Posts

From Idea to Proof of Concept to MVP – 3 article series

/in

This is a a developer focused guide in three parts to evolving code, architecture, and processes with the purpose of turning a raw concept into a usable product. This process is one of the hardest parts of software development.

Teams often jump into implementation too early, or they build something polished before testing whether the underlying assumptions hold.

A structured flow—Idea → Proof of Concept (POC) → Minimum Viable Product (MVP)—keeps this journey predictable and reduces waste.

Each stage exists for a specific reason, and each stage demands a different mindset about code quality, design rigor, and security.
For developers, this is also a shift in how code is written, reused, refactored, and prepared for production.
This article explains the journey from the perspective of engineering teams, with practical backend and frontend examples and a clear separation of security activities.

The Idea

A raw concept describing a problem and a possible technical direction. It has no validated assumptions.

At this point, teams focus on understanding why the problem matters and what a potential solution could look like. No production-ready code exists yet.

Read the full article: From Idea to Proof of Concept to MVP: The Idea stage (1/3)

The Proof of Concept (POC)

A disposable implementation created to validate one or two critical assumptions. The focus is feasibility, not quality.

The POC answers narrow engineering questions such as: Can this API be used to implement the idea? or Can the frontend render this interaction reliably?

Code is expected to be thrown away or heavily rewritten later.

Read the full article: From Idea to Proof of Concept to MVP: The POC stage (2/3) .

The Minimum Viable Product (MVP)

A functional, small-scope product that solves a real user need with the minimum set of features.

Unlike a POC, the MVP requires maintainable code, basic architecture, observability, initial security measures, and repeatable engineering processes.

It is the first version that can be deployed and measured with real users.

Read the full article: From Idea to Proof of Concept to MVP: The Minimum Viable Product – MVP (3/3)

The post From Idea to Proof of Concept to MVP – 3 article series first appeared on Sorin Mustaca’s blog.

From Idea to Proof of Concept to MVP: The Minimum Viable Product – MVP (3/3)

/in

We continue the series of 3 articles with the second one, about the Minimum Viable Product (MVP).

Here is the first article in the series, From Idea to Proof of Concept to MVP: The Idea stage (1/3) and the second article, the From Idea to Proof of Concept to MVP: The POC stage (2/3) .

3. The Minimum Viable Product (MVP)

Once the team has validated feasibility, the work shifts to building a usable, reliable product with a minimal but complete set of features.
The MVP is the first version that serves real users and collects real feedback.

Code quality, architecture, and processes now matter because the MVP becomes the foundation for all future iterations.

Purpose and Scope

The MVP implements the core value with enough stability, scalability, and security to run in production.
It does not include every possible feature—only the essentials—but it must be well-engineered.

Inputs and Outputs

Inputs include the validated POC, UX designs, refined requirements, and mandatory security needs.
Outputs include a deployable product, operational metrics, user feedback, and a backlog for enhancements.

Actors

The full engineering team is involved: backend, frontend, QA, DevOps, Security, UX, Product, and Operations.
Cross-team communication becomes essential, because making the MVP stable requires alignment across all disciplines.

Engineering Expectations at This Stage

Code Quality and Reuse

Developers now take the core logic from the POC and turn it into production-ready modules.
This involves consistent naming, clear responsibilities, robust error handling, schema validation, and test coverage.
The team extracts reusable libraries, shared components, or service interfaces to avoid future duplication.
The MVP becomes the beginning of a long-term codebase.

Required Technical Changes

  • Transform API drafts into versioned, documented REST or GraphQL interfaces.

  • Move throwaway scripts into properly structured modules or services.

  • Add input validation, sanitization, and schema enforcement.

  • Introduce unit tests, integration tests, and E2E tests.

  • Replace temporary mock data with real data pipelines.

  • Add observability: logs, metrics, traces, dashboards.

  • Integrate with continuous delivery pipelines.

Process Evolution

The team adopts formal processes:

  • CI/CD, code reviews with defined guidelines, branching strategies, automated testing, deployment checklists, and observability standards.
  • Documentation becomes mandatory because the product is no longer experimental.

Backend Example

The recommendation engine becomes now a stable service.
The POC endpoint turns into a versioned API with full request validation, structured logging, retry logic, error mapping, and test coverage.
The integration with the ML service now uses proper authentication, rate limiting, and timeouts.
Monitoring dashboards track latency, throughput, and error rates.

