Track 04 · Data Integration

Data Integration

The practice of combining data from many disparate sources — databases, apps, APIs, files and streams — into a unified, consistent view. It is the plumbing beneath every analytics dashboard, AI model and customer-360, and the discipline that turns silos into a single source of truth.

Read time ~18 min Level Foundational → Advanced For Data Engineers, Architects

What you'll be able to do

Learning outcomes for this track

  • Choose between ETL, ELT, streaming, CDC and virtualisation for a case
  • Build an idempotent, incremental ELT pipeline
  • Set up change data capture and stream it reliably
  • Orchestrate pipelines with retries, backfills and observability
  • Handle schema drift and enforce data contracts
  • Plan a career path and self-assess against a skill matrix

01 What it is

From many silos to one view

Definition

Data integration combines data from many disparate sources into a unified, consistent view — encompassing the movement, consolidation, transformation and delivery of data to its targets.

It matters because it powers everything downstream: analytics and BI, AI/ML and RAG, and customer or entity 360 views. Get it right and every team works from the same numbers; get it wrong and you reconcile spreadsheets forever. The central design choice is where and when transformation happens — before load (ETL) or after (ELT), in batch or in a stream.

02 Core concepts

The moving parts

  • ETL vs ELTtransform before load, or load raw and transform in the target. ELT is the cloud default.
  • Batch vs streamingperiodic bulk moves vs continuous, low-latency flow.
  • CDCchange data capture reads row-level changes from source logs for low-impact sync.
  • Pipeline & connectora source-to-target flow, and the pre-built adapter that taps a source.
  • Orchestrationscheduling, dependencies, retries and backfills across tasks.
  • Reverse ETLpushing warehouse data back into operational apps.
  • Data virtualisation / federationquerying sources in place, without copying.
  • iPaaS & EAIcloud integration platforms and app-to-app integration.

03 Patterns

Choose the pattern for the latency

ELT

Load raw, push transforms to the warehouse or lakehouse. The default for cloud analytics.

ETL

Heavy pre-load transforms. For legacy, compliance or limited-compute targets.

Streaming / event-driven

Sub-second latency for real-time apps, fraud and IoT.

CDC

Incremental sync from database logs — low-impact, near-real-time replication.

Data virtualisation

No movement — query sources in place for governed, ad-hoc access.

Replication

Full or incremental copies for DR, migration and offload.

Zero-copy sharing

Share data in place across accounts and clouds — no ETL, no egress.

Data mesh integration

Decentralised, domain-owned data products exchanged via contracts.

04 Key personas

Who integrates data

DE

Data Engineer

Builds and operates the pipelines and transformation models.

PipelinesPython
ID

Integration Developer

Implements source-to-target mappings and transforms.

Mappings
DA

Data Architect

Designs the integration and platform blueprint and standards.

Blueprint
DO

DataOps / Platform Engineer

Owns CI/CD, tooling and the reliability of the data infrastructure.

CI/CDReliability
AE

Analytics Engineer

Builds dbt-style transforms bridging raw data to BI.

dbt
IA

Integration Architect

Designs enterprise app, API and iPaaS integration.

APIsiPaaS
BA

Business Analyst

Owns requirements, mappings, quality rules and reconciliation.

STTMRecon
DG

Governance Lead

Ensures pipelines honour contracts, lineage and privacy.

Contracts

05 Methodology

Discover, move, model, monitor

01

Profile sources

Discover schema, volume, quality and keys before you move a single row.

02

Define targets & SLAs

Agree targets, freshness, SLOs and success metrics with consumers.

03

Choose the pattern

ETL, ELT, streaming or CDC — driven by latency and cost, not habit.

04

Ingest & land raw

Build connectors or CDC; land raw data before transforming it.

05

Transform & orchestrate

Model staging to curated; schedule with dependencies, retries and backfills.

06

Test & observe

Validate and reconcile; monitor freshness, volume and lineage; handle drift.

06 Best practices

What good looks like

Make pipelines idempotentA re-run yields the same result — safe retries, no duplicates.
Prefer incremental / CDCMove only what changed instead of full reloads.
Handle schema driftEvolve or alert automatically — never let a new column break the load.
Enforce data contractsAgree schema, quality and SLA between producers and consumers.
Check quality in-pipelineValidate as data flows, not in a report after the fact.
Decouple ingest from transformLand raw first; transform separately so failures isolate.
Add observabilityTrack freshness, volume, lineage and alerting — know before users do.
Apply DataOpsVersion control, tests, CI/CD and orchestration with retries; optimise cost.

