Keep every system. Retire the exports.

The seams are where it breaks

Every company runs systems bought at different times, by different people, for different reasons. The systems are rarely the problem. The joins are: data that disagrees, processes that pause until morning, and connectors that fail quietly until a customer calls to tell you.

• Two systems, two numbers, and a standing meeting to decide which one is right.
• Nothing is real time, because everything waits for the 2am job.
• One engineer understands the bridge. They are on holiday.
• Every new tool adds another bespoke connector nobody wants to own.

Integrations built to be handed over

We map how data actually moves — including the spreadsheets, the manual re-keying, and the script running on someone’s laptop — then design the smallest set of interfaces that make the whole thing coherent. Contracts first, so each system can change without breaking its neighbours.

• A data-flow map of what exists today, undocumented paths included
• Versioned interface contracts and schemas, one per system boundary
• Integrations with retries, idempotency keys, and a dead-letter queue you can replay
• Alerts wired to the failure modes that matter, so you hear it before your customer does
• A reconciliation view showing exactly where two systems disagree
• Runbooks written for whoever is on call, not for us

1. 01

   Trace

   Follow the data end to end and write down the real path — the one with the spreadsheet in it, not the architecture diagram from three years ago.

2. 02

   Contract

   Define what each system promises the others, version it, and put a test behind it. Changes stop being surprises.

3. 03

   Connect

   Build one flow at a time with failure handling as a feature, running alongside the old path until the numbers agree.

4. 04

   Observe

   Instrument everything, alert on drift, and hand over runbooks your team can act on without calling us.

We build the plumbing other people depend on. RedisOplog, @bluelibs/nova, @bluelibs/x, and @bluelibs/runner are used worldwide for realtime data and query performance at scale, with 1000+ GitHub stars between them. The same discipline shows up in client work: Fortune 500 delivery including StoneX Group, and a German legal tech platform where claims, foreclosure, and dunning workflows had to stay strictly isolated per tenant.

• Can you work with our legacy system?

  Yes. Legacy usually means load-bearing. We integrate around it and modernise only where there’s a reason beyond taste.

• Should we just buy an integration platform instead?

  Sometimes, and we’ll tell you when. Platforms handle common connectors well and hide business logic badly. If your rules live inside the integration, a drag-and-drop canvas becomes the least testable code you own.

• How do you avoid breaking production?

  One flow at a time, behind contracts, with the old path still running. We cut over when reconciliation shows the two agree, and not before.

• Who maintains it afterwards?

  Your team. Runbooks, monitoring, and contracts are built for that from the first week. We stay available; we don’t plan to be necessary.