--- title: Uber open-sources SubmitQueue, Modal rewrites I/O plane... description: Uber open-sourced SubmitQueue, a Go-based speculative merge queue that validates multiple changes in parallel against predicted future HEAD states — a direct... canonical: https://daily.dev/posts/uber-open-sources-submitqueue-modal-rewrites-i-o-plane-in-go-mgakttc51 twitter:card: summary_large_image twitter:site: @dailydotdev og:type: website og:site_name: daily.dev og:title: Uber open-sources SubmitQueue, Modal rewrites I/O plane in Go | daily.dev og:description: Uber open-sourced SubmitQueue, a Go-based speculative merge queue that validates multiple changes in parallel against predicted future HEAD states — a direct... og:url: https://daily.dev/posts/uber-open-sources-submitqueue-modal-rewrites-i-o-plane-in-go-mgakttc51 og:image: https://api.daily.dev/og/posts/MgaktTC51.png og:image:alt: Uber open-sources SubmitQueue, Modal rewrites I/O plane in Go 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. # Uber open-sources SubmitQueue, Modal rewrites I/O plane in Go **[Go Digest](https://daily.dev/sources/golang_digest)** · 4 min read · 4 upvotes · 0 comments ## Summary Uber open-sourced SubmitQueue, a Go-based speculative merge queue that validates multiple changes in parallel against predicted future HEAD states — a direct answer to the trunk stability problem in large monorepos. Modal rewrote its serverless Function Call server layer from Python to Go, cutting p50 latency by ~80ms and adding geographic routing across 4+ regions. Go 1.27 RC2 is out with the JetBrains release party set for August 25. A detailed benchmarking post on Redis leaderboard tie-breaking is worth reading for the methodology alone. ## Content **TLDR:** Uber open-sourced SubmitQueue, a Go-based speculative merge queue that validates multiple changes in parallel against predicted future HEAD states — a direct answer to the trunk stability problem in large monorepos. Modal rewrote its serverless Function Call server layer from Python to Go, cutting p50 latency by ~80ms and adding geographic routing across 4+ regions. Go 1.27 RC2 is out with the JetBrains release party set for August 25. A detailed benchmarking post on Redis leaderboard tie-breaking is worth reading for the methodology alone. --- ## Uber open-sources SubmitQueue, a speculative merge queue written in Go Rather than validating changes sequentially, SubmitQueue speculatively rebases and validates multiple changes in parallel against predicted future HEAD states. When a validation fails, it isolates the offending change and retries the rest automatically — no human intervention needed. The repo includes a Gateway, Orchestrator, and MySQL backend, runnable locally via Docker Compose. If you're running a fast-moving monorepo and dealing with flaky trunk, this is worth a close look. [Read more](https://daily.dev/posts/kbreev4b8) ## Modal rewrites serverless I/O plane in Go, cuts p50 latency by ~80ms Modal replaced its Python server layer with Go to handle gRPC concurrency better, moved non-critical work to async background tasks, and reduced hot-path Redis interactions. The result is ~80ms off p50 end-to-end latency and geographic distribution across 4+ regions with a routing_region option. Practical tips from the post: keep payloads under 2MiB and batch small inputs to reduce network hops. [Read more](https://daily.dev/posts/sxzUeP07r) ## Redis leaderboard tie-breaking: 11-17% write overhead, 3x memory cost Podium, an open-source Redis-backed leaderboard service, replaced lexicographic tie-breaking with deterministic first-arrival ordering using a per-leaderboard decrementing sequence stored in Redis and updated atomically via Lua script. The benchmarking post is unusually honest: writes cost 11-17% more latency, memory jumps from ~99 to ~287 bytes per member, and a 78% regression on 501-member bulk lookups is documented openly as an optimization target. The methodology — behavior correctness gates before performance gates, server-side memory measurement, publishing