08 In practice

Plumbing that moves the business

Integration is invisible when it works and catastrophic when it doesn't. Here's how enterprises apply it, what the analysts and platforms are doing, and how SCIKIQ delivers it.

Customer / entity 360

Merge CRM, transactional, support and web data into one governed profile for personalisation and retention.

Real-time analytics & fraud

Stream events with CDC so fraud scoring, pricing and inventory act on live data, not overnight batches.

Unified data for AI & RAG

Consolidate and govern data as the trusted foundation feeding ML, GenAI and retrieval.

Cloud & lakehouse migration

Move and re-platform legacy on-prem estates to cloud warehouses and lakehouses with minimal disruption.

Operational & regulatory reporting

Deliver consistent, reconciled data across finance, risk and compliance to shorten close cycles and audits.

Breaking silos post-M&A

Integrate acquired systems into one layer so merged entities report and operate on shared data.

What the leaders are doing

ELT on the lakehouse and open table formats now define the category — here's the signal from the standard, the analysts and the platforms.

DADAMAStandard · DMBOK

DMBOK2's Data Integration & Interoperability knowledge area defines the patterns — ETL, ELT, replication, virtualisation — and the governance around moving data.

GGartnerAnalyst

Publishes the annual Magic Quadrant for Data Integration Tools (2025) and frames five use cases from data engineering to real-time integration, converging with ingestion.

FForresterAnalyst

Its iPaaS and Streaming Data Platforms Waves (2025) track integration expanding into AI-driven business-process orchestration.

MMcKinseyAdvisory

Advises on data-architecture modernisation across five archetypes; the right one can roughly halve implementation time and cut costs ~20% in banking.

AAccentureAdvisory

Delivers cloud data migration and integration services with industrialised frameworks, often on partner platforms.

DDatabricksPlatform

GA'd Lakeflow (2025) — managed ingestion, declarative pipelines and orchestration — plus full Iceberg support and zero-copy Delta Sharing.

How SCIKIQ helps

SCIKIQ's Data Hub points at what you already run. Connect every source, move it with ELT, streaming or CDC, and land it in one governed layer ready for analytics and AI.

  • Connect any source across on-prem, hybrid and multi-cloud.
  • ELT, streaming and CDC from a single platform.
  • Governed ingestion — lineage, catalog and access as data lands.
  • Automatic schema-drift handling so pipelines don't silently break.
  • One governed, open-format layer for BI, ML and RAG.

09 Developer lab

Hands-on: ship a reliable pipeline

Engineer track

Do it
  1. Build an ELT pipeline: Airbyte extract/load plus dbt transforms.
  2. Set up CDC with Debezium into Kafka to a sink.
  3. Orchestrate a DAG with retries and backfill in Airflow or Dagster.
  4. Ingest an API in Python with dlt — auto schema, incremental.
  5. Implement a schema-drift handler and an idempotent merge.
# dlt: incremental, idempotent API ingestion
import dlt
@dlt.resource(primary_key="id", write_disposition="merge")
def orders(updated_at=dlt.sources.incremental("updated_at")):
    yield get_orders(since=updated_at.last_value)

pipeline = dlt.pipeline(destination="snowflake")
pipeline.run(orders)

Skills you build

Outcome
  1. Standing up an end-to-end ELT pipeline.
  2. Streaming change data capture reliably.
  3. Orchestrating with retries and backfills.
  4. Writing Python-native incremental ingestion.
  5. Surviving schema drift without breakage.

Reference implementation

ingest → capture → transform
dags/orders_elt.pyApache Airflow
# Land raw, then transform — 3 retries and backfill built in
from airflow.decorators import dag, task
from pendulum import datetime

