It is the evening of Sunday, and I've been haunted by my work project since Thursday.

QA messaged me that day, stating that a specific piece of software didn't work, and that they didn't see any obvious error. To my disappointment, I didn't see one either. The service just stopped processing the data - and it was my fault.

Before this obscure bug popped up, I'd had a perfectly productive week. For quite a while now, I have been working on improving the service and migrating it to the cloud. That process was moving along pretty well, and I was happy - until Thursday.

My failure to debug the problem resulted in my weekend being clouded by the anxiety of what's to come. I was dreading Monday.

Fixing bugs in this huge and complex software is exhausting. You never know what is really going on, so you have to reverse engineer old code and do a lot of guessing. I will need to spend hours or even days fixing something that shouldn't have been broken in the first place. In the end, I will just be restoring the normal operation of the service.

Realizing the scope of potential work, I got seriously upset. I was staring into the void and preparing to jump into it.

It took me some effort to recall a couple of basic truths that eventually cheered me up.

First of all, legacy code is unpredictable, and improving it is a lot of work. Tons of work. Secondly, even though I haven't experienced that many problems so far, projects like this are really slow. There is a lot of complexity and uncertainty involved, and that influences the development process.

My expectations, along with those of my colleagues and managers, don't always match reality. Usually, they are either naive or overly optimistic. Software estimations are mostly guesswork, so I shouldn't be too invested in them.

What I'm doing with this project is not easy. Therefore, the path to reaching the end goal will likely be turbulent. On Tuesday, I met the first major obstacle. More may be coming. But that doesn't mean that something is wrong.

I've come to terms with the possibility of tiring detours. Things will break and it will take a long time to understand why. Our plans won't be able to foresee the complexity of the work ahead. But that's okay.

It's as simple as it sounds. I just need to keep going, and I'll get there eventually. After all, nobody's pressuring me - it's just me against myself.