Frontend Example

The rough POC component becomes part of the application’s design system.
It uses reusable UI components, handles loading and error states gracefully, and integrates with the global state store.
Unit tests confirm component behavior, tests validate the full user flow.
Telemetry captures user interactions so the team can validate assumptions after launch.

Security

Security now moves from conceptual and experimental checks to real, enforceable controls.
This includes:

  • Authentication and authorization integration

  • Input validation and output encoding

  • Protection against injection vulnerabilities

  • HTTPS enforcement and secure cookie settings

  • Audit logging

  • Secrets management

  • Data-handling guarantees for sensitive information

The MVP does not need every advanced security feature, but it must meet the minimum standards required for production—especially if it processes personal or regulated data.

Here is the first article in the series, From Idea to Proof of Concept to MVP: The Idea stage (1/3) and the second article, the From Idea to Proof of Concept to MVP: The POC stage (2/3) .

The post From Idea to Proof of Concept to MVP: The Minimum Viable Product – MVP (3/3) first appeared on Sorin Mustaca’s blog.

From Idea to Proof of Concept to MVP: The POC stage (2/3)

/in

We continue the series of 3 articles with the second one, about the Proof of Concept (POC).

Here is the first article in the series, From Idea to Proof of Concept to MVP: The Idea stage (1/3) .

2. The Proof of Concept (POC)

The POC is where the team tests a specific risky assumption that could make or break the idea.
The aim is not to build a usable product but to verify that a key technical, architectural, or data-processing challenge is solvable.

POC code is intentionally imperfect. It moves fast and cuts corners. However, it should still be written in a way that reduces friction when extracting reusable parts for the MVP.

What Defines a POC

  • A POC is short-lived and narrowly focused. It often tests only one or two questions:
    Can we integrate with this external system?
  • Can this algorithm scale?
  • Can the frontend render a dynamic timeline with the required performance?

The purpose is to generate a clear yes/no answer, not to produce a polished outcome.

Inputs and Outputs

Inputs include the problem statement and hypothesis defined in the idea stage.
Outputs include a working demonstration, documentation of findings, architectural constraints, and a clear decision: continue, pivot, or stop.

Actors

Developers implement the experiment.
Tech leads help evaluate results.
QA may help with validation but does not perform full product testing.
Security engineers review risks that appear during the experiment.

Engineering Expectations at This Stage

Code and Reuse

POC code is disposable, but that does not mean it should be sloppy. Developers should write code that can be extracted later without major re-architecture. This typically means:

  • Avoid hardcoded credentials, external URLs, or secrets.

  • Organize files in a simple but meaningful structure.

  • Implement the core logic in isolated modules instead of burying it inside an ad-hoc script.

  • Use interfaces or adapters to make future dependency injection easier.

The mindset should be: “This code may be thrown away, but if it works well, we want to reuse pieces of it.”

What Must Change Later

Before integrating POC code into the MVP, the team will need to refactor it: add error handling, consistent logging, tests, and proper abstractions.
In other words, the POC shows the core idea works, but the MVP requires turning this into real engineering.

Process Evolution

The POC often introduces small process steps such as:

  • Lightweight code reviews

  • A temporary branch in the repository

  • Simple build scripts to allow teammates to run the demonstration

This is still not production engineering. CI/CD pipelines and test automation usually come only at the MVP stage.

Backend Example

Suppose the team is building a new recommendation engine.
The backend POC might implement a single endpoint that forwards a request to an external ML service and measures latency and response quality.
Logging might be minimal, validation might be non-existent, and error handling might be crude—but the team learns whether the external ML service meets the performance requirements.

Frontend Example

A frontend POC might involve building a rough React component that displays personalized recommendations using mock data.
The component may not follow the design system, may not handle loading states cleanly, and may ignore error cases.
The goal is to check whether the UI interaction model feels intuitive and whether the state updates behave as expected.

Security

Security engineers examine how the POC handles sensitive data, even if the handling is mocked.
They validate risky paths such as authentication flows, data transformation logic, or external integrations.
The POC must identify whether the solution will require additional compliance measures, encrypted storage, or stricter authentication schemes.
This becomes a mandatory input for the MVP.

The post From Idea to Proof of Concept to MVP: The POC stage (2/3) first appeared on Sorin Mustaca’s blog.

From Idea to Proof of Concept to MVP: The Idea stage (1/3)

/in

This is a a developer focused guide in three parts to evolving code, architecture, and processes with the purpose of turning a raw concept into a usable product. This process is one of the hardest parts of software development.

