The defense

Yesterday I defended my master’s thesis. It went well. They said the words. I am, apparently, done.

I keep waiting to feel different.

Everyone tells me I must feel a great weight off my shoulders. I should be elated, or at least relieved. I should be ready to celebrate, or at least ready to stop worrying about it.

And I suppose in a way, I am. I am sleeping… better? I am sleeping heavier, not sure what that means.

The story behind the thing

I finished my master’s course in 2022, and had no thesis topic. And I had no thesis topic up until late 2024. No idea what to do. No inkling of a thought. No direction. My advisor one day said, “what about this?” and I said, “sure, that sounds good,” and then I spent two years on it. I wrote a lot of code, I ran a lot of experiments, I wrote a lot of words, and felt close to finishing at the end of 2025.

The closest I ever was to being done. My girlfriend had been pushing me to finish it for the prior two years. I had issues finding time, finding motivation. The topic is complex, and hard to get into. I explained to her that it took me about an hour to get into the right headspace to work on it, and that very often I just couldn’t bother.

First month of 2026, start of a new semester, I sent it over to my advisor. I thought to myself, “This is going to be the semester I finish this. This is going to be the semester I defend it and graduate.” After a couple very short rounds of feedback, I had a date for the defense. I had a date for the defense and a committee and a title and an abstract. And also, one last bit of feedback: “The paper’s great, but it’s too short, you sent me 16 pages, a master’s thesis is around 100. Check so-and-so’s thesis for structure, and as an example.”

What?

A journey of a hundred pages starts with a single… 16-page draft?

Turns out I had it all wrong, and I had written a scientific paper, instead of a master’s thesis. I went for so-and-so’s thesis, and it was 120 pages. Where the hell am I going to get 120 pages from?, I thought.

I inspected the sample thesis.

…

Wait a second.

The first 20 or so pages are not event content, a lot of them are blank pages, and the rest of them are appendices. About half the thesis, the tail-end, is mostly tables and graphs and captions and code snippets. So the actual content of this thesis is like 40 pages? Maybe? I can do that. I can write 40 pages. I already have about 16.

And I did, and I sent it over. Crisis averted. The defense was scheduled. I had a thesis. Not a paper.

The thing itself

The thesis was on shrinkage estimators for precision matrices inside ensemble Kalman filters — which is a sentence that means almost nothing to most people and a very specific thing to a few hundred. I’m not going to explain it here. I think I’ve explained it enough in the past 24 hours.

The prep

I took a “wild” guess that I had to dress formal for the defense. I took another “wild” guess that I had to prepare a talk. I was right on both counts, as my advisor called the night before and I sort of asked about it and he said, yes, definitely.

But that was the night before. 12 hours before. I had to make slides, and prepare a talk, and rehearse it in 12 hours.

Less than that if you account for being human and needing sleep.

The defense was at 8:00 AM. I went to sleep at 3:00AM.

I made a joke video for my friends’ group chat about removing the “Questions?” text in the last slide, implying I don’t want to be asked questions.

The room

The room felt cold, temperature-wise but also emotion-wise. I think because I was nervous. I arrived a couple of minutes early, and no one else was there. I took the time to get my bearings, set up my laptop, and try to calm down. I was still nervous when the committee arrived, but at least I wasn’t alone in the room.

Everyone there was someone I knew. They had been my professors at one point, even colleagues. They greeted me warmly and with a smile. Everyone was excited that after 4 years, I had my thesis and I was defending it. It was almost clear to me that the only person doubting me was me. That my nervousness was pretty much unfounded.

The talk

I treated the talk, the defense, the slide deck, like any other class I was teaching. Like any other monday or thursday in front of my students where I am talking to them about a topic, with my slides. I was clear on the content, had a structure in mind, was not afraid to go backwards and forwards on the deck either if I felt that it would help the topic be better understood.

And it was a success.

All comments were glowing, all questions I was able to answer, and even if I couldn’t answer one, or I faltered, my advisor was there, slightly behind the committee, throwing hand signs at me like a catcher behind home plate, trying to help me out. I was not alone in the room, and I felt that.

I felt supported, even though I suck at charades.

The verdict

They asked me to step out. I stood in a hallway for what was probably four minutes and felt like forty. When they called me back in, someone smiled before they spoke, which is how you know.

I shook hands. I was congratulated. I thanked them, and we all left the room for coffee and a chat, as peers.

After

I feel like the hardest part is over. The thing is done. The thing is defended. I am in the easy part now: paperwork for the actual graduation. I feel like I went from one pressure to another, and I can’t say for sure which is worse.

I have to do the paperwork in time to graduate this semester. Wouldn’t it suck to miss the deadline? I think that’s worse than not finishing your thesis for another semester. Like dropping out of a degree in the last week of the last semester.

I for sure can’t drop the ball. But it’s just a matter of asking questions, filling out forms, and getting signatures. It’s not like I have to write another 100 pages or do another experiment. It’s just a formality. But it’s a formality that has to be done right, done carefully.

What I’m taking with me

A handful of things, in no order:

• Most of the work was not the math. Most of the work was the tooling around the math — the pipelines, the plots, the sanity checks, the small scripts that quietly saved me weeks. (I am, apparently, the kind of person who builds tools. This is not news.)
• A result is only as trustworthy as the worst-tested step that produced it.
• “I don’t know, but here’s how I’d find out” is a complete answer.
• The people around you are there to help. They want you to succeed. They want you to do well. They want you to finish.

What’s next

The committee suggested I write a scientific paper about the thesis. My advisor was quick to mention that technically I already had one. I said I would have to make some adjustments, but it’s true. So I guess I am submitting a scientific paper as well.

They also suggested I expand on this work for a PhD. I don’t know if that’s in the cards for me, but it’s nice to know that the option is there, and that they think it’s worth pursuing.

One thing I definitely know is it is not in the cards for me in the near future. Maybe a couple of years down the line.