Monoliths, modular monoliths, and microservices
By the end of today you can say what problem microservices actually solve, name what they cost, and argue for a modular monolith without it sounding like an excuse.
YesterdayDays 59 to 64 gave you every distribution technique. Today asks how to divide the system that uses them.
TomorrowTomorrow you design a complete system end to end and defend every boundary you drew.
Why this matters
This is the most consequential and most fashion-driven decision in system design. Teams routinely take on distributed systems complexity to solve a problem they do not have.
- Monoliths
- Modular monoliths
- Microservices
- Drawing boundaries
Learn it
80 minCopy this into Claude or ChatGPT. It quizzes you before it explains anything, which is deliberate. The resources under it are how you check what it told you.
Today's Master Prompt
Free · sign inA prompt written for this day alone: your level, the exact scope, what to leave out, and an instruction to quiz you before it explains anything. Paste it into Claude or ChatGPT and it teaches you today's material.
Check it against something that is not a model
An assistant can be fluent and wrong, and on a topic you met today you will not catch it. These cover the same ground and were made by people who do this for a living, so they are what you hold the explanation up against. They are other people's work and we only link to them, so judge them for yourself.
3 hand-picked resources
Free · sign inVideos, official docs and articles covering the same ground, each opened and annotated by hand. They are what you check the assistant against on a day you cannot yet catch it being wrong.
Build it
50 minTake an application you know and draw three versions: a monolith, a modular monolith with named modules and their data ownership, and a microservices split. For the microservices version, list every network call that used to be a function call and what happens when each one fails.
Recall it
20 minAnswer out loud, reveal, then mark honestly whether you had it. That score is the only thing on this page you do not get to choose.
5 recall questions
Free · sign inQuestions you answer from memory, then grade yourself against the real answer. The score is carried into the mastery rating below it, so an honest miss cannot quietly become a tick.
Rate it
Completion and mastery are tracked separately. Be honest, because an inflated rating only means the concept resurfaces sooner.
Mastery tracking
Free · sign inRate yourself against five named criteria per concept. Completion and mastery are tracked separately, and anything you rate shakily comes back automatically on a spaced schedule.
Recap
- 01Microservices mainly solve an organisational problem, not a technical one
- 02Every split turns a function call into something that can fail
- 03A boundary that forces two services to change together is misplaced
- 04The modular monolith keeps the option without paying the cost
Your progress
Free · sign inMark days complete, pick up where you left off across devices, and watch completion and mastery diverge. Free, and the account exists only so ninety days of work cannot vanish with a cleared browser.