Why (and How) I Conduct Personal Post-Mortems
Hey everyone, welcome to today's special feature! Today's post diverges from my usual technical tutorials to explore the personal side of software development.
Here’s what we’ll cover:
🔍 Why Personal Post-Mortems? — Understanding the reasons behind this reflective practice and introducing a custom template for analyzing decisions.
💡 Lessons & Example — Insights from my mistakes, their impact on my work, and a real-life example to illustrate these concepts.
🛠️ Applying the Lessons — How these insights can be used to improve both personal and professional growth.
Ready to dive into a different kind of learning? Let’s get started!
Personal Post Mortems
A couple of weeks ago, I made a decision that inadvertently kept over 20 people busy throughout the weekend. I did not make this decision lightly; I had solid reasons for choosing as I did, yet I still erred. Chances are, you have made a similar mistake at some point. The longer you work in software development, the higher the likelihood of making incorrect decisions—this is entirely normal and will even be beneficial since we often learn most from our mistakes.
The problem with my decision was a lack of second-order thinking. Looking back at other errors I've made, I see a similar pattern. So, did I learn anything from my previous mistakes? The answer is both yes and no. I gained more insight into the specific problem and adjacent areas, but I did not spend enough time contemplating the broader causes of my wrong decisions.
As is common with major incidents affecting multiple teams, we conducted an incident post-mortem. I am fortunate to work at a company that fosters a positive failure culture, so the post-mortem was blameless and focused on identifying improvements to help detect or avoid similar issues in the future. This discussion led to the learnings I mentioned earlier. However, I wanted to delve deeper into the underlying issues in my thinking and decision-making process, so I conducted a personal post-mortem. I was both the moderator and the sole participant, yet it turned out to be a lively discussion.
This incident prompted me to develop a more structured approach for dissecting such mistakes. Here's the post mortem template I created, designed to facilitate a thorough analysis and ensure we learn valuable lessons from each misstep.
The Template
0. TL;DR 🚨
Quick Summary: Summarize the key lesson or outcome in two sentences.
1. Decision Summary 📝
Description: Provide a brief description of the decision made.
Context: Explain the circumstances and rationale leading to the decision.
2. Expected vs. Actual Outcome 🎯➡️💥
Expected Outcome: Describe what you anticipated would happen as a result of the decision.
Actual Outcome: Detail what actually occurred and how it differed from expectations.
3. Analysis of Decision-Making Errors 🕵️♂️
Misjudgments: Identify specific errors in judgment or reasoning.
Information Gaps: Point out any overlooked or unavailable information that impacted the decision.
Bias and Influence: Reflect on any biases or external influences that might have affected your decision-making.
4. Key Lessons and Insights 📚
Fundamental Errors: Discuss the primary thinking errors or misconceptions that led to the mistake.
Preventative Measures: Describe steps or processes you can adopt to avoid similar mistakes in the future.
5. Action Plan 🚀
Improvements: List specific changes you will make in your decision-making or operational processes.
Monitoring: Outline how you will track the effectiveness of these improvements.
You see, this template is not much different from other templates. I did not add the common timeline of events as it does not add value in this case. This post-mortem is just for you. It is not used to explain to others what happened. You know what happened; you just want to reflect on what your personal part was that made it happen in the first place.
So be dead honest with yourself. Only this way will you get the most out of it.
Example for a Personal Post Mortem
Here is a filled out template. The incident described here is just an illustrative mix of everything I messed up in recent years:
0. TL;DR 🚨
Quick Summary: Failed to consider second-order effects in a seemingly simple decision to delete a server folder, leading to significant unplanned downtime. Reinforced the need for deeper verification and collaborative decision-making.
1. Decision Summary 📝
Description: I chose to delete a seemingly redundant folder from a remote server as part of a cleanup initiative to optimize server performance.
Context: This decision was not taken lightly; I believed I had solid reasons based on the current usage data and past cleanup outcomes.
2. Expected vs. Actual Outcome 🎯➡️💥
Expected Outcome: I anticipated this would streamline operations and reduce clutter and confusion without negative repercussions.
Actual Outcome: The decision inadvertently led to a critical application being halted due to the deletion of a deeply linked configuration file. This mistake kept my team busy for hours, trying to diagnose and fix the issue.
3. Analysis of Decision-Making Errors 🕵️♂️
Misjudgments: My primary error was a lack of second-order thinking. This involves going beyond the first-level consequences (e.g., cleaning up the server to improve performance) and considering the second-level consequences (e.g., how deleting a folder might impact other applications that might be indirectly using its contents). Had I engaged in second-order thinking, I would have anticipated the potential cascading effects of my decision, especially in a complex system with hidden dependencies like symlinks.
Information Gaps: Although I thought the folder was obsolete, I failed to verify this by checking deeper system linkages and dependencies. This oversight was due to focusing only on the immediate and obvious information (folder appears unused) without considering the broader system context (hidden links and critical dependencies).
Bias and Influence: Reflecting on this incident and others, I see a pattern of underestimating the complexity and interdependencies in system architecture. This oversight often comes from a bias towards action—wanting to solve perceived inefficiencies quickly without fully mapping out the potential repercussions.
4. Key Lessons and Insights 📚
Fundamental Errors: The key error was acting on assumptions without enough deep verification and consultation. This incident has reinforced the necessity of considering second-order effects in every significant decision.
Preventative Measures: To avoid similar mistakes, I need to enhance my decision-making process by incorporating steps for detailed impact analysis and actively seeking collaborative input before making unilateral decisions.
5. Action Plan 🚀
Improvements: I will implement a checklist that includes second-order thinking as a mandatory part of the decision-making process and establish a peer review mechanism for critical changes.
Monitoring: I plan to monitor the effectiveness of these measures by tracking future incidents and adjusting procedures as needed.
What now?
Facing our shortcomings is challenging but crucial for improvement. Here are three refined key takeaways:
Embrace Continuous Learning: Regularly revisiting decisions helps us identify and correct patterns in our thinking. This reflection is key not only for addressing past mistakes but also for enhancing future decision-making.
Implement Systematic Analysis: A structured approach to post-mortems allows for a deeper understanding of our actions. This method helps ensure that we grasp the reasons behind decisions, leading to more meaningful improvements.
Act on Improvements: Transform insights into specific, actionable steps. This conversion from insight to action systematically improves our decision-making skills, fostering better outcomes in professional settings.
By applying these practices regularly, we enhance our ability to learn from errors and strengthen our problem-solving skills, facilitating both personal growth and professional development.
Appreciate your time reading this! 🌟 If these insights resonated with you, don’t hesitate to comment 💬 and spread the word 🔄.