Engineering a hoodie

Who said developers couldn’t sew

Randy Tolentino
7 min readDec 19, 2016


The peripheral necessities

Last summer, my wife bought me a sewing machine for my birthday. I’ve been asking for one after watching Youtube videos of people altering their personal gear for better fit. It wasn’t so much the actual clothing that I was into, but it was the ability and the know-how that truly grabbed my interest.

With my new machine, I began exploring how to taper my jeans. After screwing up a few pairs, I moved onto converting long-sleeve button ups into short-sleeves — that didn’t turn out so great either.

I quickly realized that there was one minor blocker — I knew nothing about sewing. Plus, learning how to sew properly would require more attention than I had time for.

So, I tucked it away on the highest shelf in my kids’ closet and acted like the whole thing never happened.

Learning to sew, for real

Recently, I felt inspired to learn something new, so instead of doing yet another code project, I decided to revisit that whole sewing thing again.

Maybe this time around would be different.

Appropriately, I retrieved my sewing machine from the shelf, gave it a little pep talk, and began reviewing its manual in more depth. I also watched videos of others working their own machines, just to see if I could pick up new techniques.

My customized Brother sewing machine

After reviewing the basics, I rethreaded from the top, loaded the quick-set bobbin, selected the stitch and thread tension accordingly, and began a few practice runs.

I practiced on and off in short sessions for about a week, until I reached a place where I knew exactly how some of the basic functionalities worked.

At some point, I was ready to reconsider taking on a real project.

Everyone needs a good hoodie

That’s the truth.

When imagining what to make in my first trial run of an actual project, I decided to make a hoodie! I really wanted to make a matching set for my wife and two boys, but figured that since I was still learning, I might as well use myself as the test run.

If there’s one thing I’ve become fairly good at over the past few years, it’d have to be ‘persevering through failure’. This happens every day, especially as a software developer, you try, you fail and you learn.

Sewing like a developer

In my mind, I felt like I could figure this out; after all, tackling this daunting task was no different from the kind of problem-solving methods I go through every day with writing code:

  • research the heck out of the problem or task at hand
  • generate ideas, develop an approach, and attempt to build
  • fail… many, many times
  • dust myself off and try again until I land at a solid solution

Design up front

During the initial brainstorming, I began to observe jackets, sweaters, and hoodies on people around me. I even went so far as to open up a Pinterest account, just to view various designs and patterns that other people shared.

For a couple of days, I’d spend my early mornings with a pencil in hand, sketching out ideas in a Moleskine journal that I keep at my desk. Eventually, I arrived at a design I liked: an extra long, all black, funnel-neck hoodie, with a few pops of teal.

After rounds of ideation

Inspect elements

For that entire week, I’d spend my lunch hours at JoAnn’s Fabric store, down the street from the IBM Design Studio. There, I’d feel and inspect different fabrics, take photos of their labels, examine their elasticities, then head back to work on an empty stomach.

Skipped a few lunches for fabric browsing at JoAnn’s

There were also many instances where I’d ask someone at work if I could take a closer look at their sweater or coat. I’d notice the cuts, the stitching, and try to imagine what technique or machine settings those styles required.

Reusable styles

In front-end development, I’ve learned to always look for functions, modules, styles, or components that have already been built, before writing something totally brand new. Also, since I didn’t want to work off of an official pattern, I decided to reuse style properties that I already had in my closet:

  • the width and length of the body was based off of the DigitalOcean & GitHub Hacktoberfest collab tee (since I love how that shirt fits).
Using my Hacktoberfest tee for length and width
  • the funnel-neck design was inspired by the profile of a Macy’s American Rag cowl-neck hoodie
Exaggerating a funnel-neck hood pattern
  • the sleeves would be based off of an H&M overlap hooded sweater
Chalked estimate based off of H&M overlap hoodie

Build the thing

Once I had all the components available, then came time to execute. First, I began with the hood piece, which wasn’t as difficult as I thought it would be.

Except… tiny issue — it didn’t fit correctly.

So, I quickly adjusted by creating an extra panel to extend the front of the funnel — still turned out pretty nice though. Actually, if it weren’t for this miscalculation, I wouldn’t have had a cleaner positioning for the grommets and hoodie strings.

The extended funnel panel gave way for clean grommet placements

Next, I worked on sewing the front and back pieces by joining the shoulders. This was extremely mindless and non-trivial — I’d size this task at a 2.

These Wonderclips are my jam right now

After the shoulders I moved onto attaching the sleeves (easy). Next was sewing on the hoodie piece (medium difficulty). Then I closed off the arms and down the side seams (super easy).

Reaching the halfway point

Next were the smaller details — I measured, pre-stitched, ironed, then sewed on the ribbed cuffs onto the sleeves (easy). Then onto the zipper pockets… man, the zippers.

Outlining the zipper pocket slots from the wrong-side of the fabric

The biggest mistake I made was saving the zipper pockets for the end. Cutting the slots and finalizing a clean top-stitch was very difficult, mainly because I had the entire sweater already sewn and there was just too much sweater to work around. Nonetheless, my seam-ripper helped out a ton, until I finally got it down correctly.

Top-stitching the zipper pocket detail

Testing locally

As each piece came together, I’d get overexcited and tested it out in the mirror. Similar to code, I’d test the functionality of each piece as it was sewn on, and didn’t proceed to the next step until I was 100% confident in its execution.

This process included:

  • careful up-close and far-away examination of the completed work
  • testing range of motion for that particular part of the hoodie
  • stepping out onto the patio to see if this dang thing even kept me warm

Debugging your mistakes

Oftentimes, during the testing phase, I’d discover a part that was crooked, a place where threads gathered incorrectly, or where the seams had a hole. This brings up a great point — get to know your seam ripper. This tiny but amazing tool can deconstruct your entire wardrobe; it is a must have.

Spent more time with this seam ripper than I did at the machine


After the discovery of each and every error, I’d take my time and undo all of my work, line by line. Sometimes, I’d walk away from the project for a few hours and reflect on the mistakes that I made. Then, I’d either plan a new execution or I’d research a modified approach. Once I had a better idea of what each particular step required, I headed back to the machine.

Ship to production

After about an honest week of work (~5 hours at the machine and ~8 hours with the seam ripper), I finally felt good enough to dark launch the project. Hence, I appropriately titled my first project the Dark Launch Hoodie.

It actually worked out perfectly since on the morning I decided to wear it, it was 39 degrees outside. The funnel-neck requirement had its first live production test and passed with ease — in other words, I was comfortably warm.

Shameless product shot in the IBM Watson bathroom

Several takeaways

If anyone is interested in taking on this sort of endeavor, I’d be more than happy to open source my ideas and experiences with learning to sew. For now, here are a few lessons learned that I think are worth sharing with whoever is interested:

  • purchase a seam ripper, I cannot emphasize this enough
  • use a real pair of fabric scissors, not the Office Depot kind that I use
  • if including zippers, handle them early in the process
  • be imaginative with your fabric and reuse as much as possible


Looking back, now that I have gone through the process, I have to admit that I am extremely pleased with even the basic skills I picked up. A few of the highlighted benefits include knowing how to fix, alter, and tailor clothing, along with having the ability to create something that is totally unique in comparison to anything else out there.

Next up, hoodies for the fam.




Randy Tolentino

Husband, dad, developer/designer. I write about inner growth, family, career, and selflessness. Feel free to find me at