PRODUCT ENGINEERING / SYSTEM NODEBackend & APIs

Backends built for production load, failures, and visibility.

A backend that works in development is not the same as one that holds up under load, handles partial failures gracefully, and gives your team visibility to diagnose problems.

Delivery evidence
Ownership, deployment boundary, acceptance criteria, and handover are defined per engagement.
routes/api.ts
// Contract-first — spec before implementation
 
import
 { Router } from 'express'
import
 { validate } from './middleware'
 
router.post
('/orders', validate(schema), async (req, res) => {
  const order = await db.orders.create({
    ...req.body,
    status: 'pending',
  })
 
  await queue.publish('order.created', order)
 
  return res.status(201).json({ id: order.id })
})
BUILD / READY
WHAT WE BUILD

Backend & APIs, engineered as an operating system.

Scope follows the real workflow, environment, failure modes, and ownership model rather than a fixed vendor package.

01

REST & GraphQL APIs

Versioned, documented APIs with consistent error handling, rate limiting, and authentication built in from the start.

  • OpenAPI / GraphQL schema
  • Versioning strategy
  • Rate limiting & auth
02

Database Design & Optimisation

Schema design, indexing strategy, query optimisation, and controlled migration plans for PostgreSQL, MySQL, and document databases.

  • Query explain analysis
  • Index strategy
  • Migration runbooks
03

Authentication & Authorisation

Secure implementation of OAuth 2.0, JWT, session management, and RBAC — built on proven libraries, not custom cryptography.

  • OAuth 2.0 / JWT
  • RBAC & policy engine
  • MFA integration
04

Microservices Architecture

Service decomposition, inter-service communication patterns, and deployment isolation for systems that need independent scaling.

  • Service boundaries
  • Inter-service comms
  • Independent deploys
05

Observability

Structured logging, distributed tracing, and alerting that surfaces failures before users report them.

  • Structured logs
  • Distributed tracing
  • Alerting & runbooks
DELIVERY SEQUENCE

From unknowns to production evidence.

01

Architecture Review

Define the target architecture, service boundaries, database schema, and non-functional requirements before any code is written.

Requirements Architecture Doc
02

API Contract

Write the OpenAPI specification before implementation. Frontend, backend, and external consumers agree on the contract first.

Architecture API Spec
03

Database Design

Schema design, indexing strategy, and controlled migration planning, including low/zero-downtime patterns where the system requires and supports them.

API Spec Database Design
04

Implementation

Iterative endpoint implementation with integration tests running against each pull request. No untested code merged.

DB Design Working API
05

Load & Security Test

Load test against realistic traffic profiles. Security review covering OWASP Top 10 and authentication edge cases.

Working API Tested API
06

Deploy & Observe

Production deployment with structured logging, distributed tracing, and alerting configured. Runbooks written before go-live.

Tested API Live API
TECHNOLOGY SURFACE

Tools selected for the system, not the trend.

Technology follows environment, operating constraints, team ownership, and long-term maintainability.

01Languages

Node.js · Python · Go · TypeScript

02Frameworks

Fastify · Express · FastAPI · Django REST

03Databases

PostgreSQL · MongoDB · Redis · MySQL

04Observability

OpenTelemetry · Grafana · Prometheus · Sentry

WHERE IT FITS

The same capability changes by domain.

01

Technology

Platform APIs, developer tooling backends, SaaS core services, webhook systems.

02

Finance

Payment processing APIs, trading backends, core banking integration, compliance reporting.

03

Healthcare

FHIR-compatible health data APIs, appointment booking, EHR integration backends.

04

Retail

Order management APIs, inventory sync, pricing engines, fulfilment backends.

TECHNICAL FAQ

Questions worth resolving before delivery.

01Do you write OpenAPI documentation?+

Yes, contract-first. We write the OpenAPI spec before implementation begins — it serves as the agreed interface between all consumers.

02How do you handle database migrations in production?+

With versioned, idempotent migrations via Flyway or Alembic. Low/zero-downtime migration patterns can require additive changes and multi-phase deploys; feasibility depends on the application, database, and cutover constraints.

03What load testing tools do you use?+

k6 for scripted scenarios, Gatling for complex simulations. Load targets are defined in scoping and tested against before handover.

04Do you implement authentication or just design it?+

We implement it — including edge cases like token refresh, session invalidation, concurrent login handling, and MFA. Implementation details matter more than the design here.

OSYSTIC / PROJECT CHANNELOPEN
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