Azure Cosmos DB development services for applications that need sub-10ms reads across continents, multi-model flexibility, and the elastic scale that relational databases can't match. Data models designed for your query patterns, not forced into a relational shape. We build on Cosmos DB with the cost discipline that turns a powerful database into a sustainable one.
Why Entalogics for Cosmos DB
The Cosmos DB accounts we audit always have the same problems — a partition key chosen by guessing, cross-partition queries on every hot path, default indexing policy burning RUs on fields nobody queries, and a monthly bill that climbs 30% without traffic growing at all. Cosmos DB is powerful. Most implementations pay for that power without using it.
A bad partition key creates hot partitions that consume 80% of your RUs while the rest sit idle. We model your access patterns before provisioning and choose partition keys that distribute reads and writes evenly. The difference between a $500/mo and $5,000/mo Cosmos bill is usually the partition key.
Cosmos DB is not a relational database. Joins are expensive. Cross-partition queries are expensive. We model documents around how your application reads data — embedding related data, using change feed for materialised views, and keeping every hot-path query partition-aligned.
The default policy indexes every property — burning RUs on every write. We define indexing policies that include only the fields your queries actually filter on. Write-heavy workloads see 40–60% RU reduction from this change alone.
Autoscale for variable traffic that spikes unpredictably. Provisioned throughput for stable workloads with known patterns. Serverless for development and low-traffic apps. Each tier chosen by measurement — not by default.
When Cosmos DB, when not
Cosmos DB excels at global distribution, elastic scale, and sub-10ms latency. It also charges per request unit and punishes bad data models harder than any relational database. We'll tell you on the first call if Cosmos DB fits.
PICK COSMOS DB WHEN
CONSIDER ALTERNATIVES WHEN
WE SAY NO WHEN
What we build on Cosmos DB
The shapes of Cosmos DB development we deliver most. Each modelled for query patterns and cost-optimised from day one.
E-commerce, gaming, social — high-throughput read/write with sub-10ms latency. Documents modelled around access patterns, not entity relationships.
Device telemetry ingestion at millions of events per second. Hierarchical partition keys combining device ID and date. TTL for automatic data expiration. Change feed for real-time analytics.
Active-active multi-region writes with conflict resolution. Users in Tokyo, London, and New York all get sub-10ms reads from their local replica.
Existing MongoDB workloads running on Cosmos DB's managed infrastructure. Zero code changes. Global distribution and elastic scale without managing replica sets.
Existing accounts with runaway costs. Partition key analysis, indexing policy tuning, throughput right-sizing, and change feed for materialised views that eliminate cross-partition queries.
SQL Server or PostgreSQL data modelled for Cosmos DB. Documents denormalised around query patterns. Change feed replacing triggers. Migration with performance validation.
The playbook
Cosmos DB patterns from real production deployments — not quickstart tutorials.
P01
Access patterns documented. Read/write ratios measured. Partition key chosen for even distribution and query alignment. Never chosen by field name alone.
P02
Only the fields your queries filter on are indexed. Composite indexes for ORDER BY queries. Spatial indexes only where geo-queries exist. Default policy replaced on day one.
P03
Write-optimised container plus change-feed-projected read containers. Every query partition-aligned. Cross-partition fan-out eliminated from hot paths.
P04
Tenant ID as the first level, entity type as the second. Data isolated per tenant. Queries scoped to a single logical partition. No cross-partition reads for tenant-specific data.
P05
Autoscale with max RU/s set to a known ceiling. Budget alerts in Azure Cost Management. No bill surprises from a traffic spike that provisioned 100,000 RU/s permanently.
P06
Bulk operations for high-throughput ingestion. Transactional batch for multi-document atomicity within a partition. SDK configured with direct mode and TCP for lowest latency.
Signature case
A B2C e-commerce platform on Cosmos DB — monthly bill at $8,200, single partition absorbing 78% of traffic, cross-partition queries on the product listing page, and default indexing policy burning RUs on 40 unused fields. Remodelled the partition key, custom indexing policy, change feed for materialised product views, and autoscale with budget caps in 6 weeks. Monthly bill dropped to $3,100. Latency unchanged at 7ms.
Before
$8,200/mo · hot partition at 78% · cross-partition product queries · default indexing · no autoscale cap
After
$3,100/mo · even distribution · partition-aligned queries · custom indexing · autoscale with cap
Engagement shape
A typical Cosmos DB engagement. We model and deploy container by container — the current data stays live while we work.
Two senior Cosmos DB engineers. Partition key analysis, RU consumption profiling, indexing policy review, cost breakdown. A ranked, dollarized RFC.
Access patterns modelled, partition keys chosen, indexing policy defined, first container deployed with SDK integration. Real RU consumption measured.
Each container modelled, migrated, and validated. Change feed wired for materialised views. Autoscale configured. Your application keeps running.
Cost dashboard live. Indexing policies tuned. Runbook handed to your team — or we stay on retainer.
Stack
Our default Cosmos DB development stack — picked for production.
Engagement
No hourly retainer that bills for "thinking time." Pick a lane that matches your stage; everything is fixed-quote or transparently rated.
A defined scope, a fixed price, a senior-only team. From data modelling to production in 6–12 weeks.
$15k–$30k
FIXED SCOPE
Embedded engineers in your team. Senior data architects specialising in Cosmos DB. Pause, resize, end with 30 days' notice.
$5k / eng / mo
PER ENGINEER
A long-term partner for data-intensive applications — cost optimisation, global distribution architecture, migration strategy, hiring help.
custom
PROCUREMENT-FRIENDLY
Founder-direct
Thirty minutes with the founder. We'll bring a senior Cosmos DB engineer, the relevant playbook, and a candid read on whether Cosmos DB is the right database — or whether Azure SQL, PostgreSQL, or DynamoDB fits your workload better.
