Distributed-Systems

Deno’s runtime got a twelve month clock and Deno Deploy got six months, but Deploy had already been shut down once in July, and the part of Deno that survived is the part nobody was arguing about.

When generative AI commoditizes syntax into zero-cost token emissions, the developer’s moat shifts from typing code to systems synthesis: understanding how a single concurrent change ripples across database row locks, cache lines, and cloud bills.

Boundaries, communication styles, technology, and sagas all sound reasonable in isolation. Here’s what it looks like to actually apply all four decisions to one real workflow, in order.

Splitting a monolith means splitting its database transactions too. The instinct is to reach for a distributed transaction. Here’s why that instinct is usually wrong, and what to do instead.

The communication style (sync/async, request-response/event-driven) narrows the field. Here’s how the actual technologies stack up once you’re choosing among them.

In a monolith, a stack trace tells you what went wrong. In microservices, you’re grepping across three services’ logs at 2 AM trying to figure out which one lost the request. Here’s how to make that possible instead of painful.

In a monolith, renaming a field means updating all callers in one commit. In microservices, consumers upgrade on their own schedule, so your API has to evolve without breaking the ones that haven’t upgraded yet. Here’s how.

You split the monolith into twelve services. Now a new developer’s first week is spent getting Docker Compose to run all twelve on their laptop, and half of them crash because of a port conflict. Here’s how to make local development work without the pain.

In a monolith, deploy means pushing one thing. In microservices, every service deploys independently, which is the whole point, until you realize that ‘independently’ also means ‘without knowing what the other services are doing right now.’

Each service owns its database. That’s the rule. But when a report needs data from four services, or a customer wants to see their complete order history, you’ve got a query problem that a single SELECT can’t solve. Here’s how to handle it.