Offline-First Apps with
Real-Time Truth.

Build experiences that feel instant—even when the network isn’t. We engineer local-first data layers and real-time sync engines with conflict resolution, durable writes, and observability.

Request Scoping

Works Offline

Live Updates

No Data Loss

Offline + Real-Time Systems Trusted in Production Workflows

0%
Lost Writes Target

Durable local commits before network calls.

<120ms
Local Read Latency

Instant UX from local state, not round-trips.

100%
Offline Continuity

Core flows keep working without connectivity.

$0.
Vendor Lock-In

Own the data model, sync logic, and transport.

Beyond the Realtime Demo.
Reliability Through Network Chaos.

Most apps fail when the network drops because they treat connectivity as guaranteed. We design durable local state, idempotent sync, and conflict resolution—so your product keeps moving on Day 2.

The Failure Pattern

What most “build teams” ship:

  • Online-Only Data Flows

    Writes depend on round-trips; users lose work when signal drops.

  • No Conflict Strategy

    Duplicate updates, overwrites, and silent divergence across devices.

  • Zero Sync Observability

    No replay, no tracing, no drift detection for data correctness.

The Coretus Standard

Offline-first + real-time, production-grade:

  • Local-First Writes

    Every action commits locally first; sync happens after—with retry and replay.

  • Sync + Conflict Resolution

    Idempotent operations, versioning, and reconciliation patterns to preserve truth.

  • Telemetry + Auditability

    Sync tracing, retries, failure reasons, and deterministic replay for correctness.

Instant UX. Correct Data. Always.

Strategic Capabilities.

From local state to real-time truth at scale.

Local-First Data Layer

Durable local writes, indexed reads, and fast UX even with zero connectivity.

  • Local Transactions
  • Optimistic UI

Sync Engine

Queue-based sync, retries, idempotent operations, and background reconciliation.

  • Retry + Backoff
  • Replayable Ops

Conflict Resolution

Deterministic reconciliation patterns to prevent overwrites and silent divergence.

  • Versioning
  • Merge Policies

Real-Time Updates

WebSockets/subscriptions/event streams that keep teams synchronized instantly.

  • Presence + Feeds
  • Low-Latency Push

Resilient Networking

Adaptive transport, batching, and edge-case handling for flaky mobile networks.

  • Batched Writes
  • Adaptive Polling

Sync Observability

Tracing, audit logs, failure reasons, and alerts for correctness at scale.

  • Sync Traces
  • Error Budgets
/// Offline-RT Stack

A Hardened Loop for
Local-First Sync.

Local Data Model

Durable State

Local transactions, indexed reads, and deterministic state updates that never depend on connectivity.

Optimistic UI
Local Transactions
Schema Evolution
LocalIndexedDurable

Sync Engine

Retry + Replay

Queued operations, idempotency, backoff, and replay so correctness survives mobile networks.

Idempotent Ops
Retry + Backoff
Deterministic Replay
QueueRetryReplay

Conflict Handling

Truth Preservation

Merge strategies, versioning, and guardrails to prevent overwrites and silent divergence.

Version Vectors
Merge Policies
Audit Trails
MergeVersionsPolicies

Real-Time + Observability

Ops Control

Streams, presence, and sync tracing so teams see what happened—and why—across devices.

Live Feeds + Presence
Sync Trace IDs
Error Budgets + Alerts
StreamsTracesAlerts
/// Offline-First Accelerator

Ship Offline-First.
Skip the Data Chaos.

We deploy the Coretus Sync Kernel™—a pre-hardened foundation for local-first storage, queued sync, conflict resolution, and telemetry.

Your teams focus on product flows and user adoption, not rebuilding data correctness.

4-8 Wk

Time-to-Reliability Saved

10x

Fewer Sync Failures Target

Built for retry/replay, conflict policies, and audit trails.
Sync Hardened

Network Reality

Drops • Retries • Latency • Multiple Devices

Coretus Sync Kernel v2.4

Local Store

  • • Txn
  • • Index

Sync Engine

  • • Queue
  • • Replay

Conflicts

  • • Merge
  • • Policy

Telemetry

  • • Trace
  • • Alerts
/// Pre-Configured Offline-RT Pods

Deploy Production-Ready Offline Squads.

Integrated delivery units specialized in local-first data, sync engines, and real-time reliability—so you ship once, not rework forever.

Offline-First Architect

Designs durable local data models, schema evolution, and fast UX under connectivity constraints.

Local TxnIndexingSchema

Sync & Conflict Lead

Builds reconciliation policies, versioning, and deterministic replay to preserve correctness across devices.

MergePoliciesReplay
99.9%
Sync Correctness Target
Reliability Validation Included

Squads arrive with retry/replay patterns, conflict policies, and sync telemetry—built-in from day one.

Real-Time Engineer

Streams, subscriptions, presence, and low-latency transport tuned for real-world networks.

StreamsPresenceTransport

Sync Ops Lead

Observability, traces, failure analytics, and alerting to keep correctness stable as you scale.

TracesAlertsBudgets
/// Architectural Integrity

The Offline-RT Blueprint.

Reliability is a loop: local commit, sync queue, reconcile, publish updates, and observe correctness.

