Backend development services
Your users see the interface. Your business runs underneath it: the rules, the data, the integrations, the permissions and the workloads your product depends on. We design and build backend systems that handle all of it reliably and securely, without leaving you with a system your team is afraid to change.
The real problem
Nobody decides to build a fragile backend. It happens one reasonable shortcut at a time, and the cost arrives later, usually as a feature that should take a week and takes a quarter.
The same pricing rule is written in the app, the admin panel and a nightly script, slightly differently each time. Changing it means finding all of them, and someone always misses one.
Two systems each hold part of the truth and slowly drift apart. Nothing errors, so nobody notices until finance, a customer or an auditor does.
Each new partner, payment provider or internal system is another connection built in a hurry. When one of them has a bad day, your whole product does too.
Without tests, clear boundaries and a way to roll back, a two-line change needs a week of checking and a quiet deploy late at night.
Queries that were instant at a thousand records crawl at a million. The code did not change. The business grew, and the design had no room for it.
The people who understood it moved on. What remains is a system everyone works around, and every workaround makes the next change harder.
Permissions checked in some places and not others, secrets in configuration files, no record of who changed what. It holds until the first security questionnaire or incident.
What we build
We choose the architecture the problem requires, not the one that looks impressive on a diagram. Often that is a well-organised modular monolith, sometimes a set of services. Either way, your business logic has one home and one owner.
REST and GraphQL APIs built to a written contract for your own apps, your partners and third parties, and versioned so nobody’s integration breaks without warning.
The rules that make your business yours, modelled once and in one place, so pricing, approvals and permissions behave the same in every application.
Schemas, migrations and data pipelines that keep one trustworthy version of the numbers, and still perform when the tables are a hundred times bigger.
Sign-in, single sign-on and role-based permissions, checked where the data is read rather than only at the front door.
Checkout, subscriptions, invoicing and reconciliation with Stripe or your provider, built so a retried request never charges anyone twice.
Queues, scheduled jobs and events for everything that should not keep a user waiting, with clear rules for what happens when a job fails.
The layer behind AI features: model APIs, retrieval, vector search, permissions and cost controls, engineered as software rather than a demo.
The tenancy, isolation and per-customer configuration a SaaS product needs to serve its hundredth customer, not just its first.
Moving a legacy backend forward without a big-bang rewrite: tests around what exists, then one capability at a time behind a stable interface.
The system is scalable for future efforts. It’s been a considerable upgrade for us. Their team did an excellent job implementing changes and suggesting how we can continue to make changes and the approaches we can take in the future.
Architecture
Each of these choices shapes what the system costs to run, how quickly it can change and how it behaves under pressure. We make them deliberately, write down why, and choose the simplest option that reliably handles the problem.
For most teams, a well-organised monolith with clear internal boundaries. Services earn their cost when separate teams or very different scaling needs demand them. Split too early and you distribute the difficulty instead of removing it.
Anything a user does not need to wait for moves to a queue: emails, exports, imports and third-party calls. Requests stay fast, and a slow partner cannot hold your product hostage.
Relational by default, because most business data is relational and consistency matters. Document, search or vector stores are added for a specific job, not as the starting point.
When several systems must react to the same thing, an order placed or a payment settled, events keep them in step without wiring each one to every other.
A cache makes the common case fast and the rare case confusing. We decide what may be slightly stale, for how long and how it is cleared before adding one.
Full-text search, filtering and relevance ranking work better in a dedicated search index than in clever database queries, once the data is large enough to need it.
Live updates and notifications are worth the extra moving parts when people act on them in the moment. Elsewhere a refresh is fine, and cheaper to run.
An API is a promise to everyone who integrates with it. We design it first, version it, document it and test that promise automatically on every change.
For each piece of data: which system owns it, whether it must be correct instantly or can catch up in seconds, and how disagreements are found and fixed.
Reliability
A backend is not good because it works when everything goes right. It is good because it behaves predictably when something goes wrong: a partner times out, a job runs twice, a server has a bad afternoon. These are the practices we build in, and then demonstrate to you rather than ask you to trust.
Timeouts, retries with backoff and circuit breakers on every external call, so one slow dependency cannot take the whole product down with it.
Retried requests carry a key and are safely deduplicated. A network timeout cannot charge a customer twice, whatever the client does.
When a non-essential part fails, the rest keeps working. Recommendations can disappear for an hour. Checkout cannot.
Structured logs, metrics and traces across every service, so an incident becomes a short investigation rather than a lost afternoon.
We page on the error rates and response times customers feel, not on CPU. Alerts nobody can act on get ignored, and then the real one does too.
Backups are restored on a schedule and the recovery plan is written down and tested. A backup nobody has restored is not a backup, it is a hope.
