SS-06 · Custom development

Custom development

We build software when your operations do not fit a SaaS. Microservices and DevOps when the problem justifies it. Fortnightly sprints with a live demo.

Cycle14-day sprint
StackTS · Python · Go · Rust
Modelfixed-scope or T&M

Not every process has a SaaS, and not every SaaS fits the real process. When an off-the-shelf tool falls short — because the flow is highly specific, because integration costs more than development, or because data cannot leave the client's environment — we build custom.

Current stack: TypeScript, Python, Go, Rust depending on the problem; React/Next/Nuxt/Svelte on the front end; Node/FastAPI/Spring/.NET on the back end; Postgres as the default database. Microservices only when the team and operations justify it; modular monolith when they do not.

What we deliver is a production system with documented code, tests, automated deployment, observability, and handover to the client's team. Not closed projects with opaque code.

L1Edge & CDN
  • Cloudflare
  • Vercel Edge
  • WAF
L2Front-end
  • Next.js
  • Nuxt
  • Svelte
  • React Native
L3API & services
  • Node · Fastify
  • FastAPI
  • Go
  • .NET 8
L4Data
  • Postgres
  • ClickHouse
  • Redis
  • S3
L5Platform
  • Kubernetes
  • Terraform
  • GitHub Actions
  • Grafana

The Custom development process.

The process · four stages
01

Discovery

Process mapping, SaaS vs custom decision, functional definition.

02

Technical design

Architecture, stack, data model, integrations.

03

Build

Fortnightly sprints with a live demo.

04

Handover

Documented code, tests, automated deployment.

What is included

What Custom development includes.

The operational detail: what we deliver as part of the engagement and what we keep active afterwards.

  • Web and internal applications

    Processes that do not fit a SaaS.

  • Mobile and hybrid

    React Native, Flutter, native Swift/Kotlin.

  • Microservices when applicable

    Not by default. Modular monolith when it works.

  • DevOps and CI/CD

    GitHub Actions, Docker, Kubernetes, Terraform.

  • Operational documentation

    What your team needs to operate.

  • Full handover

    Code, secrets, infra, runbooks. No black box.

Summum cluster

How it intersects with related services.

What is built runs in production. It integrates with cloud, security, and data services.

Frequently asked questions about Custom development.

Fixed scope or T&M?

Fixed scope when the scope is clear. T&M when there is iterative discovery.

What stack?

TS, Python, Go or Rust depending on the problem. React/Next/Nuxt on the front end; Node/FastAPI/Spring/.NET on the back end.

Is the code ours?

Yes. Repository in your organisation from day one.

Operations · open log

This is what a deployment sounds like.

What you see when a release goes to production. No surprises, no manual clicks.

~/summum · development
→ summum deploy --env prod --service api --tag v2.14.0
checking signing key… ok
✓ tests passed (1,241/1,241) in 3m 41s
✓ build signed · sha 9f3a82c
✓ canary 5% · 4m · p99 124ms · errors 0
✓ rollout completed in 4m 12s

→ summum status api.client.com
status                healthy
uptime                47d 09h 22m
replicas              3/3
p50 / p95 / p99       38ms / 89ms / 124ms
error rate (1h)       0.00%
Implementation notes

Implementation notes.

Post-mortems and technical notes from real projects.

2026-04 Fashion eCom · LCP

Notable latency reduction in 6 weeks

Images converted to AVIF, n+1 query fixed, CDN cache. Conversion improved in the quarter.

Resolved
2026-02 Industrial · custom ERP

Quote cycle, from days to hours

.NET module on top of CRM + legacy ERP. We kept the accounting SaaS.

Production
2025-12 Public sector

High-volume service migrated to the cloud with no downtime

Strangler-fig pattern over 22 weeks. Low RTO, tested on game day.

Migration