Backend Development

APIs, data, and systems engineered for performance, security, and growth.

Backend DevelopmentAPI DevelopmentPostgreSQLSystem Architecture
Rails
NextJS
GraphQL
Phoenix
NodeJS
PostgreSQL

Backend development means building the server-side systems behind a product: APIs, databases, authentication, and integrations that keep data consistent and available. At Hardihood, we design backends as product infrastructure, to the same standard as our strategy, design, and frontend work.

Backends fail slowly. The schema that felt fine at a hundred records becomes the reason a page takes nine seconds at a hundred thousand. The permission check copied into twelve controllers becomes the reason one customer can see another customer's data. Most of what we do is make those decisions carefully the first time, and fix them carefully when someone else did not.

What we build

We build the server-side systems that make products trustworthy. Typical engagements:

  • APIs and service layers

    Clear HTTP or GraphQL interfaces that keep clients, partners, and internal tools in sync.

  • Data models and persistence

    PostgreSQL schemas, migrations, and query patterns designed for correctness and growth.

  • Auth and permissions

    Sign-in, roles, and access rules that protect sensitive workflows without slowing teams down.

  • Integrations and real-time systems

    Webhooks, queues, WebSockets, and third-party connections that keep the product moving.

What teams hire us to build

Backend work rarely arrives as an abstract request for an API. It usually shows up as one of these.

  • New product backend

    Greenfield API, schema, and auth for a product going from nothing to first customers, built so the early decisions do not become next year's rewrite.

  • Multi-role platforms

    Systems where several distinct audiences share data but need different permissions, dashboards, and workflows from the same source of truth.

  • Payments and payouts

    Checkout, stored cards, retries, refunds, and multi-party payouts, including Stripe Connect flows that split revenue between several parties.

  • Background processing

    Durable job pipelines for escalations, reminders, retries, and anything else too slow or too failure-prone to run inside a web request.

  • Legacy modernization

    Stabilizing an aging backend, improving database health and query performance, and migrating data without taking the product offline.

  • Internal and admin tooling

    The operations software your team uses to actually run the business, which is usually the first thing cut and the first thing missed.

How we approach backend development

We treat the backend as product infrastructure, not a black box. Reliability, clarity, and changeability stay in scope from day one.

  1. 1

    Clarify product and load needs

    Understand the workflows, data sensitivity, and scale expectations before choosing architecture.

  2. 2

    Design the system boundaries

    Map services, APIs, and ownership so the backend stays understandable as features multiply.

  3. 3

    Build for reliability

    Implement core paths with strong validation, observability, and failure handling from the start.

  4. 4

    Integrate and harden

    Connect external systems carefully, then test the edge cases that show up under real traffic.

  5. 5

    Operate and evolve

    Ship with monitoring, then refine performance, cost, and maintainability as usage grows.

What backend development costs and how long it takes

Every engagement below ships with automated tests, monitoring, and a deployment pipeline. Those are not upgrades.

EngagementTypical timelineWhat it covers
Architecture review1 to 2 weeksAn assessment of an existing backend: reliability risks, data model problems, performance bottlenecks, and a prioritized plan to address them.
Focused backend build4 to 9 weeksAn API, data layer, auth, and the integrations one product surface needs, delivered with tests, monitoring, and deployment pipeline.
Full platform build9 to 16 weeksEnd-to-end product infrastructure including multi-role permissions, payments, background processing, and admin tooling.

What moves the number

  • How many third-party systems the backend integrates with, and how well those APIs behave
  • The number of distinct user roles and how differently each one sees the data
  • Whether money moves through the system, which raises the correctness and audit bar sharply
  • How much existing data has to be migrated, and whether that can happen with downtime
  • Whether admin and reporting tooling is in scope or handled elsewhere

We scope to a fixed price after discovery. If your product would be better served by an off-the-shelf platform than a custom backend, we will tell you that before you spend anything.

Custom backend vs. off-the-shelf platforms

Teams often ask us whether to buy a platform or build a backend. The difference changes control, cost, and how unique your product logic can be.

Platform / BaaSCustom backend
Speed to startOften faster for common patternsFaster when requirements are unusual or tightly coupled
FlexibilityLimited by vendor boundariesShaped around your domain, data, and workflows
Long-term costCan rise with usage and add-onsHigher upfront, more control over growth and ops
Best fitStandard CRUD and early prototypesDifferentiated products with serious reliability needs

Bottom line: buy when the platform fits the product. Build when the backend is part of how you compete.

The stack we reach for, and why

We are not loyal to a framework. We are loyal to small teams being able to operate what we hand them, which usually points at boring, well-understood tools.

Ruby on Rails

Our default for products where a small team needs to move fast and keep operating the system afterward. Rails covers an enormous amount of ground out of the box, which means less bespoke infrastructure to maintain. Polarity runs on Rails 8 with Hotwire.

Node.js and Next.js server capabilities

A good fit when the team is already TypeScript-heavy and the backend work sits close to the frontend, letting one language and one deployment cover both.

Elixir and Phoenix

Worth reaching for when the product is genuinely real-time or concurrency-heavy, where the runtime does work that would otherwise require significant custom engineering.

PostgreSQL, always

Relational by default. Most products that reach for something exotic early end up reimplementing joins and transactions later. Postgres handles far more scale than most teams expect, and it fails in ways that are well documented.

What reliable actually means

Reliability is not a feature you add at the end. In practice it is a handful of unglamorous commitments: validation at the boundary so bad data never lands, explicit failure handling for every external call, durable background jobs with retries for anything slow, an audit trail for anything involving money or permissions, and monitoring that tells you a problem is happening before a customer does.

On Polarity that meant a seven-stage enforcement pipeline running unattended through background jobs, automatic payment retries, and multi-party payouts that had to reconcile correctly every time. Those are the paths where being mostly right is the same as being wrong.

Why teams hire Hardihood for backend development

A backend only earns its place if it matches your product’s real workflows and failure modes. We pair API and data design with the frontend, mobile, and product context so the system stays understandable after launch, not just on day one.

If you're exploring how we partner, see engagement models, browse client work, or read more in our FAQ.

Frequently asked questions

We commonly work with Ruby on Rails, Node.js, Next.js server capabilities, Elixir Phoenix when real-time systems call for it, PostgreSQL, GraphQL, and WebSockets. The stack follows the product’s reliability, speed, and team needs.

Proof: the Polarity platform

We designed and built Polarity end to end: a parking operations platform with passwordless guest checkout, a seven-stage enforcement pipeline, Stripe Connect revenue splits across property owners and towing partners, and five role-based portals. It runs on Ruby on Rails 8 with PostgreSQL, Solid Queue for background work, and Twilio for transactional SMS, with security scanning, linting, and full system tests on every change.

Domain models
41

Domain models

Background job types
15+

Background job types

Role-based portals
5

Role-based portals

Idea to launch and revenue
5 mo

Idea to launch and revenue

They moved quickly while making sure it was built the right way. The launch went smoothly, and we went from idea to launch and revenue in just five months.
Jake Gannon, Founder, Polarity
Read the Polarity case study

Related services

Related reading

  • Polarity case study

    A multi-portal platform with Stripe Connect payouts, enforcement pipelines, and 41 domain models.

  • Gravy case study

    Rails API work, PostgreSQL reliability, and admin tooling for a renter rewards product.

  • App security best practices

    The authorization, secrets, and data handling work we build in, plus the AI-specific risks.

Need a backend that can grow with you? Let’s map the architecture.

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