Senior Platform Engineer

Sprig; United States; On-site; USD 140,000 - 180,000; Full time

Benefits offered by this job

Competitive Employee Equity

401K Program

Medical, Dental, Vision Benefits

Paid Time Off

Parental Leave

Work from Home Equipment Stipend

Professional Development Stipend

Flexible Work Options

Access to Sprig Offices

Company Events

Job summary

Sprig is seeking a seasoned Build Systems Engineer to own and modernize our large TypeScript, React, and Go monorepo platform. You’ll drive a faster, more predictable development loop with hermetic builds, incremental compilation, and robust test automation.

You will lead the migration of our JS toolchain to Bazel modules and optimize the CI/CD pipeline, including remote caches and per-branch environments, ensuring scalable reliability for billions of events daily.

Qualifications

• 6+ years building and owning a monorepo at scale.
• Experience with hermeticity, sandboxing, and cache invalidation.
• Proven ownership of flake detection and merge signals.
• Experience with Bazel or similar advanced build systems.

Responsibilities

• Own the end-to-end build and test loop for a large TypeScript/Go monorepo.
• Lead migration and modernization of the JavaScript/TypeScript toolchain (e.g., Bazel modules).
• Reduce CI time and cost via caching, incremental builds, and optimized test parallelism.
• Build observable telemetry for per-target timing, cache hit rate, and flake rate.

Skills

Monorepo build systems

Bazel

CI/CD pipelines

Test infrastructure

Frontend build tooling

Hermetic builds

Tools

Nx

Pants

Turborepo

Job description

• Agents pay off when engineers hand them whole changes, not incremental changes
• That makes the build-and-test loop the safety gate for the entire org: when CI is slow or flaky, teams lose time twice, once waiting and once re-running to sort noise from real failures
• Add a dozen agents validating against the same shared environment, and a workflow annoyance becomes an organization-wide bottleneck
• This role owns that loop
• You will be responsible for how quickly a change becomes a signal people trust, whether a human or an agent wrote it: incremental CI on a large TypeScript, React, and Go monorepo, test automation that is fast and meaningful from unit through browser and visual, and short-lived environments created and torn down per branch instead of queued
• We are not looking for someone to inherit a ticket queue
• We want a builder who can help set a direction for how development should work in an agent-heavy world, then deliver it
• If you have experience making a development loop people complain about faster and more predictable, this is the next iteration of that same problem, with tighter constraints
• You will do this on the Platform team, which runs the systems that support over a billion visitors a month and processes nearly a billion events a day
• Modernize the JavaScript and TypeScript build: Lead the migration from our current Node Bazel rules to a maintained successor, complete the move of the JS toolchain to Bazel modules, and replace accumulated image and packaging workarounds with proper module linking and incremental compilation
• Cut CI time and cost, measurably: Establish p50 and p95 PR build and test times as tracked metrics, then drive them down through better cache hit rates, incremental builds, and balanced test parallelism. Own the remote cache fleet's sizing, eviction behavior, and cost
• Make the build observable: Ship telemetry for per-target timing, cache hit rate, flake rate, and cost, so build decisions are data-driven rather than anecdotal
• Make test automation a first-class developer experience: Own how engineers and agents write, run, and trust tests across unit, integration, browser end-to-end, and visual layers. Make the local command match CI, make it trivial to run either a single file or the affected graph, and detect and quarantine flakes instead of asking people to rerun. Close the gaps so lint, static analysis, and coverage are real gates rather than noise
• Move from shared environments to epoxy ones: Replace a handful of long-lived, contended environments with short-lived isolated stacks that a human or a cloud agent can create per branch or per task. Fast spin-up, real isolation, and cost control are first-class requirements
• Build the agent-ready development platform: Deliver hermetic, sandboxed, reproducible build and test environments that agents can invoke safely and in parallel, plus the automated review and presubmit signals they need to validate their own changes

Benefits

• Competitive Employee Equity
• 401K Program
• Medical, Dental, and Vision Benefits
• Additional Wellbeing Benefits
• Generous Paid Time Off
• Paid Parental Leave
• Hardware & Software
• Work from Home Equipment Stipend
• Professional Development Stipend
• Flexible Work Options
• Access to Sprig Offices
• Company Events

TypeScript/Node fluency: Strong expertise in Node.js module resolution and packaging (CJS/ESM, exports) and comfortable operating in a polyglot repository alongside GoBuild trust: Experience eliminating hidden network calls, machine-dependent toolchains, and undeclared inputs to ensure reproducible results and prevent cache/sandbox poisoningCI/CD as a platform: Experience owning incremental builds, test sharding, self-hosted runner fleets, presubmit/postsubmit design, and merge queues, knowing that services and UI need different feedback loopsFrontend build ownership: Deep experience with production bundler pipelines (webpack, Vite, esbuild, or Turbopack), shared UI packages, and test suites (Jest, Playwright, Cypress) and their interaction with hermetic buildsBuild systems depth: 6+ years owning a monorepo build system at scale (Bazel strongly preferred; Buck2, Pants, Nx, or Turborepo also considered). You understand hermeticity, sandboxing, action graphs, and cache invalidation from first principlesTest infrastructure and impact: Proven ownership of flake detection/quarantine, balanced sharding, and merge signals, with measurable results in build times, CI spend, and artifact or bundle sizes