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Delivery usually slows down in the contracts behind the UI, not in the UI itself.

API & Backend

API and backend engineering for teams that need clear system contracts before product work can move faster.

API and backend engineering for products that need cleaner contracts, steadier integrations, and less hidden operational risk.

We design and build API layers, backend services, integrations, and background processing for products that need dependable behaviour behind the interface.

Where this usually starts to hurt

We usually step in when frontend or mobile teams are blocked by unstable contracts, unclear system boundaries, or brittle integrations.

Where we can take responsibility

  • Contract design: Endpoint design, payload clarity, auth boundaries, and the interfaces frontend or mobile teams build against.
  • Integrations and background processing: Third-party systems, background processing, queues, adapters, and system logic behind the product.
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In brief

We usually start with the contracts and integrations creating the most drag, then clean up or build the backend layer around them.

1 contract layer

clean enough for frontend and mobile teams to build against with confidence

3 edges

contracts, integrations, and monitoring treated as one backend system

less drag

fewer hidden assumptions leaking into each release

Direct answer

API and backend engineering for products that need cleaner contracts, steadier integrations, and less hidden operational risk.

Key takeaways

  • Direct answer: API and backend engineering for products that need cleaner contracts, steadier integrations, and less hidden operational risk.
  • Typical output: API contracts: Clear contracts and backend endpoints that product teams can build against with fewer assumptions and less churn.
  • Best fit: The product is already moving, but backend uncertainty is slowing down every feature stream.
  • First weeks outcome: The product surface gets cleaner contracts to build against.
  • How Mijoo starts: Mijoo usually opens this kind of work with Map the system boundaries: We identify the contracts, dependencies, and integration points where the current setup is creating drag.

How we usually open the work

Map the system boundaries

We identify the contracts, dependencies, and integration points where the current setup is creating drag.

What the work typically leaves behind

  • API contracts: Clear contracts and backend endpoints that product teams can build against with fewer assumptions and less churn.
  • Integration and background work: Scheduled work, adapters, data movement, and failure handling designed to support real business processes.

Where we step in

Where we step in

API and backend engineering for products that need cleaner contracts, steadier integrations, and less hidden operational risk.

We usually step in when frontend or mobile teams are blocked by unstable contracts, unclear system boundaries, or brittle integrations.

Why this matters now

Once a product depends on multiple systems, weak contracts and unclear operational boundaries leak into every release. The team feels it first as drag, then as mistrust.

What the work typically leaves behind

API contracts

Clear contracts and backend endpoints that product teams can build against with fewer assumptions and less churn.

Integration and background work

Scheduled work, adapters, data movement, and failure handling designed to support real business processes.

Operational clarity

Logging, monitoring, and support-friendly structure so the backend stays understandable after delivery.

Typical situations

01

Frontend is blocked by unclear contracts

Frontend or mobile teams keep waiting on changing payloads, missing endpoints, or ambiguous state transitions.

02

A new product needs solid backend foundations

The next build needs backend structure that is clean enough to support the phase after launch, not just a demo.

03

Integrations and background jobs are fragile

Jobs, integrations, and business processes have become too important to stay brittle and hard to debug.

Best fit

  • The product is already moving, but backend uncertainty is slowing down every feature stream.
  • Multiple systems or external services need to behave like one coherent platform.
  • The team needs cleaner contracts and less hidden operational complexity.

Not a fit

  • The real bottleneck is still product direction, not backend shape.
  • The team wants to keep undocumented coupling because it feels faster in the short term.
  • Nobody is willing to name failure modes or operational ownership clearly.

First weeks outcome

  • The product surface gets cleaner contracts to build against.
  • Integration risk becomes easier to see, isolate, and debug.
  • Operational handling starts moving from tribal knowledge into system design.

How the work unfolds

How the work unfolds

We usually start with the contracts and integrations creating the most drag, then clean up or build the backend layer around them.

01

Map the system boundaries

We identify the contracts, dependencies, and integration points where the current setup is creating drag.

02

Lock contracts and failure paths

We make payloads, status transitions, retries, and failure handling explicit before the backend surface grows further.

03

Build the backend layer

We implement or restructure the API, services, integrations, and background work the product depends on.

04

Stabilise operations

We add the visibility, failure handling, and support structure needed to keep the system usable after launch.

What we can own technically

What we can own technically

We design and build API layers, backend services, integrations, and background processing for products that need dependable behaviour behind the interface.

Contract design

Endpoint design, payload clarity, auth boundaries, and the interfaces frontend or mobile teams build against.

Integrations and background processing

Third-party systems, background processing, queues, adapters, and system logic behind the product.

Observability and support

Monitoring, logging, error paths, and the operational clarity needed to run the system without guesswork.

Technologies

The stack we most often use to get this kind of work into production cleanly

01

API foundation

  • Node.js
  • NestJS
  • Express.js
  • PostgreSQL
  • Redis
  • MongoDB
  • Elasticsearch

02

Data and processing

  • PostgreSQL
  • Redis
  • BullMQ
  • RabbitMQ
  • MongoDB
  • Elasticsearch

03

Integrations and operations

  • REST APIs
  • Webhooks
  • Docker
  • OpenTelemetry
  • OpenAI

Relevant work

Relevant work

We usually step in when frontend or mobile teams are blocked by unstable contracts, unclear system boundaries, or brittle integrations.

SalesMemo: product flows that depended on predictable backend state and dependable contracts.

Digitálny Súhlas: structured records with dependable status handling across multiple systems.

Product flow with predictable backend state.

SalesMemo

SalesMemo is a mobile-first iOS and Android product that converts voice notes after meetings into structured AI outputs. It helps sales teams generate summaries, tasks, and follow-up drafts in minutes instead of manually rebuilding context.

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Structured records with dependable status handling.

Digitálny Súhlas

Digitálny Súhlas is an electronic consent and signature platform for organizations that need legally safer, paperless consent collection. It supports both in-person kiosk signing and remote signing via secure online links.

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Questions before kickoff

Questions before kickoff

Open the contact form with the backend project type preselected.

Yes. The work can stay tightly bounded as long as the surrounding contract and operational edges are still made explicit.

Working through something similar?

Show us where we should step in

Send a short note about the product, its current stage, and the pressure that is slowing the next release down. We open the contact flow in the right context and keep the first step practical.

Open the contact form with the backend project type preselected.

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