Designing Software Architecture for Scale

Author
Nam Pham
The MVP Trap (I’ve been there)
When building an MVP, speed is everything. You just want to ship. So naturally, you:
- Put business logic directly in controllers
- Use a single database for everything
- Skip boundaries because “we’ll refactor later”
The problem is… “later” comes faster than expected.
One day your product suddenly has:
- 10x more users
- Multiple teams working on the same codebase
- Real enterprise clients asking for SLAs, security, audit logs…
And then your architecture starts fighting you.
Decision #1: Separate Domain Logic Early (Even a Little)
I used to think Clean Architecture was overkill for MVPs. Now I think full Clean Architecture might be overkill — but ignoring separation entirely is worse.
A simple rule I follow now:
Keep business logic out of delivery layers (API, UI)
Even just having:
- services/ or use-cases/
- instead of putting everything inside controllers
This makes it much easier to:
- reuse logic later
- test things without spinning up the whole app
- migrate to microservices (if needed)
Decision #2: Design for Read Scalability First
Most apps scale reads before writes.
Instead of over-engineering:
- Start with a monolith
- But make it read-friendly
Some practical things I’ve been trying recently:
- Introduce caching early (Redis, even simple in-memory)
- Separate read models (basic CQRS-lite, nothing fancy)
- Use pagination everywhere (seriously, everywhere)
You don’t need full CQRS — just don’t assume one DB query will always be cheap.
Decision #3: Be Careful With “Shared Database Everything”
This one hurts.
At MVP stage, one database is fine. But:
Sharing the same schema across multiple features without boundaries becomes a nightmare.
What helped me:
- Group tables by domain (even in same DB)
- Avoid cross-domain joins unless really necessary
- Use APIs internally instead of direct DB access (even if same codebase)
It’s like pretending you have microservices… without actually suffering from them yet.
Decision #4: Async First (Where It Makes Sense)
A mistake I made:
Everything was synchronous because it was easier.
Later:
- slow APIs
- timeouts
- bad UX
Now I try to identify early:
- emails → async
- reports → async
- heavy processing → async
Tools I’ve experimented with recently:
- message queues (Kafka, RabbitMQ)
- lightweight job queues (BullMQ, Sidekiq-like systems)
You don’t need to go “full event-driven”, but having async boundaries helps a lot.
Decision #5: Observability Is Not Optional Anymore
This is something I ignored until production issues happened.
Now even in MVP, I try to include:
- structured logging
- basic tracing (OpenTelemetry is getting easier to adopt)
- metrics (even simple ones)
Because when scaling happens:
You can’t fix what you can’t see.
Some Newer Things I’m Exploring
Lately I’ve been experimenting with:
- Serverless + edge functions (for scaling reads globally)
- Backend-for-Frontend (BFF) pattern for complex UI
- Using GraphQL selectively (not everywhere like before 😅)
- AI-assisted monitoring (still early, but interesting)
Not all of these are necessary — but they’re changing how I think about scalability.
Final Thought
You don’t need perfect architecture at MVP stage.
But you do need:
- clear boundaries
- awareness of future scaling points
- and discipline to avoid “temporary hacks” becoming permanent
Because the real cost isn’t building fast —
it’s rebuilding everything later.