Every developer has that folder. The one called or that you copy from repo to repo. You paste it in, spend twenty minute

Every developer has that folder. The one called utils or helpers that you copy from repo to repo. You paste it in, spend twenty minutes deleting references to old database schemas, ripping out auth checks that don’t apply, and renaming variables so your new linter stops screaming. I used to do this with a theming system I’d built, the Dynamic Theme Kit. It started as a feature inside one application, and for months, I treated it like a portable tool. I was wrong. Copying code is not reuse. It is duplication with extra steps.

The Trap of the Single-Project Mindset

When you build a feature inside a project, you make hundreds of invisible assumptions. The color palette might assume a certain CSS-in-JS setup. The spacing scale might reference a design token from your company’s brand guide. The toggle between light and dark mode might call a user preference endpoint unique to that app’s backend. These dependencies feel harmless because inside the project, they are harmless. They belong there.

The problem starts when you try to lift that code out. You discover that the “reusable” component is actually a web of hidden strings connecting it to that one codebase. I learned this with DTK. It generated theme variables, yes. But it also expected a specific folder structure. It imported a type definition from somewhere deep in the original app’s types directory. It assumed the presence of a global config object that only existed in that one repository. I had never noticed because within that project, everything was always present.

Turning DTK into a standalone package meant surgery, not expansion. I did not need more features. I needed fewer connections.

Extracting the Dynamic Theme Kit

The hardest work was sitting down with the codebase and asking, for every function and every export: does this serve the theming logic, or does it serve the project? I stripped out styling presets. I removed the assumption that the consumer would be a React application. I deleted the default color palettes entirely. The original project had a navy-and-slate corporate aesthetic baked into the defaults. That had to go. A package cannot ship your brand colors.

The new kit would do exactly one thing. It takes a configuration object—some color values, some spacing numbers, some typography scales—and it generates CSS custom properties. That is it. It does not apply them. It does not decide where they go in your DOM. It does not care if you use Tailwind, Styled Components, or plain HTML. It gives your application the variables, and your project chooses how to use them.

That constraint felt limiting at first. It turned out to be liberating.

What Breaks When You Actually Try to Reuse It

Before I published anything, I needed proof that the abstraction actually held water. I pulled three small personal projects out of my archive: a markdown preview tool, a habit tracker, and a landing page for an event. None of them shared a framework or a folder structure. I installed DTK locally in each one and tried to theme them.

The first attempt failed immediately. The variable names DTK generated were too specific. It was outputting tokens like --primary-action and --background-overlay that implied a certain UI layout. In the markdown previewer, those names made no sense. There was no action button. There was no overlay. I renamed the generation logic to produce neutral, structural names that described the value rather than the widget.

I also found that my default values were too aggressive. When a user passed an incomplete config, DTK would fill in gaps with values that looked fine in a dense dashboard but broke on a sparse landing page. I switched to transparent defaults where missing tokens simply did not render, letting the consuming project define its own fallbacks.

Then there was the documentation. What seemed obvious to me—"just pass a config object"—was vague to someone reading the README at midnight. I rewrote it with real objects, real file paths, and clear explanations of what happens when you call the function versus what your application needs to do after.

These small personal projects acted as test beds. They were low stakes, but they exposed real flaws I would not have caught by staring at the source code in isolation.

The Real Test: Production at Web Weavers World

Miradi binafsi ni maeneo ya majaribio (sandboxes). Haina tarehe za mwisho, wadau, wala CSS ya zamani iliyokuwepo kabla ya kifurushi chako. Jaribio halisi lilikuja nilipounganisha DTK kwenye Web Weavers World, tovuti yangu ya biashara. Hii ilikuwa tovuti inayotumika (live property) yenye mitindo iliyopo, matarajio ya mteja, na uchambuzi (analytics) wa kuzingatia. Ikiwa kifurushi kingeharibu kitu, nisingeweza tu kufuta repo na kuanza upya.

Niliiongeza DTK kwenye build pipeline, nikaielekeza kwenye mpangilio mpya wa rangi, na kuiruhusu itengeneze seti mpya ya CSS variables. Kuunganisha huku kulichukua mchana mmoja, si wiki nzima. Hiyo ilikuwa ishara. Hapo awali, kuongeza mandhari (theme) mpya kulimaanisha kuandika CSS mpya, kutafuta thamani za hex zilizowekwa moja kwa moja (hardcoded) kwenye faili ishirini, na kutumaini kuwa sikupitwa na hali fulani ya kipekee (edge case). Sasa ninaongeza paleti kwenye faili la mpangilio (configuration file), DTK inatengeneza variables, na sehemu nyingine ya tovuti inazitumia. Mantiki ya mandhari (theme logic) ilibadilika kutoka kuwa mchakato mwepesi wa kumanual hadi kitu ninachokiamini vya kutosha kukikabidhi kwa washiriki wenzangu.

Maswali Matatu Yaliyobadilisha Jinsi Ninavyojenga

Kupitia mchakato huu ilinilazimu kuweka orodha ya mambo ya kuzingatia (mental checklist) ambayo sasa ninaitumia kabla ya kufanya uabstrakti (abstract) kwa kitu chochote:

• Je, variable hii ni ya jumla kweli? Ikiwa jina au mantiki inarejelea dhana ya uwanja (domain concept) kutoka kwenye mradi wa awali, inabaki nyuma.
• Je, hii inapaswa kuwa kwenye kifurushi (package) au kwenye programu (application)? Sheria za biashara, utambulisho wa chapa, na dhana za mpangilio (layout assumptions) huishi kwenye programu. Mifumo ya msingi (plumbing) inayotengeneza matokeo yaliyosanifishwa huishi kwenye kifurushi.
• Je, ninatatua tatizo linaloweza kutumika tena au tatizo la mradi mahususi? Hili ndilo gumu zaidi kujibu kwa uaminifu. Tunapenda kufikiri kuwa suluhisho zetu ni za ulimwengu mzima. Mara nyingi ni za mahali fulani tu.

Kujibu maswali haya ilinilazimu kurahisisha usanifu wangu, mara nyingi kwa kuondoa kodi badala ya kuiongeza. DTK ilinifundisha kuwa kutumia tena (reuse) si zawadi unayojipa mwenyewe. Ni nidhamu unayoifanya kwa kukataa urahisi wa muda mfupi.

Njia Tofauti ya Kufikiria Kuhusu Refactoring

Nilikuwa nikipima marekebisho (refactors) kwa jinsi ilivyofanya kodi kuwa fupi zaidi. Mistari michache ilionekana kama maendeleo. Sasa ninazipima kwa jinsi zinavyofungua milango mingi. Dynamic Theme Kit si ya kuvutia kwa sababu ni fupi. Ni muhimu kwa sababu imevumilia miradi mitatu binafsi isiyohusiana na tovuti ya biashara inayotumika bila kuhitaji kubadilisha sehemu zake za ndani.

Hiyo ndiyo kipimo kinachojali. Kodi inayofanya kazi mara moja ni gharama. Kodi inayofanya kazi mara kwa mara ni rasilimali. Kabla ya kuanza kipengele (feature) chochote sasa, ninasimama. Najiuliza ikiwa ninajenga kitu nitakachohitaji tena. Ikiwa jibu ni ndiyo, ninakijenga tofauti tangu mstari wa kwanza. Ninatenga viingizio (inputs). Ninatafuta matokeo (outputs). Ninaondoa dhana (assumptions).

Refactoring bora haifanyi kodi yako kuwa fupi. Inafanya kodi yako ifanye kazi katika maeneo ambayo bado hujaweza kuyawazia.