regressions alongside wins — is worth stealing regardless of whether you use Podium. [Read more](https://daily.dev/feed-by-ids?id=MmyQt0rIP&id=B55iowwy6) ## Go 1.27 RC2 out, release party August 25 Go 1.27 is in its second release candidate. The interactive tour from last week's digest is now the reference for what's landing: generic methods, goroutine leak profiler, uuid package, experimental portable SIMD. JetBrains is hosting a free online release party on August 25 at 4pm UTC with Robert Griesemer, Alan Donovan, and other Go team members streaming from Amsterdam. [Read more](https://daily.dev/feed-by-ids?id=FygkcXzyM&id=dgkBynCWp) --- ## Also notable - **pgx CollectRows was 1.8x slower and 10x more allocations — fixed in v5.6:** A deep dive found pgx's CollectRows API was 1.8x slower and allocated 10x more memory than a hand-written loop due to repeated reflection lookups and per-row heap escapes; patches landed in pgx v5.6, and the author also published pgx-collect as a drop-in replacement with a Scanner interface that runs setup once and reuses scan targets. [Read more](https://daily.dev/posts/wFMGvGSg0) - **FIPS 140-3 certification doesn't mean what most buyers think:** FIPS 140-3 certifies algorithm implementation at a specific firmware version only — not key management, operational config, or surrounding system security — and Go's FIPS-only mode panics on BIP32's first derivation step because HMAC with a 96-bit key falls below the 112-bit floor; over 90% of FIPS HSM buyers reportedly run them with FIPS mode disabled. [Read more](https://daily.dev/feed-by-ids?id=SsbNkb8jV&id=SBtkfnsra) - **Solod: a Go-subset language that compiles to C11:** Solod is a new systems language defined as a strict subset of Go — reusing Go's LSP, linters, and package management — that compiles to C11 via GCC or Clang, giving zero-cost C interop; it ports significant parts of Go's standard library with explicit allocators for manual memory management. [Read more](https://daily.dev/posts/iZFBk5fxY) - **ID-JAG OAuth draft re-implemented in Go for least-privilege agent token chains:** ID-JAG (Identity Assertion JWT Authorization Grant) is an IETF draft combining RFC 8693 and RFC 7523 to downscope tokens at each hop in a multi-agent chain; the author ported the reference MCP server from TypeScript to Go using modelcontextprotocol/go-sdk, with httptest-based test coverage simulating Athenz ZTS. [Read more](https://daily.dev/posts/7PZZHe2MC) ## Similar posts on daily.dev - [GitHub - uber/submitqueue: SubmitQueue is a high-performance speculative merge queue that keeps your trunk consistently green at scale.](https://daily.dev/posts/github---uber-submitqueue-submitqueue-is-a-high-performance-speculative-merge-queue-that-keeps-your-kbreev4b8) · Hacker News · 23 upvotes · 1 comments - [Bringing serverless functions to the speed of wire](https://daily.dev/posts/bringing-serverless-functions-to-the-speed-of-wire-sxzuep07r) · Modal · 6 upvotes · 1 comments - [I Built a Distributed Task Queue from Scratch with Go and PostgreSQL](https://daily.dev/posts/i-built-a-distributed-task-queue-from-scratch-with-go-and-postgresql-z4nw802lb) · Medium · 58 upvotes · 7 comments --- Tags: [#golang](https://daily.dev/tags/golang), [#serverless](https://daily.dev/tags/serverless), [#redis](https://daily.dev/tags/redis), [#uber](https://daily.dev/tags/uber) [View this post on daily.dev](https://daily.dev/posts/uber-open-sources-submitqueue-modal-rewrites-i-o-plane-in-go-mgakttc51) ```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":"DiscussionForumPosting","mainEntityOfPage":"https://daily.dev/posts/uber-open-sources-submitqueue-modal-rewrites-i-o-plane-in-go-mgakttc51","headline":"Uber open-sources SubmitQueue, Modal rewrites I/O plane in Go","text":"Uber open-sourced SubmitQueue, a Go-based speculative merge queue that validates multiple changes in parallel against predicted future HEAD states — a direct answer to the trunk stability problem in large monorepos. 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