Full-stack engineering
At Atomic Concept, we develop the backend, frontend and integrations as parts of one system. An engagement can cover a new module, an extension to an existing application or product maintenance. Below are the technologies and engineering practices we use in that work.
Scope and technologies
Backend, frontend and integrations within one project.
The work includes server logic, data models, user interfaces and connections to external services. We can develop one area of a product or carry a change through every application layer. In an existing project, we first review its architecture, contracts and release process.
| Area | Technologies and practices |
|---|---|
| Backend | Node.js, TypeScript, REST APIs, Zod, asynchronous jobs and webhooks. |
| Data | PostgreSQL, SQL, Prisma, transactions and schema migrations. |
| Frontend | React, Next.js, TanStack Query, MUI, responsive layouts and Core Web Vitals. |
| Integrations | Stripe, Shopify, OAuth 2.0, authentication, authorisation and API keys. |
| AI | Model integrations, structured output, MCP, provider error handling and cost control. |
| Tests and deployment | Vitest, Playwright, GitHub Actions, Docker, Vercel, Cloudflare, logs and monitoring. |
Architecture and reliability
Explicit data contracts and controlled side effects.
Application modules follow responsibilities and business processes. In larger systems, we use DDD and separate write operations from queries through CQRS. Not every project needs this structure. What matters is that module boundaries are clear and a change in one area does not cause unrelated changes elsewhere.
Shared TypeScript contracts and Zod schemas describe API inputs and responses. We can generate data transfer object (DTO) types from the Prisma schema and check that validation and responses match them during compilation and CI. Incoming data still needs runtime validation even when the frontend and backend share the same types.
Integrations account for retries, duplicates and partial failures. A payment webhook should not apply the same operation twice. Related data changes belong in a transaction; emails and other external effects follow its commit. Background jobs need execution control, an error history and a way to resume.
From code change to deployment
Review, tests and verification of the running release.
Before implementation, we agree the behaviour and how to verify it. Changes go through type checking, code review and tests appropriate to the risk: unit, integration or end-to-end. We also check permissions, invalid input, form behaviour and the effect of a failed request.
The release process includes environment configuration, migration checks, deployment and verification of the running version. We agree a rollback approach and how to observe errors after release. Logs should connect a problem with the operation, environment and application version.
When coding agents are involved, tasks, context and change boundaries are defined in advance. Generated code goes through the same review and tests as any other change. Contract work can cover an independent task, module development or ongoing technical support for a product. To define the scope, describe the current system, the change you need and any important technical constraints.