholders and defining which metrics you will use for evaluating success when you make the decision.

You cannot guarantee that feedback will be quick. Some decisions will take months to bear results and others in seconds. Each decision, no matter how big or small, should be used as a learning opportunity.

A high density of decisions compensates for slow per-decision feedback. The compensation is essential to ensure you are ready to make big decisions when they are required. They cannot be the only time you practise judgment.

The good news is that the lessons are broadly applicable. Did you not gather enough data, and so the decision was wrong? Did you have enough data but not communicate the decision well, leading to an incorrect implementation? Did you do everything correctly, but the dice just didn't fall your way? All of these outcomes will happen to you and more than once, so use them to make sure each time you are improving.

Practising Judgment

Commit Now

You will have already been practising judgment your whole life, but start with deliberate practice now. You need to get the reps in, which will mean that you need to make many decisions,...