Teams often jump into implementation too early, or they build something polished before testing whether the underlying assumptions hold.

A structured flow—Idea → Proof of Concept (POC) → Minimum Viable Product (MVP)—keeps this journey predictable and reduces waste.

Each stage exists for a specific reason, and each stage demands a different mindset about code quality, design rigor, and security.
For developers, this is also a shift in how code is written, reused, refactored, and prepared for production.
This article explains the journey from the perspective of engineering teams, with practical backend and frontend examples and a clear separation of security activities.

Legend

Idea
A raw concept describing a problem and a possible technical direction. It has no validated assumptions.

At this point, teams focus on understanding why the problem matters and what a potential solution could look like. No production-ready code exists yet.

Proof of Concept (POC)
A disposable implementation created to validate one or two critical assumptions. The focus is feasibility, not quality.

The POC answers narrow engineering questions such as: Can this API be used to implement the idea? or Can the frontend render this interaction reliably?

Code is expected to be thrown away or heavily rewritten later.

Minimum Viable Product (MVP)
A functional, small-scope product that solves a real user need with the minimum set of features.

Unlike a POC, the MVP requires maintainable code, basic architecture, observability, initial security measures, and repeatable engineering processes.

It is the first version that can be deployed and measured with real users.

Transition: Idea → POC
The transition tests feasibility. Only the highest-risk technical assumptions are validated. Success means the idea has enough technical grounding to justify investment.

Transition: POC → MVP
The transition focuses on turning validated feasibility into a real product. Teams refactor or rebuild the POC code into production-ready components. Architecture stabilizes, security controls appear, and processes become repeatable.

1. The Idea Stage

The idea stage is where the team defines the problem and shapes the first version of the solution direction. The discussion is broad, and uncertainty is still high.

At this point the team is not writing code in any meaningful sense, but rather exploring possibilities, boundaries (technological, legal, usability related), and early risks.

The goal here is not to “design the whole system”. The goal is to understand whether the idea is worth testing and whether the technical foundation appears feasible. This prevents teams from sinking time into something that cannot work or is not worth the investment.

What Makes This Stage Unique

The idea stage is low-cost, low-risk, and exploratory. Developers participate mainly by assessing feasibility, identifying potential architectural constraints, and sketching which components might be reused later. The conversation stays intentionally shallow. Nothing should be implemented that the team cannot abandon without regret.

Inputs and Outputs

Inputs include the product need, early UX sketches, discussions about the problem, and high-level constraints such as data privacy, integration requirements, or performance expectations.
Outputs include a defined problem statement, a preliminary solution outline, and a clear hypothesis that the POC must validate.

Actors

Product managers frame the problem. Engineering leads assess feasibility. UX designers shape initial user interactions. Security architects provide early warnings about potential data-handling or compliance pitfalls.

Engineering Expectations at This Stage

Code and Architecture

No production code is written. If developers create anything, it is lightweight and disposable:
simple mock APIs written in Postman collections, small HTML/JS mockups, or rough OpenAPI drafts.
Nothing created at this stage is meant to be reused directly, but these drafts help teams align on concepts.

However, developers should already think about potential reuse paths.
For instance, if the solution will likely need a shared data-access layer or a reusable front-end state-management module, this is the time to name those opportunities—even if nothing is implemented.

Process Implications

The team documents assumptions, potential dependencies, and cases where reuse might save time later.
There is no review process, no CI pipeline changes, and no branching strategy decisions.
This remains a design and exploration stage.

Backend Example

A backend developer might sketch a future architecture in AWS or draft a sequence diagram showing how the system would communicate with an external payment service.
They might explore the integration constraints by reading documentation and checking rate limits, but no or very little code is produced.

Frontend Example

A frontend developer might draft wireframes and map out how new UI states could fit into existing structures.
They might also check whether existing UI components can be repurposed to avoid re-inventing layout patterns later.

Security and Privacy

Security work is limited to conceptual analysis. No real data is supposed to be used in this stage, so privacy concerns should not exist.
Security architects identify which data categories will be processed, assess whether regulatory frameworks apply, and highlight technical constraints that must be tested in the POC.
No security implementation takes place at this stage, but early awareness helps avoid blind spots later.

The post From Idea to Proof of Concept to MVP: The Idea stage (1/3) first appeared on Sorin Mustaca’s blog.