Splitting a Bounded Context, With the ADR Attached
ADR 04 extracts the reservation-change process out of Sales, lists ten steps and two recommendations - and nine of the ten steps are traceable to real code.
Archive
Every article
Newest first, grouped by year. Search or filter by topic.
- 556 articles
- 136 matching
All
.NET
AI Engineering
Architecture
Azure & DevOps
Data Warehousing
Engineering Practice
Microservices
Web APIs
The Snapshot With No Version
ADR 04 names one risk in prose - changing a reservation on stale information - and the table built to mitigate it has no version, no timestamp and no concurrency check.
The Contract That Became Someone Else's Migration
One published type from the Communication module is mapped as an owned entity into TimeManagement's schema - so adding a field to your own contract now needs a migration you do not own.
Your Contract Project Is Not Your Contract
Seven of thirteen published integration events in GroupFlights have exactly one consumer - the module that published them - and one has none at all.
A Gentleman's Agreement Across Thirty-Five Projects
ADR 01 chose a verbal ban on illegal project references over an automated architecture test - and the ban held perfectly, in an estate whose database boundary has no enforcement at all.
The Only Legal Edge Between Modules
Seven contract projects are the estate's entire cross-module surface - and one misplaced marker interface drags the dispatcher framework into two of them by copy-paste.
Three Boxes That Were Never Built
Three of the ten contexts on the context map have no code behind them - and reading the absences carefully separates a design placeholder from a forgotten promise.
The Context Map the Compiler Drew
A repeatable twenty-minute method for deriving a real context map from the project graph and the event subscriptions - then diffing it against the one on the wall.
The Context Map They Drew
ADR 03 declares six relationship patterns across ten bounded contexts and gives a reason for each - read on its own terms, before any code is checked against it.
Eight Modules, Three Architectures, One Domain
GroupFlights picks a different application architecture per module on purpose - and the module nobody singled out turns out to hold the only real aggregate in the estate.
The Repo That Ships Its Own Design Decisions
Most repositories ship code and a README - this one ships four ADRs with a named approver, a context map, a domain message flow and a methodology poster. Part 1 of a series that reads the strategic half of DevMentors' GroupFlights.
The Road Out of the Monolith
Which of ModularMonolith's three modules could become a service tomorrow, what blocks the other two, and the hardening bill the sample never pays - a retrospective on the modular monolith as a station, not a destination.
Two Modules, Three Months of Drift
Conferences and Speakers disagree on layout, naming, id policy, exception visibility, mapping style and route constraints - plus a 200 that returns nothing and a broker that threw NotImplementedException for four months. The honest ledger.
Exception Names Become Error Codes
One middleware turns ConferenceNotFoundException into the wire code conference_not_found via Humanizer - a naming convention promoted to API contract, with a 400-versus-404 tension and Error-level logs it never resolved.
Invariants Enforced by Comment
ModularMonolith's entities are public-setter data bags, its one immutability rule is a fixup with a comment, and its hardest domain question is asked in a comment and answered by nothing - a reading of domain modelling by annotation.
Two Repositories, One Winner
Conferences registers in-memory and EF repositories for the same interfaces and lets last-registration-wins pick - a live lesson in DI as strategy selector, dead registrations as fossils, and a no-op UpdateAsync nobody deleted.
One Flag, Two Failure Modes
A single boolean in appsettings decides whether ModularMonolith's events run inside your HTTP request or on a background pump - and each setting fails differently. Delivery semantics, read honestly from a ternary.
The Database Splits Before the App Does
One Postgres database, one schema per module, and entity configurations that are all empty bodies - what ModularMonolith's data layer declares about future service boundaries, and what its migrations quietly gave away.
One Rename Broke the Only Contract
The last commit of ModularMonolith renames Name to ConferenceName in the subscriber's copy of its one integration event - and the JSON translator has delivered null into that field ever since. Anatomy of a silent contract break.
An Event Bus in Seven Files
ModularMonolith builds its message broker from System.Threading.Channels and one BackgroundService - a textbook Message Channel and Event-Driven Consumer in miniature, with every missing enterprise-integration pattern visible by its absence.
Serialize, Deserialize, Deliver
ModularMonolith routes events between modules by class name and converts them by JSON round-trip - a one-line Message Translator that lets modules share contracts without sharing types, at a price the next part collects.
Startup Order Is Load-Bearing
The last commit of ModularMonolith moves one line of Startup from first to last - and the whole cross-module event system depends on it. Assembly scanning, throwaway service providers and migrations inside ConfigureServices.
Add, Use, Repeat — The Module Recipe
Every module in ModularMonolith plugs in through the same Add/Use extension pair - a recipe small enough to memorise, complete enough to be a mini-framework, and visible even where a module registers nothing at all.
The Compiler Guards the Module Border
ModularMonolith makes every controller internal and teaches MVC to find them anyway - compile-time module isolation from one feature provider, an InternalsVisibleTo chain, and the one place the wall has a hole.
Three Modules, One Process
DevMentors' ModularMonolith sample packs three conference-system modules, a mini-framework and one deliberately broken contract into eighty-four C# files - opening a series that reads all of it, defects included.