Sourcegraph is an excellent code search tool. You type a query, it finds matching code across your repositories. Fast, precise, and scalable.
But code search answers "where is this code?" It doesn't answer the questions developers actually need:
These are code intelligence questions, not code search questions.
Level 1: Code Search (Sourcegraph, grep) Find code by pattern. "Show me all uses of validateSession." Value: saves 5 minutes of manual searching.
Level 2: Code Navigation (IDE, Sourcegraph with intelligence) Jump to definitions, find references, see type hierarchies. Value: saves 10-15 minutes of manual tracing.
Level 3: Code Intelligence (Glue) Understand features, trace dependencies, surface history, map ownership, plan changes. Value: saves 30-90 minutes per ticket in context acquisition.
Most teams have Level 1 and 2 covered. Level 3 is where the Understanding Tax lives.
Search tells you: "validateSession is in auth/sessionService.ts." Intelligence tells you: "validateSession is part of the Authentication feature (14 files), which depends on the Redis Cache feature and is depended on by the Billing feature. Last modified in PR #847, which fixed a session leak."
Search tells you: "validateSession is called in 7 files." Intelligence tells you: "Changing validateSession affects the auth middleware, API guard, WebSocket handler (caution: hardcoded timeout assumption), billing webhook, and 3 test files. The WebSocket handler has caused issues with session changes before (PR #612, reverted)."
Search tells you: nothing about history. Intelligence tells you: "This function has been modified 12 times. The most significant change was PR #847 (session leak fix by Sarah). Mike has reviewed the most PRs in this area. The last 2 changes both required follow-up fixes for the WebSocket handler."
Use Sourcegraph when: you know what you're looking for and need to find it fast. "Where is the Stripe webhook handler?" → instant answer.
Use Glue when: you need to understand before you build. "I have a ticket to refactor the payment flow. What files are involved, what depends on them, what past issues exist, and what's my safest approach?" → comprehensive intelligence.
They're complementary. Sourcegraph is a flashlight. Glue is a map.
Code search answers "where?" Code intelligence answers "why?" and "what if?" The difference is the Understanding Tax — search saves 5 minutes of grepping, intelligence saves 30-90 minutes of context gathering.
For the full competitive landscape, read Glue vs CodeSee vs Sourcegraph: Code Intelligence Compared.
Glue provides pre-code intelligence — the Level 3 and 4 capabilities that search tools can't reach. Feature boundaries, blast radius, tribal knowledge, and build plans from tickets.