203 articles filed under this topic.
Unit tests mock what you assume, end-to-end tests tell you too late - consumer-driven contract testing closes the gap, and a small open-source .NET library called Pactify is the clearest way I know to learn how it works. Part 1 of a series.
The 22-part Convey series read the packages; it never once walked the sample system that ships with them. Opening the missing chapters with the trip an order takes through Orders, Pricing and Deliveries — and what the samples quietly teach that no package README does.
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.
Every team's fifth microservice ships with the same four hundred lines of bootstrap code as the first four. Opening a deep-dive series on Convey, the open-source .NET toolkit that turned that boilerplate into thirty composable packages.
DShop is one e-commerce shop stamped out as nine microservices over RabbitMQ - this series reads the real source to see how the topology holds together and where it drifts. Part 1 of Nine Services and a Message Bus.
Every modular monolith promises you can extract a module later. Inflow has a branch where someone actually did it - one module lifted into its own process behind a gateway and a real broker. This series reads that branch line by line.
DevMentors built the same e-commerce shop twice - once as a monolith, once as nine services - with two gateways and two frontends. This series reads the whole estate as one artefact.
A guided tour of FeedR, DevMentors' open-source .NET microservices sample for real-time data feeds - six services, Redis pub/sub, Apache Pulsar and a gRPC stream, and the two-tier eventing model that makes it worth reading. Part 1 of a source-level deep dive.
Split one database into five services and the transaction you deleted does not disappear - it goes feral. On sagas, compensation, process managers, and Chronicle, the small open-source .NET library this series reads line by line.
Convey sells a microservice in thirty lines, and Pacco builds ten of them - this series reads the whole estate to price what the framework compresses and what every consumer pays for by hand. Part 1 of The Convey Consumer Tax.
Nobody in Pacco approves an order - a vehicle reservation does. A tour of DevMentors' parcel-delivery estate, the domain it models, and the fifteen-part series it earns.
DevMentors shipped Trill as nine microservice repos, then rebuilt the identical product as a modular monolith three months later - giving us a controlled experiment in architecture that almost never exists in public.
Trill's Stories service is four projects with a dependency-free domain at the bottom. Its Users service is two projects with everything in one assembly - same author, same week, same estate, opposite answers to what a layer is.
The DevMentors Trill estate is a nine-service microservices sample spread over eleven sibling repositories with no README, no clone script and no bootstrap tooling - and the only artefact that names the whole system is a Visual Studio solution file.
Thirteen repositories, one umbrella that runs twelve of them, two interchangeable API gateways and a service that watches everything - the Pacco estate read as a system of systems, and the fifteen-part series it earns.
Trill's API gateway turns HTTP posts into AMQP messages using eighty lines of middleware, a route template and a raw JSON blob - it publishes onto the estate's bus with zero compile-time knowledge of any contract, which is the exact inverse of what every other repo does.
Every exchange and queue in the Trill estate is declared durable, and the RabbitMQ container that holds them has its volume commented out - Guaranteed Delivery configured at the broker and cancelled one file away.
Trill's appsettings files and package references describe caching, service discovery, health checks, dynamic secret leases and API documentation - and reading the source shows how much of that is never wired up at all.
The DevMentors Trill estate is a nine-service microservices sample spread over eleven sibling repositories with no README, no clone script and no bootstrap tooling - and the only artefact that names the whole system is a Visual Studio solution file.
Trill ships a PM2 ecosystem file, a Tye manifest and a Docker Compose file - three ways to start the estate that disagree about which services exist, plus a Prometheus config that scrapes a service two of them never launch.
An honest retrospective on fifteen parts of source-reading - what the decision records bought, what they could not buy, and the compliance gaps nobody wrote down.
Four decision records with a named reporter and approver, no dates, no supersession, an architecture board hosted outside version control and a README that links code by line number.
Two events in GroupFlights have more than one subscriber, and both are where it breaks - two handlers ask "is this mine?" and two do not, in both directions.
A fully built cross-cutting decorator disables an entire context relationship behind a local variable that is always false - while a sibling module enforces the identical rule for real.
The event interface has no members, so nothing can carry a correlation id - and three modules each rebuild the pattern as application state, one of them in a static dictionary with a TODO.
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.
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.
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.
Seven of thirteen published integration events in GroupFlights have exactly one consumer - the module that published them - and one has none at all.
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.
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 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.
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.
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.
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.
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.
Redis registered in nine services and read in one, discovery stacks in services that never call anyone, an outbox package referenced but never wired, and versions that float by construction - an inventory of everything Pacco wires up and never uses.
The retrospective, with the ledger totalled - seven byte-identical MessageBrokers, one AggregateRoot with three meanings, what Convey genuinely optimises, where a Convey.Bootstrap meta-layer should have stood, and what a consumer should copy from this estate.
A refactoring.guru walk through Pacco's real lines - a flags-enum search that can never match, twin guards, a dead password check, mappers that return null, and an Id that is never assigned - each smell named and each paired with the technique that cures it.
The self-styled uber AI order maker resolves to FirstOrDefault behind an in-source confession, and its reservation heuristic structurally out-bids every earlier booking - the estate's data-science audit, written up as the short honest piece its eleven lines deserve.