@dag(schedule="@hourly", start_date=datetime(2026, 1, 1),
     catchup=True, default_args={"retries": 3})
def orders_elt():
    @task
    def extract_load():   ...   # dlt / Airbyte lands raw rows idempotently
    @task
    def transform():      ...   # dbt build --select stg_orders+
    extract_load() >> transform()

orders_elt()
orders-cdc.jsonDebezium · CDC
// Stream row-level changes from Postgres into Kafka
{
  "name": "orders-cdc",
  "config": {
    "connector.class": "io.debezium.connector.postgresql.PostgresConnector",
    "database.hostname": "db.internal",
    "table.include.list": "public.orders",
    "plugin.name":  "pgoutput",
    "topic.prefix": "cdc",
    "snapshot.mode": "initial"
  }
}
models/staging/stg_orders.sqldbt · incremental
-- Idempotent, incremental merge — safe to re-run any time
{{ config(materialized='incremental', unique_key='order_id',
          incremental_strategy='merge') }}

select order_id, customer_id, amount, updated_at
from {{ source('cdc', 'orders') }}
{% if is_incremental() %}
  where updated_at > (select max(updated_at) from {{ this }})
{% endif %}

A complete real-time slice: Airflow orchestrates with retries, Debezium captures every change from the source, and the dbt model merges incrementally — re-runnable, deduplicated and cheap.

10 Analyst lab

Hands-on: specify the integration

Analyst track

Do it
  1. Author a source-to-target mapping (STTM) document.
  2. Perform data profiling — nulls, cardinality, ranges, keys.
  3. Define integration SLAs and data-quality rules.
  4. Gather requirements for a customer 360 view.
  5. Run reconciliation testing — source vs target counts and sums.

Deliverables

Outcome
  1. A complete STTM engineering can build from.
  2. A profiling report flagging source risks.
  3. Agreed SLAs and quality rules.
  4. A 360 requirements spec.
  5. A reconciliation result proving parity.

11 Career path

From ETL developer to head of platform

Data engineering is among the most in-demand data roles. Bands are indicative US figures and vary by market.

01
ETL Developer / Junior EngineerEntry
SQL, one ETL tool, basic scripting.
~$85–120k
02
Data EngineerPractitioner
Python, pipelines, orchestration, a cloud warehouse.
~$120–160k
03
Senior / Lead Data EngineerSenior
Streaming, CDC, architecture, DataOps, mentoring.
~$160–210k
04
Data / Integration ArchitectLeadership
Platform strategy, governance and integration patterns.
~$180–230k
05
Principal / Head of Data PlatformExecutive
Org-wide strategy, standards and platform vision.
$200k+

12 Skill matrix

Rate yourself, then level up

Find your current row and aim one column right.

SkillBeginnerIntermediateAdvanced
SQLJoins and aggregations.Window functions and CTEs.Query tuning and performance.
PythonWrites scripts.Builds dlt / pandas pipelines.Frameworks and testing at scale.
ETL / ELT toolsRuns a managed connector.Builds custom extract/load.Designs the ingestion platform.
OrchestrationRuns a scheduled DAG.Builds DAGs with retries/backfill.Designs orchestration standards.
Streaming / KafkaConsumes a topic.Builds a streaming job.Designs exactly-once pipelines.
CDCUnderstands log-based CDC.Runs Debezium into a sink.Operates CDC at scale.
Cloud data platformsLoads to a warehouse.Models on Snowflake / Databricks.Optimises cost and performance.
ObservabilityReads pipeline logs.Adds freshness/volume checks.Builds lineage-aware alerting.

13 Glossary

Terms worth knowing

ETL
Extract, transform, then load.
ELT
Load raw, then transform in the target.
CDC
Change data capture — capturing source row-level changes.
Idempotency
A re-run yields the same result.
Orchestration
Scheduling and dependency management of tasks.
Connector
A pre-built source or target adapter.
Reverse ETL
Warehouse data pushed back to operational apps.
Data virtualisation
Querying sources in place without copying.
Lakehouse
Warehouse features on open lake storage.
Open table format
Iceberg / Delta / Hudi metadata over data files.
Schema drift
Source structure changing over time.
Backfill
Loading historical or previously missed data.

14 Test yourself

Check your understanding

Four quick questions — instant feedback, nothing saved, no sign-up.

Q1What is the key difference between ETL and ELT?

ELT is the cloud/lakehouse default. Land raw data in the warehouse, then transform it there with the platform's compute.

Q2Change Data Capture (CDC) is used to…

CDC (e.g. Debezium) enables near-real-time replication. It reads the database log instead of re-scanning whole tables.

Q3Making a pipeline "idempotent" means…

Idempotency is what makes retries and backfills safe. A merge on a unique key is the classic pattern.

Q4Which are open table formats that power the lakehouse?

Open table formats add warehouse features over lake files. ACID transactions, schema evolution and time travel across engines.