--- title: CTO's Rule: Relational DBs First, Then Specialized Stores description: A practical rule of thumb for database architecture: start with a relational database as your system of record for core business entities like customers,... canonical: https://daily.dev/posts/cto-s-rule-relational-dbs-first-then-specialized-stores-lvn3dy6dt twitter:card: summary_large_image twitter:site: @dailydotdev og:type: website og:site_name: daily.dev og:title: CTO's Rule: Relational DBs First, Then Specialized Stores | daily.dev og:description: A practical rule of thumb for database architecture: start with a relational database as your system of record for core business entities like customers,... og:url: https://daily.dev/posts/cto-s-rule-relational-dbs-first-then-specialized-stores-lvn3dy6dt og:image: https://api.daily.dev/og/posts/LVn3DY6DT.png og:image:alt: CTO's Rule: Relational DBs First, Then Specialized Stores og:image:width: 1200 og:image:height: 630 og:locale: en --- > ## Documentation Index > Fetch the complete documentation index at: https://daily.dev/llms.txt > Use this file to discover all available pages before exploring further. # CTO's Rule: Relational DBs First, Then Specialized Stores **[The Serious CTO](https://daily.dev/sources/seriouscto)** · 1 min read · 0 upvotes · 1 comments ## Summary A practical rule of thumb for database architecture: start with a relational database as your system of record for core business entities like customers, accounts, permissions, and invoices. Then layer in specialized stores only for specific needs — Redis for caching/coordination, search infrastructure for search, a data warehouse for analytics, object storage for blobs, document stores for specific aggregates, and DynamoDB for access-pattern-driven workloads. This approach is described as healthy polyglot persistence, where the relational DB holds the single source of truth and derived systems serve targeted purposes. ## Full article daily.dev links to this article rather than hosting it. Read it at the original source: ## Questions this post answers ### When should I use a relational database versus a specialized database like DynamoDB or a document store? Start with a relational database as the system of record whenever the product involves customers, accounts, permissions, subscriptions, invoices, approvals, audit trails, workflows, or reporting, unless there is a concrete reason not to. Add specialized stores afterward for specific needs: Redis for caching and coordination, search engines for search, a warehouse for analytics, object storage for blobs, document stores for a specific aggregate, and DynamoDB for a known access-pattern-driven workload. _daily.dev surfaces database architecture guidance for engineers weighing relational versus specialized storage choices._ ### What is polyglot persistence and how should derived data stores fit into a system's architecture? Polyglot persistence means using multiple types of databases together, each suited to a specific need, while a relational database remains the system of record. Derived systems like caches, search indexes, warehouses, and document stores exist to serve specific needs rather than to replace the source of truth; the underlying principle is that these derived systems only serve specific, targeted purposes. _engineers designing multi-database systems can track architecture patterns like this on daily.dev._ ## Community discussion Top comments from developers on daily.dev. **@trevorsuna** · 0 upvotes > Starting relational-first also keeps the cost of early uncertainty low. Specialized stores shine when the access pattern is proven, but they add synchronization, recovery, and operational semantics immediately. Treating them as derived systems makes both failure handling and eventual-consistency tradeoffs much easier to explain. ## Similar posts on daily.dev - [How to Choose a Database for Your Next Project](https://daily.dev/posts/how-to-choose-a-database-for-your-next-project-cvd34xwxa) · BigData Boutique blog · 2 upvotes · 0 comments - [Why ‘Store Together, Access Together’ Matters for Your Database](https://daily.dev/posts/why-store-together-access-together-matters-for-your-database-beaa6wgn4) · The New Stack · 0 upvotes · 0 comments - [What Does a Database for SSDs Look Like?](https://daily.dev/posts/what-does-a-database-for-ssds-look-like--vim9utzwe) · Hacker News · 2 upvotes · 0 comments --- Tags: [#career](https://daily.dev/tags/career), [#architecture](https://daily.dev/tags/architecture), [#backend](https://daily.dev/tags/backend) [View this post on daily.dev](https://daily.dev/posts/cto-s-rule-relational-dbs-first-then-specialized-stores-lvn3dy6dt) ```json {"@context":"https://schema.org","@graph":[{"@type":"Organization","@id":"https://daily.dev/#organization","name":"daily.dev","url":"https://daily.dev","logo":{"@type":"ImageObject","url":"https://daily.dev/apple-touch-icon.png","width":180,"height":180},"sameAs":["https://twitter.com/dailydotdev","https://github.com/dailydotdev","https://www.linkedin.com/company/daily-dev-ltd"]},{"@type":"WebSite","@id":"https://daily.dev/#website","url":"https://daily.dev","name":"daily.dev","publisher":{"@id":"https://daily.dev/#organization"},"potentialAction":{"@type":"SearchAction","target":{"@type":"EntryPoint","urlTemplate":"https://daily.dev/search?q={search_term_string}"},"query-input":"required name=search_term_string"}}]} {"@context":"https://schema.org","@type":"TechArticle","headline":"CTO's Rule: Relational DBs First, Then Specialized Stores","url":"https://daily.dev/posts/cto-s-rule-relational-dbs-first-then-specialized-stores-lvn3dy6dt","mainEntityOfPage":{"@type":"WebPage","@id":"https://daily.dev/posts/cto-s-rule-relational-dbs-first-then-specialized-stores-lvn3dy6dt"},"datePublished":"2026-08-10T19:17:24.218Z","dateModified":"2026-10-15T02:22:56.644Z","description":"A practical rule of thumb for database architecture: start with a relational database as your system of record for core business entities like customers,...","image":"https://i.ytimg.com/vi/mZ4ECm2LbuE/sddefault.jpg","thumbnailUrl":"https://i.ytimg.com/vi/mZ4ECm2LbuE/sddefault.jpg","isAccessibleForFree":true,"articleSection":"The Serious CTO","inLanguage":"en","publisher":{"@type":"Organization","name":"daily.dev","url":"https://daily.dev","logo":{"@type":"ImageObject","url":"https://daily.dev/apple-touch-icon.png","width":180,"height":180}},"author":{"@type":"Organization","name":"The Serious CTO","logo":"https://media.daily.dev/image/upload/s--dry9Wxi8--/f_auto/v1710012378/logos/seriouscto","url":"https://daily.dev/sources/seriouscto"},"commentCount":1,"discussionUrl":"https://daily.dev/posts/cto-s-rule-relational-dbs-first-then-specialized-stores-lvn3dy6dt","interactionStatistic":[{"@type":"InteractionCounter","interactionType":{"@type":"LikeAction"},"userInteractionCount":0},{"@type":"InteractionCounter","interactionType":{"@type":"CommentAction"},"userInteractionCount":1}],"keywords":"career,architecture,backend","timeRequired":"PT1M","video":{"@type":"VideoObject","name":"CTO's Rule: Relational DBs First, Then Specialized Stores","description":"A practical rule of thumb for database architecture: start with a relational database as your system of record for core business entities like customers,...","thumbnailUrl":"https://i.ytimg.com/vi/mZ4ECm2LbuE/sddefault.jpg","uploadDate":"2026-08-10T19:17:24.218Z","duration":"PT1M","url":"https://api.daily.dev/r/LVn3DY6DT","embedUrl":"https://www.youtube.com/embed/mZ4ECm2LbuE"}} {"@context":"https://schema.org","@type":"BreadcrumbList","itemListElement":[{"@type":"ListItem","position":1,"name":"Home","item":"https://daily.dev"},{"@type":"ListItem","position":2,"name":"The Serious CTO","item":"https://daily.dev/sources/seriouscto"},{"@type":"ListItem","position":3,"name":"CTO's Rule: Relational DBs First, Then Specialized Stores"}]} {"@context":"https://schema.org","@type":"WebPage","@id":"https://daily.dev/posts/cto-s-rule-relational-dbs-first-then-specialized-stores-lvn3dy6dt","comment":[{"@type":"Comment","text":"Starting relational-first also keeps the cost of early uncertainty low. 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