Home
Services
Custom Software
API, Database & Auth

[ Platform service ]

API, Database & Auth — built properly, handed over completely.

Reliable backend systems covering database design, secure authentication, APIs, and integrations.

CATEGORY Custom SoftwareSTACK 3 platform tagsPROOF 2 case studies available

[ What you get ]

5 deliverables. Nothing implicit.

Data model: The schema designed around access patterns, with migrations versioned.You own: Versioned schema and migration scripts
API design: Endpoints specified with contracts, errors, and versioning decided up front.You own: An OpenAPI-class contract plus the implementation
Auth flows: Authentication and authorization implemented with sessions and tokens handled properly.You own: Working auth with a security review
Integrations: Third-party services and webhooks connected with failure states handled.You own: Verified integrations with their contracts documented
Security review: Access control, injection risks, and secrets reviewed before launch.You own: A security review document
Done means: Done means the API serves the contract under load tests, auth resists the checklist in the security review, and migrations run forward and back cleanly in your infrastructure.
Not included: Infrastructure and database licensing costs are yours; SOC2-class certification audits are a separate compliance engagement.

$3k–$15k

Typical focused build, fixed price

3–6

Weeks from kickoff to handover, typical

100%

Owned by you at handover

[ How it works ]

The api, database & auth engagement, phase by phase.

Discover & scope: We map how api, database & auth fits into your current stack, then agree a written scope with the acceptance criteria attached before work begins.
Plan & architect: The implementation plan records the structure, boundaries, and integration points, so build decisions are documented rather than improvised.
Build & integrate: Implementation covers data model and api design in reviewable increments against the agreed plan.
Verify & hand over: We verify the acceptance checks, close the engagement out with security review, and hand over documentation your team can operate without us.

[ Capabilities ]

The surface area of a api, database & auth build.

The platform and discipline surface we work across — what an engagement can cover when the scope calls for it.

Schema design

Normalization, indexing, and access-pattern-first modeling.

Migrations

Versioned, reversible migrations that never surprise.

REST & GraphQL APIs

Contracts specified before code, versioned after.

Authentication

Sessions, tokens, OAuth flows, and MFA where needed.

Authorization

Role and permission models enforced server-side.

Webhooks & events

Reliable delivery with retries and idempotency.

Rate limiting & abuse

Limits and quotas that protect your systems.

Secrets management

Key rotation and storage done properly.

Observability

Logging and tracing that make incidents debuggable.

[ Field notes ]

How we think about api, database & auth.

Why a dedicated backend foundation: The backend is where data, identity, and integrations meet, so getting it right protects everything built on top. Reliable backend systems give frontends, mobile apps, and third parties a dependable layer to connect to.
Who the service is for: This service suits products that need a solid data model, secure authentication, and clean APIs before features can scale. It also fits teams replacing ad-hoc backend code with an architecture built to last.
What the build delivers: Deliverables include the data model, API design, auth flows, and a security review. Each phase is sized to give the product a backend foundation that other services can rely on.
Discovery and architecture assessment: The project starts with software architecture choices such as microservices and event-driven design where they fit. The data model and its relational vs NoSQL basis are decided against the product's data needs.
Technical build and data model: Database design and data modeling produce the data model, with data migrations keeping schema changes safe. API design using REST or GraphQL exposes that data to clients with clear contracts.
Auth flows and role-based access: Secure authentication and auth flows protect identity, with OAuth used where external authorization is needed. Authorization and role-based access control who can reach each resource.
Integrations and cloud infrastructure: Integrations connect the backend to the external services the product depends on. Cloud platforms such as AWS, Azure, and GCP host the system, with serverless and infrastructure as code keeping deployment repeatable.
Quality, security review, and delivery: A security review checks the data model, auth flows, and API surface for weaknesses before launch. Deployment pipelines (CI/CD) carry changes through a controlled path into production.
Measurement and observability: Observability and monitoring track the backend so failures surface before users notice. API behavior and data integrity are watched through the same tooling.
Handoff and team enablement: The team receives documentation covering the data model, API contracts, and auth flows. This enables internal teams to extend the backend and operate it confidently.
Ongoing care and evolution: Ongoing care covers data migrations, new integrations, and auth changes as the product grows. The architecture stays aligned with evolving needs through the same CI/CD pipeline.
Related services: The backend foundation supports every frontend service, including mobile apps and customer portals. Testing, deployment and support practices carry it into dependable ongoing delivery.

[ Common questions ]

How do you choose between relational and NoSQL?

Database design and data modeling start with how the product reads and writes its data. Relational vs NoSQL is chosen to match the data's shape and access patterns.

What authentication methods do you support?

Secure authentication and auth flows are built into the backend, with OAuth used where external authorization is required. Authorization and role-based access control follow.

What is involved in the security review?

The security review examines the data model, auth flows, and API surface for weaknesses. It happens before launch and is revisited as the backend evolves.

Which cloud platforms do you work with?

The backend can be hosted on AWS, Azure, or GCP, including serverless options. Infrastructure as code and deployment pipelines keep environments reproducible.

How do APIs and databases stay in sync as we change things?

Data migrations and API design are versioned through deployment pipelines (CI/CD). Observability and monitoring confirm changes behave correctly in production.

[ Proof ]

Reference engagements for api, database & auth.

Target metrics for discovery and acceptance — the full reference set is 2 projects deep.

Representative example

Custom Software / API, Database & Auth

A benefits brokerage automated its January: carrier data and SSO across forty employer clients

Manual January pipeline-run enrollmentForty employer clients' elections flowing through adapters with row-level audit, reviewed by exception

Representative example

Custom Software / API, Database & Auth

A cold-chain logistics provider built one telemetry API its customers actually integrate with

Hand-maintained feeds one telemetry APIAll customer integrations served from the normalized model, with the retailer audit passed from an evidence export

[ Sibling platforms ]

[ Field guides ]

Go deeper on api, database & auth.

API design: documenting authentication, errors, and versioning

An API contract should define authentication, authorization, payload validation, error formats, rate limits, versioning, and observability.

4 min read

API, Database & Auth: implementation decisions that shape the build

Reliable backend systems covering database design, secure authentication, APIs, and integrations.

4 min read

[ Next step ]

Start with a scoped proposal. Price attached.

contact@nexsumlabs.com — we reply within one business day

Back to Custom Software