Security
Every control below exists because of a specific way businesses lose data, money or trust. We decide them at the start, when they are cheap, and we can show you each one working.
| Control | What we build | What it protects you from |
|---|---|---|
| Authentication | Sign-in, single sign-on and multi-factor authentication through proven identity providers, never a home-made password system. | Account takeover and stolen credentials being reused. |
| Authorisation | Role-based access, checked where the data is read rather than only at the route. | One customer seeing another customer’s data. |
| Data isolation | Tenant and record-level isolation, enforced by the data layer itself. | A single bug exposing everyone’s records. |
| Secrets | Keys and credentials in a managed secrets store, rotated, and never in code. | A leaked repository turning into a breach. |
| Encryption | Encryption in transit and at rest, and field-level encryption for the most sensitive data. | Intercepted or stolen data being readable. |
| Input validation | Every request checked against its contract before it reaches business logic. | Injection attacks and corrupted records. |
| Rate limiting | Limits per user and per client on every public endpoint. | Abuse, scraping and runaway integrations. |
| Secure integrations | Signed webhooks, scoped credentials and verified callers for every connected system. | A partner’s compromise becoming yours. |
| Audit trails | A record of who did what and when, kept as long as your obligations require. | Being unable to answer a customer or regulator after an incident. |
| Least privilege | Services, jobs and people get only the access their work needs. | One compromised component reaching everything. |
Performance and scale
It is a business property, not a benchmark screenshot. What matters is how the system behaves for your users, with your data, on your busiest day, so we agree targets for each system and measure them in production.
AI-ready backends
An AI feature needs everything any other feature needs, APIs, permissions, data, queues, monitoring, failure handling, security and cost controls, plus a few things of its own. We build that layer, and we run it in our own product, BotUp.
Calls to hosted or self-hosted models behind one interface, so a price change or a better model is a configuration change rather than a rewrite.
RAG pipelines, embeddings and vector search over your own data, with the permissions of the person asking applied to every result.
Agents that act in your systems only through declared permissions, with spending caps and a human approval step for anything consequential.
A test set for model behaviour, run on every change, so you know whether a prompt or model update made things better or worse.
Token and cost tracking per request, per customer and per feature, with limits that stop a runaway workload before the bill does.
Every model call logged with its inputs, sources, cost and outcome, so an answer can be explained to a customer, a regulator or your own team.
When to bring us in
Most teams call us at one of these moments. None of them automatically means a rewrite, and if a smaller fix gets you there, we will say so.
How we ship it faster
Backend work has a very high ratio of necessary, repetitive code to genuinely difficult decisions. Endpoint scaffolding, validation, serialisers, migrations, integration test suites, fixtures and client libraries are all patterned work that AI tooling drafts quickly and our engineers review. We put the time saved into the decisions that actually determine whether the system holds: transaction boundaries, failure modes, the data model, and what the system does when a dependency stops answering. AI accelerates the work. Our engineers stay accountable for the decisions and the software that ships.
An indicative comparison, not a quote or a guarantee. The gain depends on your data volumes, the third parties you integrate with and how much existing code has to be understood first. We estimate every project individually and put scope, timeline and price in writing, with a like-for-like comparison against conventional delivery, before you commit.
Why Brilliant Systems
The goal is not the most sophisticated backend. It is one your business can depend on and your team can keep changing for years.
The person who designs your backend understands the problem from the first conversation and stays through the build.
The decisions that are expensive to reverse are made deliberately, written down with their reasoning and reviewed with you before code depends on them.
AI tooling drafts the repetitive work so delivery is faster. Our engineers review every line and remain accountable for what ships.
Controls are part of the design from the first week, not a checklist in the final sprint.
We optimise for the second year as much as launch day: tests, documentation and boundaries that make the next feature easier, not harder.
Questions we get asked
We start from your team and your workload, not from fashion. For most products a well-organised modular monolith is faster to build, cheaper to run and easier to change. We split out a service when a separate team needs to own it, or when one part genuinely has to scale differently from the rest, and we write down why.
Yes, and usually without a rewrite. We put tests and monitoring around what exists so its real behaviour is visible, then replace one capability at a time behind a stable interface. Systems that survived a decade encode business rules nobody wrote down, and a big-bang rewrite tends to lose them.
Yes. We can take a defined part of the backend while your team continues on the product, or embed senior engineers alongside them. Either way the code, conventions and documentation are yours and written so your people can carry them on.
Yes, and it is a common starting point. We design the API around what the front end actually needs, so a mobile app on a poor connection is not making ten calls where one would do, and we version it so the apps already in people’s pockets keep working.
Yes. Migrations are rehearsed against a copy of production, run without a maintenance window where possible, and for anything financial or regulated we run old and new side by side and reconcile the results before anyone relies on the new one.
Usually, without replacing it. We measure first, because the cause is rarely where people expect: a handful of queries, a missing index, work that should be in a queue. We design so the next order of magnitude is affordable, and tell you where the ceiling is and what it would take to raise it.
Least privilege by default, secrets in a managed store, dependency scanning in the pipeline, and authorisation checked at the data layer rather than only at the route. For regulated work we build the audit evidence as we go, so it exists before anyone asks for it.
Yes. We connect AI features to the data and permissions you already have, behind one interface so models can be swapped, with cost limits, logging and a human approval step where the stakes call for one. It is the same engineering we use in our own AI product, BotUp.
With targets agreed for each system, tracing and structured logs across every service, and alerts that fire on what customers feel rather than on server metrics. Every alert comes with a runbook, so whoever is on call knows what to do at three in the morning.
Yes, either as continued development or as a defined support arrangement with 24/7 coverage. Retained work has no minimum term and thirty days’ notice, and support comes with the runbooks and handover so you are never dependent on us.
It depends on the integrations, the data volumes and how much existing code has to be understood before it can change, so we do not publish a price list. Within a week of our first call you get a written approach with a cost and time range and the assumptions behind it, which becomes a fixed proposal when you are ready.
You do. Repositories, cloud accounts and infrastructure definitions are in your name from the first commit, and nothing we build requires us to stay.
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