01. Local Store

Transactions, indexing, and offline reads/writes that power instant UX.

Building Blocks:
Local Txn • Indexing • Schema

02. Sync Queue

Queued ops, retries, batching, and idempotency to survive mobile networks.

Building Blocks:
Queue • Backoff • Replay

03. Real-Time Channel

Push updates, presence, and subscriptions for low-latency collaboration.

Building Blocks:
Streams • Presence • Subscriptions
Live Truth

04. Correctness + Telemetry

Tracing, audits, drift signals, and alerting to keep data truthful at scale.

Building Blocks:
Trace IDs • Audit Logs • Alerts
Auditability
Local-First
Real-Time
/// Delivery Framework

The Road to Reliable Sync.

A phased model that prevents data chaos: local model, sync engine, conflict policies, then scale.

Phase 01

Data + UX Flow Audit

Define offline-critical flows, data model, sync boundaries, and correctness metrics.

Output: Offline Feasibility Blueprint
Phase 02

Local-First Foundation

Implement durable local writes, indexing, optimistic UI, and schema evolution strategy.

Output: Local Data Layer
Phase 03

Sync + Conflict Policies

Queue ops, idempotency, retries, reconciliation rules, and replay for correctness.

Output: Correctness Engine
Phase 04

Real-Time + Observability

Add live updates, presence, tracing, audits, and alerts to keep correctness stable as you scale.

Output: Production-Ready Offline-RT
/// Production Outcomes

Proven Offline-RT Outcomes.

Case Archives
0%
Lost Orders Target

Offline Field Ops for
High-Volume Workflows

Work orders failed in low-signal areas, causing lost updates and re-entry.

Delivered local-first writes + retry/replay sync with audit trails.

"Teams stopped losing work. Offline became the default, and sync just works in the background."

OP
Operations Lead
Field Services
2.8x
Collaboration Speed

Real-Time Collaboration for
Distributed Teams

Updates arrived late and conflicted across devices, creating duplicate actions.

Shipped presence + streams with deterministic reconciliation and telemetry-backed ops.

"Everyone sees the same truth instantly—no more guessing which device is correct."

RT
Product Owner
Collaboration Suite
/// Delivery Models

Offline-RT Partnership Models.

Choose the engagement aligned with delivery speed, correctness needs, and operational ownership.

Fast Delivery

Managed Offline-RT Squads

Embedded team specialized in local-first data, sync correctness, and real-time systems.

Velocity & Correctness
SQUAD SPECS
Strategic Advisory

Fractional Engineering CTO

Define offline-first architecture, sync strategy, correctness metrics, and rollout plan.

Strategy & Architecture
EXPLORE ADVISORY
Build-Operate-Transfer

Build-Operate-Transfer

We incubate your offline-first platform, stabilize it in production, then transfer ownership to your teams.

Platform Ownership
VIEW BOT MODEL
Scale Delivery

Offline-RT ODC

Your dedicated offline-first + real-time delivery center for continuous improvements and expansion.

Operational Scale
EXPLORE ODC
/// Trust & Controls

Governed
Data Correctness.

Offline-first systems must balance speed with correctness. We embed conflict policies, audit trails, and deterministic replay—so data remains trustworthy in production.

Deterministic Sync + Replay

Traceable operations with safe retries and replays for correctness.

Secure Local Storage

Encrypted-at-rest options and guarded data access patterns.

Audits + Observability

Trace IDs, audit logs, and alerting to catch regressions early.

Audit Logs

Traceable Ops

Security

Local Controls

Conflicts

Merge Policies

Telemetry

Sync Traces

/// Reliability Briefing

See the Offline-RT Stack.

A 100-second breakdown of local-first data, sync queues, conflict handling, and telemetry.

Coretus Offline-First & Real-Time Briefing
Reliability Lead
Principal Engineer
Offline Systems Lead
01:40 • OFFLINE MODE

Local-First

Instant UX from durable local state.

Sync Engine

Retry/replay correctness under chaos.

Conflicts

Deterministic merges, no silent divergence.

/// Offline-RT FAQs

Frequently Asked
Reliability Specs.

Service Identity
Offline-First & Real-Time Apps

Does the app work with no internet?

Yes. Core flows commit locally first; connectivity only affects background sync, not UX.

How do you handle retries safely?

We design idempotent operations, backoff policies, and deterministic replay with traceability.

What about conflicts across devices?

We implement merge policies (and when needed, CRDT-style patterns) to preserve truth.

Real-time updates at scale?

Yes. We design streams/subscriptions/presence with fallbacks and observability.

How do we monitor sync correctness?

Sync traces, failure reasons, audits, and alerting—so regressions get caught early.

Offline Feasibility?

We can deliver a rapid feasibility audit for your most critical offline flow and sync constraints.

Request Briefing

Ship Apps That Work Without Signal.

Most “real-time apps” are demos that collapse under flaky networks. We build offline-first, real-time products with durable local writes, sync engines, conflict resolution, and observability—so the UX stays fast and data stays correct.

Local-First Data Layer

Resilient Sync + Conflict Handling

Production Observability

Request Offline-First BriefingRequest Offline-First Briefing